POPULARITY
Hosted by carolyn lam
2 episodes with carolyn lam
2 episodes with carolyn lam
2 episodes with carolyn lam
2 episodes with carolyn lam
2 episodes with carolyn lam
2 episodes with carolyn lam
In a special episode themed around Chinese New Year, we explore how Adelaide embraces cultural connections through three distinct lenses. The centerpiece is our conversation with Carolyn Lam, whose journey from Hong Kong to Adelaide has helped weave classical music into our city’s cultural fabric through Amicus Strings’ 100+ annual performances. The celebration begins with 23rd Street Distillery’s extraordinary Year of the Snake Whisky, one of only 3,600 bottles produced, showcasing Kangaroo Island barley aged in 15-year-old Galway Pipe casks. The resulting spirit proves as transformative as the year it honours. Our musical pilgrimage breaks new ground as we debut vinyl playback in the studio with Jayne-Anne Power’s “What’s Your Rush” from The Analogue Sessions, bringing soul-drenched wisdom to match the Year of the Snake’s themes of transformation and growth. You can navigate episodes using chapter markers in your podcast app. Not a fan of one segment? You can click next to jump to the next chapter in the show. We’re here to serve! The Adelaide Show Podcast: Awarded Silver for Best Interview Podcast in Australia at the 2021 Australian Podcast Awards and named as Finalist for Best News and Current Affairs Podcast in the 2018 Australian Podcast Awards. And please consider becoming part of our podcast by joining our Inner Circle. It’s an email list. Join it and you might get an email on a Sunday or Monday seeking question ideas, guest ideas and requests for other bits of feedback about YOUR podcast, The Adelaide Show. Email us directly and we’ll add you to the list: podcast@theadelaideshow.com.au If you enjoy the show, please leave us a 5-star review in iTunes or other podcast sites, or buy some great merch from our Red Bubble store – The Adelaide Show Shop. We’d greatly appreciate it. And please talk about us and share our episodes on social media, it really helps build our community. Oh, and here’s our index of all episode in one concisepage. Running Sheet: Snake Whisky And Symphony Herald Adelaide’s Chinese New Year 00:00:00 Intro Introduction 00:03:43 SA Drink Of The Week The South Australian Drinks Of The Week this week is the 23rd Street Distillery Year Of The Snake Whisky. The 23rd Street Distillery Year of the Snake Whisky arrives in packaging that would make any emperor proud – deep burgundy and gold boxes revealing a snake-adorned bottle that’s as much art piece as vessel. Our resident palate, John Gledhill, discovers layers of butterscotch and warming spices dancing with sun-dried raisins and vanilla, while the 15-year-old Galway Pipe cask influence emerges like a wise elder offering quiet counsel. 00:16:00 Carolyn Lam, Co-founder, Amicus Strings From playing in total darkness at Mawson Lakes Planetarium to accompanying Elaine Paige, OBE, Carolyn Lam’s musical journey embodies the cultural bridges being built in Adelaide. She shares insights on everything from making classical music accessible through popular music arrangements to the surprising connection between Philip Glass and organised personalities. Her reflections on Hong Kong’s vibrant classical music scene and the differences between Eastern and Western musical approaches offer fascinating glimpses into how music transcends cultural boundaries. Amicus Strings booking information Hong Kong String Orchestra performance details for January 31st at Her Majesty’s Theatre 00:50:55 Musical Pilgrimage In the Musical Pilgrimage, we feature What’s Your Rush by Jayne-Anne Power. In a first for the podcast’s 11-year history, we spin vinyl right in the studio with Jayne-Anne Power’s “What’s Your Rush” from The Analogue Sessions EP. The funked-up soul and gritty grooves perfectly complement our Chinese New Year theme of transformation and wisdom, with Shane Ellery’s keys and the powerful vocal harmonies creating a soundscape that rewards patient listening – truly embodying the “what’s your rush?” philosophy.Support the show: https://theadelaideshow.com.au/listen-or-download-the-podcast/adelaide-in-crowd/See omnystudio.com/listener for privacy information.
We are thrilled to welcome "Dr. Carolyn Lam" actress Lexa Doig to Dial the Gate to explore her career, filling the shoes of Stargate Command's chief medical officer, and putting up with Dr. Daniel Jackson on a daily basis!
They Call Me Rommie (Replay) Lexa Doig of Andromeda, Stargate SG-1, Arrow, Flash Gordon, and so many other shows joined us to talk about her career, life, and even some questions from our listeners and social media followers. Lexa tells us about working on Andromeda, Jason X, and even what it was like to work on set with her husband, Michael Shanks, as the character Carolyn Lam. And were you aware of the Cat Distribution system? We were not. But we did find out how Lexa got "Grey Cat" ... apparently it was through the Cat Distribution System ... Also, find out what characters Lexa would like to play again and if she would make any changes to those characters! For more on Lexa Doig, please visit the following - Google - Lexa Doig Most social media platforms - @lexadoig For more on our show partners - Tee See Tee (Use Code FSF15) - www.teeseetee.com Level Up Sabers https://bit.ly/FSFLevelUpSabers Storylines Editing - https://www.storylines.video/ Win free loot - sign up here - www.fsfpopcast.com/contact Tim Beisiegels articles - https://couchsoup.com/author/byeseagull For more on our Show - Join our Patreon https://patreon.com/fsfpopcast Join our Discord! https://discord.gg/cpry4fCDTq Visit our website - https://www.fsfpopcast.com FSF PopCast on Twitter, Instagram, and Threads - @fsfpopcast
They Call Me Rommie (Replay) Lexa Doig of Andromeda, Stargate SG-1, Arrow, Flash Gordon, and so many other shows joined us to talk about her career, life, and even some questions from our listeners and social media followers. Lexa tells us about working on Andromeda, Jason X, and even what it was like to work on set with her husband, Michael Shanks, as the character Carolyn Lam. And were you aware of the Cat Distribution system? We were not. But we did find out how Lexa got "Grey Cat" ... apparently it was through the Cat Distribution System ... Also, find out what characters Lexa would like to play again and if she would make any changes to those characters! For more on Lexa Doig, please visit the following - Google - Lexa Doig Most social media platforms - @lexadoig For more on our show partners - Tee See Tee (Use Code FSF15) - www.teeseetee.com Level Up Sabers https://bit.ly/FSFLevelUpSabers Storylines Editing - https://www.storylines.video/ Win free loot - sign up here - www.fsfpopcast.com/contact Tim Beisiegels articles - https://couchsoup.com/author/byeseagull For more on our Show - Join our Patreon https://patreon.com/fsfpopcast Join our Discord! https://discord.gg/cpry4fCDTq Visit our website - https://www.fsfpopcast.com FSF PopCast on Twitter, Instagram, and Threads - @fsfpopcast
They Call Me Rommie Lexa Doig of Andromeda, Stargate SG-1, Arrow, Flash Gordon, and so many other shows joined us to talk about her career, life, and even some questions from our listeners and social media followers. Lexa tells us about working on Andromeda, Jason X, and even what it was like to work on set with her husband, Michael Shanks, as the character Carolyn Lam. And were you aware of the Cat Distribution system? We were not. But we did find out how Lexa got "Grey Cat" ... apparently it was through the Cat Distribution System ... Also, find out what characters Lexa would like to play again and if she would make any changes to those characters! For more on Lexa Doig, please visit the following - Google - Lexa Doig Most social media platforms - @lexadoig Win free loot with our monthly email giveaways - sign up here - www.fsfpopcast.com/contact Tim Beisiegels Star Wars Articles - https://dorksideoftheforce.com/author/tbeisiegel Tim Beisiegels Pop Culture Articles - https://couchsoup.com/author/byeseagull For RSWOF Merch - https://www.teepublic.com/t-shirt/319.... 100% of all proceeds benefit Wish Upon a Teen For direct contributions - https://www.wishuponateen.org Join our Patreon https://patreon.com/fsfpopcast Join our Discord! https://discord.gg/cpry4fCDTq Visit our website - https://www.fsfpopcast.com FSF PopCast on Twitter and Instagram - @fsfpopcast Buy us Coffee - https://ko-fi.com/fsfpopcast For more on our show partners - Tee See Tee (Use Code FSF15) - www.teeseetee.com Monkey Cult Coffee (use code FSF10) - https://monkeycultcoffee.com/ Level Up Sabers https://bit.ly/FSFLevelUpSabers Big Boy Graphics - Bigboygraphics.etsy.com
They Call Me Rommie Lexa Doig of Andromeda, Stargate SG-1, Arrow, Flash Gordon, and so many other shows joined us to talk about her career, life, and even some questions from our listeners and social media followers. Lexa tells us about working on Andromeda, Jason X, and even what it was like to work on set with her husband, Michael Shanks, as the character Carolyn Lam. And were you aware of the Cat Distribution system? We were not. But we did find out how Lexa got "Grey Cat" ... apparently it was through the Cat Distribution System ... Also, find out what characters Lexa would like to play again and if she would make any changes to those characters! For more on Lexa Doig, please visit the following - Google - Lexa Doig Most social media platforms - @lexadoig Win free loot with our monthly email giveaways - sign up here - www.fsfpopcast.com/contact Tim Beisiegels Star Wars Articles - https://dorksideoftheforce.com/author/tbeisiegel Tim Beisiegels Pop Culture Articles - https://couchsoup.com/author/byeseagull For RSWOF Merch - https://www.teepublic.com/t-shirt/319.... 100% of all proceeds benefit Wish Upon a Teen For direct contributions - https://www.wishuponateen.org Join our Patreon https://patreon.com/fsfpopcast Join our Discord! https://discord.gg/cpry4fCDTq Visit our website - https://www.fsfpopcast.com FSF PopCast on Twitter and Instagram - @fsfpopcast Buy us Coffee - https://ko-fi.com/fsfpopcast For more on our show partners - Tee See Tee (Use Code FSF15) - www.teeseetee.com Monkey Cult Coffee (use code FSF10) - https://monkeycultcoffee.com/ Level Up Sabers https://bit.ly/FSFLevelUpSabers Big Boy Graphics - Bigboygraphics.etsy.com
Dr. Terence Tan from AWS sits down with Dr. Carolyn Lam and James Hare of Us2.ai who are democratizing echocardiograms through AI. Learn about their regulatory & technical strategy, global impact, and advice for founders.
This week, please join Carolyn Lam and author Frans Van de Werf as they discuss the article "STREAM-2: Half-Dose Tenecteplase or Primary Percutaneous Coronary Intervention in Older Patients With ST-Segment−Elevation Myocardial Infarction: A Randomized, Open-Label Trial." For the episode transcript, visit: https://www.ahajournals.org/do/10.1161/podcast.20230828.941314
This week, please join author Kavita Sharma and Associate Editor Svati Shah as they discuss the article "Myocardial Metabolomics of Human Heart Failure With Preserved Ejection Fraction." Dr. Greg Hundley: Welcome listeners, to this April 11th issue of Circulation on the Run. And I am one of your cohosts, Dr. Greg Hundley, director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Peder Myhre: And I am Dr. Peder Myhre from Akershus University Hospital, and the University of Oslo in Norway. Dr. Greg Hundley: Well, Peder, wow. This week's feature discussion, very interesting. We spend a lot of time, especially with our colleague, Dr. Carolyn Lam, on heart failure preserved ejection fraction. But this week's feature discussion, it's going to focus on some of the myocardial metabolomics in this condition. But before we get to that, how about we grab a cup of coffee, and jump into some of the other articles in the issue? How about if I go first? Dr. Peder Myhre: Let's go, Greg. Dr. Greg Hundley: Okay. So Peder, some believe that cardiovascular disease may be the main reason for stagnant growth in life expectancy in the United States since 2010. And so, the American Heart Association, as you know, recently released an updated algorithm for evaluating cardiovascular health. Life's Essential 8, and it has a very nice score. So these authors, led by Dr. Lu Qi, from Tulane University, aimed to quantify the associations of the Life Essential 8 scores with life expectancy in a nationally representative sample of US adults. And the team included 23,000 non-pregnant non- institutionalized participants who were age 20 to 79 years, who participated in the National Health and Nutrition Examination survey, or NHANES, from 2005 to 2018. And whose mortality was identified through linkage to the National Death Index, from the period extending through December of 2019. Dr. Peder Myhre: Oh wow. So really, a validation of the Life's Essential 8. Greg, that's so interesting. What did they find? Dr. Greg Hundley: Right Peder, as you say, very interesting. So here are some of the data, and let's itemize them. So, during a median of 7.8 years of follow up, 1,359 total deaths occurred. Now, the estimated life expectancy at age 50 was 27.3 years, 32.9 years, and 36.2 years, in participants with low Life's Essential 8 scores, less than 50. Moderate, so Life's Essential 8 scores of greater than or equal to 50, but less than 80. And then, high scores, greater than 80. Okay? So equivalently, participants with high Life's Essential 8 scores had an average of 8.9 more years of life expectancy at age 50, compared to those with low scores. Next, on average, 42.6% of the gained life expectancy at age 50, from adhering to sort of that cardiovascular health, those recommendations, was attributable to reduced cardiovascular death. Next, significant associations with the Life's Essential 8 score and life expectancy were observed in both men and women. Next, similarly significant associations of cardiovascular health, Life's Essential 8, with life expectancy were observed in non-Hispanic Whites and non-Hispanic Blacks, but not in those originating from the country of Mexico. So Peder, finally, in summarizing all of this, adhering to the cardiovascular health lifestyle, defined by the Life's Essential 8 score, it was related to a considerably increased life expectancy. However, because of the findings from the individuals from the country of Mexico, more research is needed to be done in some of these minority groups, and particularly, those of Hispanic ethnicity, and perhaps other races. Dr. Peder Myhre: Oh, wow. Very interesting. And I would love to learn more about this subgroup analysis in future studies. So Greg, the next paper is about the hospitalization for heart failure measures. Because contemporary measures of hospital performance for heart failure hospitalization, the 30-day risk standardized readmission and mortality rate, are estimated using the same risk adjusted model and overall event rate for all patients. Thus, these measures are mainly driven by the care quality and outcomes for the majority racial ethnic groups, and may not adequately represent the hospital performance for patients of Black or other races. And in this study, led by co-corresponding authors, Mentias from Cleveland Clinic and Pandey from University of Texas Southwestern Medical Center, the authors used fee for service Medicare beneficiaries from 2014 to 2019 hospitalized with heart failure, in hospital level 30 day risk standardized remission and mortality rates were estimated using traditional race agnostic models and the race specific approach, with measures derived separately for each race ethnicity group. Dr. Greg Hundley: Ah, very interesting, Peder. So what did they find from this study? Dr. Peder Myhre: So the study included more than 1.9 million patients, comprising of 75% White patients, 15% Black patients, and 10% patients of other races, with heart failure from 1,860 hospitals. And compared with the race agnostic model, composite race-specific metrics for all patients demonstrated stronger correlation with 30 days readmissions. And that is correlation coefficient 0.78 versus 0.63, and 30 day mortality rate 0.52 versus 0.29 for Black patients. In concordance in hospital performance was for all patients and patients of Black race was also higher with race specific as compared to race agnostic metrics. So Greg, the authors conclude that among patients hospitalized with heart failure race specific 30 day risk standardized remission and mortality rates are more equitable in representing hospital performance for patients of Black and other races. Dr. Greg Hundley: Very nice, Peder. What a beautiful summary in a very elegant study. Peder, myocardial insulin resistance is a hallmark of diabetic cardiac injury. However, the underlining molecular mechanisms for this relationship remain unclear. Now, recent studies demonstrate, that the diabetic heart is resistant to several cardioprotective interventions, including adiponectin and pre-conditioning. The universal quote, unquote, resistance to multiple therapeutic interventions suggest, impairment of the requisite molecule, or molecules, involved in broad pro survival signaling cascades. Now caveolin is a scaffolding protein coordinating trans-membrane signaling transduction. However, the role of caveolin-3 in diabetic impairment of cardiac protective signaling and diabetic ischemic heart failure is unknown. And so these investigators, led by Dr. Xinliang Ma, from Thomas Jefferson University, studied mice fed a normal diet or high fat diet for two to 12 weeks, and subjected them to myocardial ischemia and reperfusion. Dr. Peder Myhre: Oh wow. What an interesting preclinical science paper, Greg. What did they find? Dr. Greg Hundley: Right. So the authors found that nitration of caveolin-3 at tyrosine 73 and resulted signal complex dissociation was responsible for cardiac insulin adiponectin resistance in the pre-diabetic heart. And this contributed to ischemic heart failure progression. Now, early interventions preserving caveolin-3 centered signal zone integrity was found to be an effective novel strategy against diabetic exacerbation of ischemic heart failure. And Peder, I think these very exciting results suggest that this is a new area of research and further experiments are warranted. And there's a very nice editorial by Professor Heidenreich, entitled “Pursuing Equity in Performance Measurement. Well Peder, there's some other articles in this issue, and we'll dip in this week to the mail bag, for a Research Letter from Professor Hibbert, entitled “Utility of a Smartphone Application in Assessing Palmar Circulation Prior to Radial Artery Harvesting for Coronary Artery Bypass Grafting.” Dr. Peder Myhre: That is so cool. And we also have a Letter from Dr. Kim, regarding the article entitled, “Detection of Atrial Fibrillation in a Large Population Using Wearable Devices: The Fitbit Heart Study.” Dr. Greg Hundley: Very nice. Well, how about we get along to one of Carolyn's favorite topics, heart failure with preserved ejection fraction, and learn more about myocardial metabolomics? Dr. Peder Myhre: Can't wait. Dr. Carolyn Lam: Today's feature discussion is on my favorite topic, heart failure with preserved ejection fraction, or HFpEF. But today, what we're focusing on is truly novel. We are looking at the myocardial metabolomics of human HFpEF, very, very valuable data and insights. We're so pleased to have with us the corresponding author of today's feature paper, Dr. Kavita Sharma, who's from the Johns Hopkins University School of Medicine, and our associate editor, Dr. Svati Shah, who's, of course, from Duke University School of Medicine. So welcome Kavita and Svati. Kavita, if I could start by, please put us and bring us all to the same level of knowledge, by perhaps explaining in simple terms, what is metabolomics? And what is normal versus perhaps abnormal metabolomics, in a known condition, like systolic heart failure or heart failure with reduced ejection fraction? Dr. Kavita Sharma: Sure. Well thank you, Carolyn, for the opportunity to chat around this topic. And it's great to be with you and Svati this morning. Metabolomics is a broad general study of essentially, all the chemical processes involving metabolites, or small molecule substrates, their intermediates, and even the products of cellular metabolism. This can be studied in really, any organ system, in any organ. What is really unique, I think, to this particular paper in our project is that, it has yet to have been defined or described in human HFpEF from the myocardial tissue. We call this heart failure with preserved ejection fraction, and inherent to that name in this complicated syndrome is that, there is something probably wrong with the heart, yet we have not really had much insight to what that might be from direct myocardial tissue. We are also still learning about what metabolomics looks like in, for example, the heart failure with reduced ejection fraction state. Though, there is more published in this space than in HFpEF. From the limited knowledge that we have, it does appear that heart failure with reduced ejection fraction hearts, and this is certainly seen in the plasma, which is where most of metabolomic studies have generated from, those hearts tend to utilize various forms of energy banks, if you will. Whether that's fatty acid oxidation, whether that is glucose utilization or intermediates and so on. And our primary interest was to understand, how do the preserved EF parts in patients fare in comparison? Dr. Carolyn Lam: Oh, thank you so much, Kavita. That was beautifully explained. And indeed, what's so special about your paper is, it's not just circulating metabolites but myocardial metabolites. And you have the control groups that are so important to study at the same time. So patients with HFpEF, but also those with HFrEF and versus controls. And thank you for establishing too, that if I'm not wrong, fatty acid metabolism accounts for the majority of ATP generation in the normal heart. Whereas, this declines a little in the HFrEF heart. And now, I think we're about to find out what happens in the HFpEF heart. So if you could explain what you did and what you find. Dr. Kavita Sharma: Yes, absolutely. So we examined, again, tissue and plasma metabolomics from 38 subjects with HFpEF. These are patients referred to the Hopkins HFpEF Clinic. And so they have been essentially, clinically evaluated, and have what we define as HFpEF, based on hemodynamic testing. So a right heart catheterization, often with exercise, that meets criteria for diagnosis of the syndrome. As you stated, we compared our HFpEF patient tissue and plasma samples to samples coming from patients with HFrEF, dilated cardiomyopathy, and non-failing controls. And the latter two sources were a tissue bank from the University of Pennsylvania, that is long-standing, where patients with endstage dilated cardiomyopathy are able to have tissue banked at the University of Pennsylvania at the time of explant prior to transplant. So albeit, we are comparing to fairly advanced end stage dilated cardiomyopathy, and control tissue comes from unused donor hearts, essentially. So presumably, normal heart function patients, likely in a brain death state, who for whatever reason, the hearts were not utilized for transplantation. Again, not an entirely perfect controlled state, but again, given the nature of the work, the fact that it's myocardial tissue, the closest that we have found we've been able to come to for a control comparison. We started out performing what we call quantitative targeted metabolomics. We measured organic acids, amino acids, and acylcarnitines in the myocardium. And that was totaling around 72 metabolites. And we did the same in plasma, so close to 69 metabolites. And our metabolomics work was actually completed at the University of Pennsylvania. And so, I wish to credit Dr. Zoltan Arany and Dr. Dan Kelly for their great collaboration in this study. Dr. Carolyn Lam: That's wonderful. Kavita, if you could tell us a little bit more about the patients with HFpEF. We understand it was end stage dilated cardiomyopathy, HFrEF, and donor hearts as the controls, but the patients with HFpEF, in relation to obesity, diabetes, and how that may impact the interpretation of the results. Dr. Kavita Sharma: Sure. So these are HFpEF patients that are in an ambulatory state outpatient setting. They have many of the comorbidities we know are intrinsic today to HFpEF. Out of our HFpEF population, the majority were women. So 71%, that's 27 out of the 38 we serve. And we're very fortunate to serve a African-American enriched population in Baltimore that's intrinsic to our center. And so, over half of our patients were Black. The remaining Caucasian, one non-Caucasian. Over half had been hospitalized, for example, in the prior one year. So these are certainly symptomatic patients. And all had NYHA II or greater symptoms. We do have a rather obese cohort at Hopkins. And so, our median BMI, for example, was 39, our mean is very similar. And the majority have, as we see often in HFpEF, the majority with hypertension, over half with diabetes. In fact, it was actually 70% or so. Rather few with coronary disease, and this is a trend we're seeing in general in HFpEF in the present day kind of common phenotypes, and about a third with atrial fibrillation. So really, representative, I think, of this kind of cardiometabolic as we call it, phenotype of HFpEF, that is the predominant phenotype we're seeing, at least in North America. Dr. Carolyn Lam: Oh, that's perfect. And then, maybe just a few words about the results before I bring Svati in for her thoughts. Thanks. Dr. Kavita Sharma: Sure, absolutely. So we conducted this study in a couple different stages. We first started with performing a principal component analysis and hierarchical clustering analysis, to see whether the myocardial metabolites and the plasma metabolites, respectively, would they distinguish these three patient groups? So HFpEF from HFrEF and controls. And interestingly, in the myocardial tissue, our PCA analysis and our hierarchical clustering analysis show that actually, in fact, as few as 70 metabolites in the myocardium really distinctly differentiate these three subgroups. The top contributors that separated HF from controls, for example, and HFrEF, were mostly related to amino acids, including branched chain amino acids and their catabolites, as well as medium and long chain acylcarnitines, which are byproducts of fatty acid oxidation. When it came to the plasma metabolome, on the other hand, there was far less distinguishing between the groups, and significant overlap, both in PCA and hierarchal clustering. And really, the take home there is that, the myocardial tissue and the plasma were really quite distinct for the overall metabolite analysis. But then, even as we broke it down by fatty acid oxidation, by glucose metabolism, and even branched chain amino acids, we saw this trend continue, that the plasma was quite distinct from the myocardial tissue. Now, which of the two is more representative of the disease state? Which is the one that we should be paying more attention to? I think that remains to be fully understood further. And of course, it would be really nice to replicate these findings in another cohort. But that is something that, I think, is a first, that certainly, that we have seen and important for the community. Dr. Carolyn Lam: Indeed. Oh, Kavita, we could go on talking forever, but I'd really love Svati's thoughts. Why was this paper so special? What does it tell us clinically with any implications? Dr. Svati Shah: Yeah. I just want to commend Dr. Hahn, Dr. Sharma, on this incredible work. If you can just imagine how much painstaking work this took for Dr. Sharma and Dr. Hahn. It's a very careful phenotyping of HFpEF. These are true HFpEF patients. The ability to get tissue, and to pair the tissue to the plasma, so that we can really understand. When we measure things in the circulation, and we think they're telling us about the heart, are they actually telling us about the heart? So I really want to commend this incredible work. And Carolyn, I love talking about cardiac metabolism, because the heart is an incredible organ, right? The heart is a metabolic omnivore. It'll eat many different kinds of fuels, and a lot of different things determine which fuels it uses. And as you nicely outlined, Carolyn, earlier, in the normal heart, the heart prefers to use fatty acids. But what we are not completely certain of is, what happens in HFpEF? So in HFrEF, we know that the heart switches to glucose, which is not a great fuel, actually. It's actually, a metabolically inefficient fuel. And so we know in HFrEF, that the heart has this metabolic inflexibility. All of a sudden, it's not an omnivore, and it's kind of stuck with certain fuels, which are not very healthy for it. But what Dr. Sharma and Dr. Hahn have shown, for the first time really, is what happens in HFpEF? And so, I think it's really cool that, actually, it just highlights how complex HFpEF is as a disease. So they were able to show that in some ways, HFpEF is similar to HFrEF, including that there's impairments in use of these fatty acids, which is what the normal heart does. But, they also show that HFpEF may be different than HFrEF in many ways, including, because of these branched chain amino acids. And that may be because of some of the clinical differences that we know exist in patients with HFpEF, including the obesity and diabetes, that Dr. Sharma nicely outlined. Although, I want to point out, they were very careful about trying to take these clinical factors into account when they looked at differences in the metabolites. So really incredible work, highlighting that the HFpEF heart also has this metabolic inflexibility. It also is not a metabolic omnivore like the normal heart is, but highlighting important differences, potentially, between HFpEF and HFrEF. Dr. Carolyn Lam: Oh, Svati, thank you for putting that so clearly. Dr. Kavita Sharma: No, I think that was a really elegant summary of the findings, Svati. And thank you for your kind words and support in allowing us to share our work through Circulation. I really couldn't say it better, but that's exactly what we seem to find is that, when we look at various sort of stores or banks of energy resource, what we really found is that these HFpEF hearts are energy inflexible, as Svati said, that begins with fatty acid metabolism. And so, when we look at, for example, medium and launching acylcarnitines, what we find is that these are markedly reduced in HFpEF myocardial tissue, quite similar to HFrEF. Again, both of them reduced compared to controls. And again, these are byproducts of fatty acid oxidation, and that is really responsible for almost 80% of generally what we think of energy metabolism in the normal state. In the plasma, however, again, back to that theme where we don't see that reproduced in the plasma, we find that HFpEF is actually not too dissimilar from controls for certain medium and long chain acylcarnitines, and then closer to HFrEF in some cases. And interestingly, we compared our metabolomics study to our prior report of our RNA sequencing paper, that was also published in Circulation now two years ago. And what we found is that, there is reduced gene expression of many of the proteins involved with fatty acid uptake and oxidation, when we compare them to control states. So the story is sort of, fits with what we have seen previously, and when we focus in on this group of genes. Our analysis of glucose metabolism though, did not include glycolysis or glucose oxidation intermediates. We still found that, majority of the TCA cycle intermediate, so succinate, for example, fumarate, malate, were all reduced in HFpEF versus control. It was really only pyruvate in isolation that was increased in HFpEF myocardium, compared to controls. And again, a number of genes implicated in glucose metabolism in general, we found to be lower in HFpEF versus control, including gluten 1, or SLC2A1, which is involved in glucose uptake. So again, this theme of, we have patients with significant obesity, many in the diabetic state, we would think that these hearts would utilize these energy stores, but they don't seem to be. And finally, we see distinct differences in the tissue and branched chain amino acid pathways as well. There appears to be some sort of a block between the branched chain amino acids, and then sort of byproducts, as you continue down through ketoacids and further. And we don't fully understand where those blocks are, but that was certainly notable. And then lastly, I'll say, one interest that we've had, and really, what led to much of this work in the tissue, is to pursue what we call deep phenotyping. Can these molecular signatures, whether it's gene expression, or metabolomics, or what we're working on now, which is proteomics, can these really help us identify unique subgroups within HFpEF? And so, we've tried to do that with the metabolomics, and we found that, using various sort of clustering analytical methods, in fact, there is significant overlap, as it turns out, within HFpEF, when it comes to the metabolomic signatures. And we only found, really, two subgroups within HFpEF. And even these two really did not have much that distinguished them, beyond branched chain amino acids. And so, this is the first time, at least that our group has seen, at a tissue level, that there is actually a fair bit of homogeneity now in the metabolomic signatures, compared to our RNA sequencing work. And that may be reflective of now, this increasingly cardiometabolic phenotype of HFpEF. And now, we may be seeing signs of that at the clinical and at the treatment level, where we have therapies like SGLT2 inhibitors, that are showing benefit to what seems to be a much broader spectrum of HFpEF, compared to prior therapies. So a lot of questions that have been generated from the work, and we're looking forward to exploring much of this in more detail. Dr. Carolyn Lam: And Svati, may I give you the last word? Where do you think this field is headed next? Dr. Svati Shah: I think there's so much to do, and I think Dr. Sharma and Dr. Hahn have highlighted how much work there is to do in this space. We're brushing the surface and understanding cardiac metabolism with this really important paper. But Carolyn, as you pointed out, we really need to understand what happens to these patients over time? What happens to, not just cardiac metabolism, but molecular biology more broadly, in patients with HFpEF with these various treatments? Including now, thank goodness, we have SGLT2 inhibitors as a therapeutic intervention for patients with HFpEF. And in fact, we published in Circulation a few months ago, a paper led by a very talented junior faculty, Senthil Selvaraj, where we actually showed that these acetylcarnitine levels that reflect fatty acid oxidation actually are changed by SGLT2 inhibitors, and are associated with changes in clinical outcomes in HFpEF. So we really need larger sample sizes, being able to look at these patients in a longitudinal fashion. But really, doing what Dr. Sharma and Dr Hahn have done, which is careful, careful phenotyping and multidisciplinary teams, so that we can understand the molecular biology, as well as the clinical implications. Dr. Carolyn Lam: Oh, wow. Thank you so much, Kavita and Svati, for this incredible interview. I learned so much, and enjoyed it so thoroughly, as I'm sure our listeners did as well. Well, listeners, you've been listening to Circulation on the Run. Thank you for joining us today, and don't forget to tune in again next week. Dr. Greg Hundley: This program is Copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors, or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Milind Desai and Associate Editor Mark Link as they discuss the article "Dose-Blinded Myosin Inhibition in Patients With Obstructive Hypertrophic Cardiomyopathy Referred for Septal Reduction Therapy: Outcomes Through 32 Weeks." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr Greg Hundley, Associate Editor, Director of the Poly Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Oh, Greg. Today's feature paper is just so, so important. It's the long-term follow up or the longer term follow up of the VALOR-HCM trial. And this, if I can remind you, examined the effect of mavacampten on the need for septal reduction therapy in patients with intractable symptoms from obstructive hypertrophic cardiomyopathy. So we're going to hear the results through 32 weeks, but not until we discuss the other papers in today's issue. And I'd like to go first. I'd like to tell you about a paper that really provides the foundation for deciphering chamber selective gene transcription. So in this study from Dr. William Pu of Boston Children's Hospital and colleagues, authors mapped the chromatin features of atrial and ventricular cardiomyocytes and nominated candidate chamber selective enhancers based on differential features. The candidate enhancers were tested in vivo using adeno associated virus delivered massively parallel reporter assay leading to identification of 229 chamber selective enhancers. They then characterized chromatin features of these chamber selective enhancers and used dense mutagenesis to identify their essential features. Altogether the study suggested that estrogen-related receptor promoted ventricular chamber selective enhancer activity. They validated this prediction by showing that estrogen-related receptor inactivation led to loss of ventricular cardiomyocyte identity. So in aggregate, the studies yielded a rich resource of chamber selective chromatin features and chamber selective enhancers, and began to unravel the molecular basis for chamber selective transcriptional programs. Dr. Greg Hundley: Wow. So Carolyn, estrogen-related receptor promotion and then inactivation and finding really very interested preclinical results. So tell us now what are the clinical implications of this very nice study. Dr. Carolyn Lam: Wow. I mean, there are just so many implications. It can facilitate functional interpretation of genetic associations between variants and cardiac disease. Of course, it opens the doors to potential gene therapies and regenerative medicine and finally, identification of transcription regulators of the chamber identity really yield important mechanistic insights into the pathogenesis of important diseases like atrial fibrillation and cardiomyopathy. Dr. Greg Hundley: Wow, Carolyn, beautifully summarized. Well, my next paper pertains to COVID vaccines. So Carolyn, as we have seen SARS-CoV-2 targeted mRNA vaccines are a life-saving medical advancement developed to combat, of course, the COVID-19 pandemic. But in rare cases, some individuals can develop myocarditis following these mRNA vaccinations. Cases of adolescents and young adults developing post vaccine myocarditis have been reported globally, although the underlying immuno profiles of these individuals, they really haven't been described in detail. So these authors led by Dr. Lael Yonker from Massachusetts General Hospital, performed extensive system serology SARS-CoV-2 specific T-cell analysis and cytokine and SARS-CoV-2 antigen profiling on blood samples collected from adolescents and young adults either developed myocarditis or were asymptomatic following SARS-CoV-2 targeted mRNA vaccination. Dr. Carolyn Lam: Wow. Wow. Important question. Everyone's interested in the results. So what did they find? Dr. Greg Hundley: Right, Carolyn. So 16 cases with post vaccine myocarditis and 45 asymptomatic vaccinated controls were enrolled with extensive antibodies profiling, including assessment for autoantibodies or antibodies against the human relevant virome. And Carolyn, they found that T-cell responses were essentially indistinguishable from controls despite a modest increase in cytokine production. Notably, markedly elevated levels of full length spike protein unbound by antibodies were detected in the plasma of individuals with post vaccine myocarditis, a finding that was absent. It was absent in the asymptomatic vaccinated controls. So Carolyn, in conclusion, immunoprofiling of vaccinated adolescents and young adults revealed that the mRNA vaccine-induced immune responses did not differ between individuals that developed myocarditis versus individuals that did not. However, free spike antigen was detected in the blood of adolescents and young adults who developed post mRNA vaccine myocarditis. Now while this finding does not alter the risk benefit ratio favoring vaccination against COVID-19 to prevent severe clinical outcomes, it may provide some insight into the potential underlying etiology associated with post mRNA vaccine-induced myocarditis. Carolyn, this is accompanied by a wonderful editorial by Dr. Biykem Bozkurt indicating that these results raise a question as to why the circulating spike protein levels remain elevated despite adequate levels and functionality of the anti-spike antibodies. Well, Carolyn, we do have some other articles in the issue and from the mailbag we have a research letter from Professor Cho entitled PERM1 Protects the Heart From Pressure Overload Induced Dysfunction by Promoting Oxidative Metabolism. Also, there's a new drugs and devices piece from Professor Kabatano entitled Pharmacology and Clinical Development of Factor XI inhibitors. And then Tracy Hansen has a wonderful cardiology news summary regarding articles entitled The Study Reveals Rapid Intestinal Adaptations after Switching to High Fat Diet From Cell Research. Another article entitled New Insights into Immunotherapy Related Myocarditis from Nature. And finally, an article entitled Scientist Identified Genetic Variants Linked to Longevity published in the Journal of Science. Dr. Carolyn Lam: Wow. Interesting. There's also an exchange of letters between Drs. Monzo and Shah regarding the article, “Metabolomic Profiling of Effects of Dapagliflozin in Heart Failure with Reduced Ejection Fraction.” That is a Perspective piece by Dr. Davenport on contrast induced acute kidney injury and cardiovascular imaging, danger or distraction? Wow. What a beautiful issue. Thank you so much, Greg. Let's go to our feature discussion, shall we? Dr. Greg Hundley: Absolutely. Welcome, listeners, to this feature discussion on March 14th. And we have with us today Dr. Milind Desai from Cleveland Clinic in Cleveland, Ohio, and our own associate editor, Dr. Mark Link from University of Texas Southwestern Medical Center in Dallas, Texas. Welcome, gentlemen, Milind, we'll begin with you and bringing to us this study of mavacampten. Can you describe for us some of the background information that went into the preparation of this study, and what was the hypothesis that you wanted to address? Dr. Milind Desai: Thank you to the editorial staff, Dr. Hundley and the editorial staff at Circulation. So yes, mavacampten, as we know, is a novel first in class cardiac myocin inhibitor that was developed in the context of managing patients with hypertrophic obstructive cardiomyopathy. So the preliminary early stage studies have shown that it helped significantly in reducing outflow tract gradients as well as improved symptoms. But we wanted to take the conversation a bit further. In highly symptomatic patients, the current standard of care treatment is septal reduction therapy, which requires an experienced center and an experienced set of providers. So what we wanted to see was in such patients that are referred for septal reduction therapy, what does mavacampten do versus placebo? So does it reduce the need for septal reduction therapy? We divided the study into three parts. The first part was the placebo controlled 16 week study. The second part was we wanted to see what happens when the placebo arm crossed over to mavacampten and the mavacampten arm continued long-term. And that was the genesis of the study that we are discussing today. Dr. Greg Hundley: Very nice. So we've got a planned study, patients with hypertrophic cardiomyopathy, they ordinarily, because of guideline related therapeutic recommendations would undergo septal reduction therapy, but before that you're going to randomize patients to mavacampten versus a placebo. So we've sort of described a little bit the study design, and let's clarify specifically perhaps the study population and how many patients did you enroll? Dr. Milind Desai: Yes. In the original study, we enrolled 112 patients, 56 to mavacampten and 56 to placebo. After week 16, four patients, two of which underwent SRT and two withdrew consent. So essentially for the 32 week analysis, we had 108 patients, 56 in the mavacampten group and 52 in the placebo group that crossed over to mavacampten. So 108 patients. Dr. Greg Hundley: Very nice. So Milind, what were your study results? Dr. Milind Desai: Yes. What we found was at week 16, we have previously demonstrated that the group that got randomized mavacampten had a significant reduction in outflow tract radius, both resting and Valsalva, as well as biomarkers. And at week 16, what we found was 82% patients from the original group did not meet criteria for septal reduction therapy. So a hundred percent to begin with, 82%, that was at week 16. What we wanted to see, is the effect continued longer lasting and what happens to the placebo group that crossed over? So essentially what we found was at week 32, 89% of the total population no longer met criteria for septal reduction therapy. In addition to that, the mavacampten group continued to have reduced outflow tract gradients, continued improvement in Kansas City Score as well as biomarkers. But more importantly, the similar findings were demonstrated in the placebo arm that cross over to the mavacampten where, again, a significant proportion continued to show improvement in outflow tract gradient, Kansas City Score, as well as biomarker. The important point here in this study was at week 32, 95% patients chose to remain on medical therapy as opposed to going for SRT. Remember, a hundred percent patients were referred at the outset to undergo SRT. Dr. Greg Hundley: And Milind, did you notice any differences in your study results based on the age of the patients or based on their sex? Dr. Milind Desai: No, actually, we did not. This had a beneficial effect across gender, age, all the other variables. In fact, this is one of the strengths of the study because almost 50% patients that were randomized were women. So this was well represented across different genders. Dr. Greg Hundley: And then you mentioned a marked reduction in the gradient across the left ventricular outflow tract. What about the patient's symptomatology? Did you notice differences there? Dr. Milind Desai: There were significant improvement in patient symptomatology. More than 70% patients had a improvement in one NYHA class, 30% or thereabouts had a significant improvement in two NYHA class compared to placebo. So yes, there was a significant improvement in their functional capacity. Dr. Greg Hundley: And then last question, hypertrophic cardiomyopathy. Were most of these patients, was this concentric? Was this asymmetric septal hypertrophy? What was the breakdown, if you will, of the morphology of the left ventricles? Dr. Milind Desai: The vast majority of the patients had asymmetric septal hypertrophy, the characteristic with dynamic outflow tract gradient. There were some patients, but the vast majority of them were asymmetric septal hypertrophy. Dr. Greg Hundley: Very nice. Well, listeners, we're going to turn to our associate editor, Dr. Mark Link. Mark, this really sounds striking, randomized clinical trial, patients needing septal reduction therapy. They're randomized. The group randomized to mavacampten has marked reductions in left ventricular outflow tract gradient, symptomatology, and so much so that they no longer met the criteria for septal reduction therapy. I know you have a lot of papers come across your desk. Can you help us put what seemingly are exciting results into the context of other studies pertaining to mavacampten as well as treatment for patients with symptomatic hypertrophic cardiomyopathy? Dr. Mark Link: Yeah. There are very few randomized studies in patients with hypertrophic cardiomyopathy, probably only two that I know of. And mavacampten is a very exciting new drug that's a novel drug, a novel mechanism and has the potential to really improve life for our patients with hypertrophic cardiomyopathy. So this is a longer term study of mavacampten that's ever been published. So yeah, it was very exciting for us to look at this data to see how the patients did and we were very, very pleased to publish this paper. Dr. Greg Hundley: Very nice. So maybe, Milind, turn this back to you. What do you think are some of the next studies that'll be performed really in this arena of research? Dr. Milind Desai: Yes. Obviously, as Mark pointed out, this was one of the longest term studies, but we need to do a lot longer. So long term extension studies are ongoing. We should be evaluating one year outcomes in this specific population as well as longer, number one. Number two, I think in the grand scheme of things, this is a brand new class. So overall it is obviously now FDA approved and post-marketing survey and analysis should help us see a signal in terms of outcomes, mortality, et cetera. In your sister journal Circulation Imaging, we have simultaneously also published that mavacampten is causing a significant improvement in the structural changes like diastolic dysfunction, like LV mass, LA volume index. So we need to see how that plays out. Another important piece is about 30% patients have non-obstructive hypertrophic cardiomyopathy and there's no real treatment for this group and there's no outflow tract obstruction to cure in this. So we have just recently launched and started to randomize ODYSSEY HCM trial, which is checking the role of mavacampten versus placebo in non-obstructive HCM group. And I am fortunate. So it's a multi-centered trial that is being led out of Cleveland Clinic. So more data in that exciting field. But overall, this entire field of hypertrophic cardiomyopathies is exploding with multiple randomized controlled trials. There's another drug that is being tested in phase three trials, cardiac myocin inhibition. So that story also remains to see how that plays out. So a lot of stuff that is happening in this space. And then now there's gene therapy emerging. Dr. Greg Hundley: Right. And Milind, since you have quite extensive experience here, for our listeners, what side effect profiles have you observed in some of these patients? And if someone is considering working with placing a patient on this therapy, what are some of the considerations that they should be thinking about? Dr. Milind Desai: So that's a very important question. So the drug, as you are aware, was approved by the FDA under the REMS or Risk Evaluation Mitigation Strategy program. So the fundamental thing is both the patient and the physician have to sign up for the REMS program. The biggest issue that FDA wants us to be careful about is this is a cardiac myosin inhibitor. So it means we have to be very careful about over inhibition of the cardiac myosin and a drop in ejection fraction and its downstream ramifications including heart failure. The other aspect is drug-drug interaction because of its pathway of metabolism. So these are the two key things we have to be on the careful about. Now you asked my clinical experience. So we have been prescribing this for almost six, seven months, and we have dozens of patients on this using the REMS strategy, careful echocardiographic monitoring and clinical decision making. So far, we have been very successfully able to navigate these patients without any major adverse events. And the vast majority of the patients, true to form as we have shown in the clinical trial, are doing very, very well in terms of their symptoms, their need for SRT, as well as their markers, including outflow tract gradient. Dr. Greg Hundley: Very nice. And Mark, turning to you from the perspective of an electrophysiologist, what potential future studies do you see forming in this space? Dr. Mark Link: Yeah, very similar to Milind. And I think the long term efficacy and safety really has to be looked at. There's a signal for potential harm in that the EF can drop, and Milind mentioned that too, that we have to learn how to deal with that. The way to prescribe it now, you have to be in a special program. You have to be trained, you have to agree to get echoes every three months, I believe it is, essentially for the rest of their life. So we need to see what happens long term with these drugs and we need to know how to dose them and how to do it safely. Dr. Greg Hundley: Very nice. So for our listeners, really a class of drugs that is emerging and at this time only under really strictly supervise protocols. Well, from the perspective of our listeners, we want to thank Dr. Milind Desai and our own associate editor, Dr. Mark Link, for bringing us this informative new early randomized trial study results indicating that in severely symptomatic patients with obstructive hypertrophic cardiomyopathy, 32 weeks of mavacampten treatment showed sustained reduction in the proportion proceeding to septal reduction therapy. Well, on behalf of Petter, Carolyn and myself, we want to wish you a great week and we will catch you next week on The Run. This program is copyright of the American Heart Association, 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Xuerong Wen, Associate Editor Sandeep Das, and Guest Host Mercedes Carnethon as they discuss the article "Comparative Effectiveness and Safety of Direct Oral Anticoagulants and Warfarin in Patients With Atrial Fibrillation and Chronic Liver Disease: A Nationwide Cohort Study." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass of the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor, Director of the Poly Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, I'm so excited about today's feature paper. It deals with the important condition where atrial fibrillation exists in patients with chronic liver disease and what do we do for anticoagulation in these patients. It's a comparative effectiveness and safety study of direct oral anticoagulants compared with warfarin in these patients. A huge, wonderful, important study that we're going to discuss. But before we get there, I'd like to tell you about some papers in this issue and I'd like you to tell me about some too. You got your coffee? Dr. Greg Hundley: Absolutely. Dr. Carolyn Lam: All right. I'll go first In this paper that describes a quantitative prognostic tool for the mitral valve prolapse spectrum and it's derived from the new mitral regurgitation international database quantitative or MIDA-Q registry, which enrolled more than 8,000 consecutive patients from North America, Europe, Middle East. And these were patients all diagnosed with isolated mitral valve prolapse or MVP in routine clinical practice of academic centers, all of which also did prospective degenerative mitral regurgitation quantification. The MIDA-Q score was calculated based on characteristics collected in routine practice combining the established MIDA score, which integrated guideline based markers of outcomes like age, New York Heart Association status, atrial fibrillation, LA size, pulmonary artery pressure left ventricular and systolic, I mentioned, and ejection fraction. Integrating that with scoring points based on the degenerative mitral regurgitation quantitation that is measuring effective regurgitant orifice and volume. Dr. Greg Hundley: Very interesting Carolyn. So a scoring system that combines clinical information with what we might assess with echocardiography like regurgitant volume or regurgitant orifice area. So how well did this mortality risk score perform? Dr. Carolyn Lam: So the new score was associated with an extreme range of predicted survival under medical management and that ranged from 97% to 5% at five years for the extreme score ranges. And it was strongly, independently and incrementally associated with long-term survival over all the markers of outcomes. So the authors concluded, and these by the way were authors led by Dr. Maurice Serrano from Mayo Clinic, Rochester, Minnesota. These authors concluded that the score should allow integrated risk assessment of patients with mitral valve prolapse to refine clinical decision making in routine practice and ultimately reduce degenerative mitral regurgitation under treatment. Dr. Greg Hundley: Wonderful description Carolyn. Well I'm going to switch to the world of electrophysiology, Carolyn. And so as you know, the Brugada syndrome is an inherited arrhythmia syndrome caused by loss of function variants in the cardiac sodium channel gene SCN5A and that occurs in about 20% of subjects. And these authors led by Dr. Dan Roden at Vanderbilt University School of Medicine identified a family with four individuals diagnosed with Brugada syndrome, harboring a rare missense variant in the cardiac transcription factor, TBX5, but no SCN5A variant. And upon identifying these individuals, their objective was to establish TBX5 as a causative gene in Brugada syndrome and to define the underlying mechanisms by which it would be operative. Dr. Carolyn Lam: Oh wow. So a new gene variant. So what was the relationship? Dr. Greg Hundley: Right Carolyn? So using induced pluripotent stem cell derived cardiomyocytes from members of the affected family, multiple electrophysiologic abnormalities were detected in these cardiomyocytes including decreased peak and enhanced late cardiac sodium current. In these cells these abnormalities were entirely corrected by CRISPR/Cas9 mediated editing of that TBX5 variant and transcriptional profiling and functional assays in unedited and edited pluripotent stem cell derived cardiomyocytes showed direct SCN5A down regulation caused decreased peak sodium current and that reduced PDGF receptor expression and blunted signal transduction to phosphoinositide-3-kinase. And interestingly, PDGF receptor blockade markedly prolonged normal induced pluripotent stem cell derived cardiomyocyte action potentials. And also Carolyn interestingly in this study they did a separate analysis. It reviewed plasma levels of PDGF in the Framingham Heart Study and they found that they were inversely correlated with the QT corrected interval. And so Carolyn, these results established decrease SCN5A transcription by the TBX5 variant as a cause of Brugada syndrome and also reveal a new general transcriptional mechanism of arrhythmogenesis of enhanced late sodium current caused by reduced PDGF receptor mediated phosphoinositide-3-kinase signaling. Dr. Carolyn Lam: Wow. Wow, that's significant. Thanks Greg. So this next paper is also really important and could change the practice in the field of cardiac resynchronization therapy or CRT. You see, it suggests that the practice of what we do now, which is combining right bundle branch block with intraventricular conduction delay patients into a single non-left bundle branch block category when we select patients for CRT, that this may not be the way to go. So let's go back a bit and remember that benefit from CRT varies with QRS characteristics and individual trials are actually underpowered to assess the benefit for relatively small subgroups. So the current authors led by Dr. Friedman from Duke University Hospital and colleagues, therefore performed a patient level meta-analysis of randomized trials of CRT to assess the relationship between QRS duration and morphology with outcomes. Dr. Greg Hundley: Very interesting Carolyn. So another wonderful paper from the world of electrophysiology in trying to understand optimal mechanisms to resynchronize the ventricle in patients with differing bundle branch blocks or intraventricular conduction delays. So what did they find? Dr. Carolyn Lam: They found that patients with intraventricular conduction delays and a QRS duration of 150 milliseconds or more, CRT was associated with lower rates of heart failure hospitalizations and all cause mortality. The magnitude of CRT benefit among these patients with the interventricular conduction delay of 150 milliseconds or more and those with the left bundle branch block of 150 milliseconds or more were similar. In contrast, there was no clear CRT benefit for patients with a right bundle branch block of any QRS duration, although the authors could not rule out the potential for benefit at a markedly prolonged QRS duration. So they concluded that the practice of combining right bundle branch block with intraventricular conduction delay patients into a single non-left bundle branch block category when we make patient selections for CRT is not supported by the current data. And in fact, patients with an intraventricular conduction delay of 150 milliseconds or more should be offered CRT as is done for patients with a left bundle branch block of 150 milliseconds or more. Dr. Greg Hundley: Wow, Carolyn, so really interesting point. No clear CRT benefit for patients with right bundle branch block regardless of the QRS duration. Well we've got some other articles in the issue. I'll describe a couple from the mail bag. There's a Research Letter from Professor Lassen entitled "Risk of Incident Thromboembolic and Ischemic Events Following COVID-19 Vaccination Compared with SARS-COV2 Infection." Also Bridget Kuhn has a wonderful Cardiology News piece entitled "Collaborative Care Model Helps Heart Failure Patients Meet End-of-Life Goals." Dr. Carolyn Lam: There's an exchange of letters between Doctors Donzelli and Hippisley-Cox regarding that risk of myocarditis after sequential doses of COVID-19 vaccine, there's an AHA Update by Dr. Churchwell on continuous Medicaid eligibility, the lessons from the pandemic. There's an On My Mind paper by Dr. Parkhomenko on Russia's war in Ukraine and cardiovascular healthcare. Wow, what an issue. Thanks so much, Greg. Shall we go on to the feature discussion? Dr. Greg Hundley: You bet. Dr. Mercedes Carnethon: Well welcome to this episode of Circulation on the Run podcast. I'm Mercedes Carnethon, associate editor of the journal Circulation and Professor and Vice Chair of Preventive Medicine at the Northwestern University Feinberg School of Medicine. I'm very excited to be here today with Xuerong Wen and Sandeep Das, my fellow associate editor here at Circulation to talk about a wonderful piece by Dr. Wen and colleagues from the University of Rhode Island. So welcome this morning Xuerong and thank you so much for sharing your important work with us. Dr. Xuerong Wen: Thank you Dr. Carnethon. It was great meeting you all and I'm the Associate Professor of Pharmacoepidemiology and Health Outcomes at the University of Rhode Island. I'm happy to introduce my study to everyone. Dr. Mercedes Carnethon: Well thank you so much and thank you as well Sandeep for identifying this fantastic article and bringing it forth. Dr. Sandeep Das: Thanks Mercedes. It's great to be with you. Dr. Mercedes Carnethon: Great. Well let's go ahead and get into it. There's so much here to talk about. So Dr. Wen and colleagues studied the comparative effectiveness and safety of direct oral anticoagulants or DOACs and warfarin in patients with atrial fibrillation and chronic liver disease. So this is such an important topic. Can you tell us a little bit about what your study found? Dr. Xuerong Wen: So our study is a comparative effectiveness and the safety analysis using a national health administrative data from private health plans. So we compared the risk of hospitalized ischemic stroke, systemic embolism and major bleeding between DOACs and warfarin in patients with atrial fibrillation and chronic liver disease. So we also had to had compare to these primary outcomes between apixaban and rivaroxaban in the study population. So our studies show that among patients with atrial fibrillation and chronic liver disease, DOACs as a class was associated with lower risk of hospitalization of ischemic stroke and systemic embolism and major bleeding, compared with warfarin. And when compared risk outcomes between individuals apixaban has lower risks as compared to rivaroxaban. So that's our study results. Dr. Mercedes Carnethon: Well thank you so much. This seems like such an important question. We hear a lot about DOACs and some of their risks as well as their considerable benefits. I think what leaves me the most curious is why did you choose to pursue this question and in particular in patients with both atrial fibrillation and liver disease. So why was the intersection of these two particular conditions of interest to your study team? Dr. Xuerong Wen: That's a great question. So the liver actually plays a central role in both the synthesis of coagulation factors and the metabolism of anticoagulant drugs. And the clearance of the anticoagulants in liver ranges from 20% to 100% for DOACs and warfarin. So in clinical practice anticoagulation abnormalities and elevated risk of spontaneous or unprovoked venous thrombotic complications have been reported in patients with liver disease. While these patients with cirrhosis were excluded from the clinical trials of DOACs and also population based, the real world experience is very limited. So that is why we initiated this retrospective cohort study and based on the real world data in this specific population. Dr. Mercedes Carnethon: Oh, thank you so much for explaining that. I definitely learned a lot and really enjoyed reading the piece. I think it was very well organized and well written and I know that our readership will appreciate it. It obviously stood out to you as well, Sandeep. Can you tell me a little bit about why you thought that this would be an excellent piece for circulation? Dr. Sandeep Das: Yeah, absolutely. Thanks for the question. So in the broad field of what we call observational comparative effectiveness research, so basically that's using large observational data sets to try to answer important clinical questions and it's a really challenging thing to do. I mean we're all very familiar with the idea of using randomized trials to assess important clinical questions because of the structure of that design allows you to mitigate some of the effects of confounding. Here, it has to be done analytically. So what's the important factor that really drives you towards a great observational comparative effectiveness piece? So first the clinical importance. I feel a little guilty because I'm old enough to remember when warfarin was the only option available, but really as a clinician, or every patient, I really prefer DOACs over warfarin just for ease of use and lifestyle. So there's a huge sort of importance to the question. Second, the patients with chronic liver disease were excluded from the larger RCTs and the DOAC trials. So really we don't have the answer to the question already. It's an important question. Obviously the bleeding risk is tied up with the liver, warfarin directly antagonizes vitamin K, so there's real questions about safety and so this is the perfect storm and then on top of it was a really well done and well executed study. So when this came across my desk, the very first thing I thought was not, "Is this something that we're interested?" But rather, "How do we make it better? How do we make it more useful to the reader?" This had me from hello. Dr. Mercedes Carnethon: Well thanks so much. We rarely have the opportunity when we read an article to be able to ask the authors questions. So Sandeep, I know that you had mentioned that you had some follow up questions as well. Dr. Sandeep Das: Yeah. So the real thought that I have then is would you argue based on this that we know enough that we should change our practice? And that do you feel comfortable advocating that people now prescribe DOACs to these patients? Dr. Xuerong Wen: I would say yes. Okay. Although this is not a clinical trial, but our study is actually systematically compare the effectiveness and safety between DOAC users and also the warfarin users. And if you look at our table one, we compare with so many variables between these two users and we use the propensity score adjustment and we after propensity score weighting and the two control group almost balanced. And I know right now FDA actually suggested that emulate the trial using the large real world data to do the emulated trial. So our study actually conducted is based on the large population using large data and we use the propensity score weighting to control all this potential compounding factors. Although there are still some limitations in this study. I think we mentioned that in the discussion section and we discussed all potential compounding factors that still may exist. And also there are some misclassifications and out of all this limitations and we still found the two drugs performed differently in this specific population. So we feel that comfortable to say that a DOAC drug performs better than warfarin. And also I think based on other studies that based on the clinical trial in the general population, DOAC drug is performs much better than warfarin and considering that the clearance in liver for DOAC is less than warfarin. So plus all this information together, I think DOAC may be safer than wafarin in the patients with AF and chronic liver disease. Dr. Sandeep Das: Yeah, I would say that I agree that these data, even if you're skeptical about observational CT generally, which I admit that I tend to be, these are really reassuring data that at least the DOACs are... There's absolutely nothing that suggests that they're any worse than warfarin and all of the sort of soft indications for ease of use and patient happiness really would seem to favor DOACs. So I think this is the sort of rare observational CT paper that may actually change my practice. Dr. Mercedes Carnethon: I have a follow-up question, Xuerong, related to the design and as well your strategy to address differences between the groups. So inverse probability weighting is certainly a standard in the field to be able to manage differences between groups when you have a situation where can't, where it's not a randomized trial. Do you as well, and educate me, I admit I'm an epidemiologist whose methodological skills are sometimes challenged. Do you have the opportunity using this design and with inverse probability weighting to evaluate subgroup effects? So my specific question is were you able to determine whether or not these associations were similar based on age and gender in particular? Dr. Xuerong Wen: That's a great question. We did conducted a lot of subgroup study but not by age or gender. We conducted I think this study in a lot of subgroups using the propensity score weighting, but the subgroup that I think we did a subgroup like a patient with a different chronic liver disease. So that's what we did. And we also tested different methods inverse probability score weighting. So we did trimming and we used a different percentage of trimming and to see how that affect the study results. So we have done a lot of subgroup studies. We did not check the age and the gender, but that's a very good point. Maybe later, well I'll ask my student to do that. Dr. Mercedes Carnethon: Well, you're a good mentor. So I think that is a really certainly an appropriate approach. Sandeep, did you have additional questions? Dr. Sandeep Das: No, I wish I had thought of yours before you did. I think exactly the older age, women, racial ethnic groups that are underrepresented historically in trials. I think that that's really, again, the sweet spot of this observational research. We definitely, and NH definitely working on trying to increase enrollment of all these groups in our CTs. However, while we wait for that, I think that's exactly what we should be doing. Dr. Mercedes Carnethon: Well that's great. And Xuerong, you really alluded to really, I think what is one of my final questions related to what do you think based on what you have observed in this study, what do you see as the next steps in the research field for your team, your students, or other people who are carrying out this type of work? Dr. Xuerong Wen: Well, that's a great question. We currently have a couple of more manuscripts ongoing in this field, and we will continue conducting the comparative effectiveness and analysis to compare drugs head to head as well as developing and implementing new methodologies to this field. And we hope our study provides real world evidence for clinical decision making, prescribing anticoagulants to patients with atrial fibrillation and chronic liver disease. We also expect the physicians and researchers more and more value the real world data studies, especially when clinical trials are not feasible or ethical. Dr. Mercedes Carnethon: Well, thank you so much. That was such an excellent vision that you provided us with and we're just very grateful that you submitted this fantastic work to the journal Circulation. I know that our readers will enjoy really digging in. The podcast is meant as a teaser to bring you to the journal so that you can read about this wonderful work by Dr. Wen and colleagues. So again, thank you. I'm Mercedes Carnethon, joined with my associate editor partner here, Dr. Sandeep Das. And thank you very much for spending your time with us today, Dr. Wen. Dr. Xuerong Wen: Thanks for this great opportunity to disseminate my study with us, thank you. Dr. Sandeep Das: Thanks Mercedes. Dr. Mercedes Carnethon: Thank you for joining us for this episode of Circulation on the Run. Dr. Greg Hundley: This program is copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Jennifer Conway as she discusses the article "The Prevalence and Association of Exercise Test Abnormalities With Sudden Cardiac Death and Transplant-Free Survival in Childhood Hypertrophic Cardiomyopathy." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass of the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor and director of the Pauley Heart Center at VSU Health in Richmond, Virginia. Carolyn, wow. We're closing out the month of February, this is February 28th. And the feature discussion today, very interesting. So in patients with hypertrophic cardiomyopathy, we often see them as adults, and guidelines are very clear on how to manage them. What about patients' children that present with hypertrophic cardiomyopathy? How do we manage them? Should we do exercise testing? Well, to get the answers to some of those questions, you'll have to wait listeners to our feature discussion today. But first we're going to grab a cup of coffee and jump into some of the other articles in the issue. Carolyn, would you like to start? Dr. Carolyn Lam: I would love to. With this first paper, which is a preclinical study revealing a novel signaling axis in cardiorenal interaction. Dr. Greg Hundley: Wow. Pray tell. Dr. Carolyn Lam: I will. So this paper is from Dr. Molkentin and colleagues from University of Cincinnati. And using mouse models of ischemia reperfusion acute kidney injury and unilateral ureteral obstruction, these authors found that interleukin 33 release from the kidney endothelium during acute kidney injury communicates with the heart through the suppression of tumorigenicity 2 or ST2L receptor on cardiomyocytes. And that's where it causes hypertrophy, fibrosis, and loss of cardiac function. Mice lacking interleukin 33 or mice lacking the gene encoding this ST2L receptor on cardiomyocytes, but not endothelial cells or fibroblasts, were protected from acute kidney injury induced hypertrophy and cardiomyopathy. Indeed, inhibition of acute interleukin 33 release from the kidney after acute kidney injury with a monoclonal antibody prevented cardiomyopathy. So the interleukin 33 ST2L signaling axis is a novel potential therapeutic target to protect the heart during kidney injury. Dr. Greg Hundley: Wow, Carolyn, really interesting preclinical science relating acute kidney industry and cardiomyopathy. Well, I have another paper from the World of Preclinical Science. And, Carolyn, this pertains to the metalloprotease ADAMTS7, and it is a novel locus associated with human coronary atherosclerosis. ADAMTS7 deletion protects against atherosclerosis and vascular restenosis in rodents. Carolyn, these authors led by Professor Wei Kong from Peking University designed three potential vaccines consisting of distinct B-cell epitopic peptides derived from ADAMTS7 and conjugated with the carrier protein KLH as well as aluminum hydroxide as an adjuvant. And they tested the efficacy of the vaccines to evaluate coronary intimal hyperplasia in mirroring wire models and after stent implantation in porcine models. Dr. Carolyn Lam: Oh, wow. So a vaccine against atherosclerosis? Cool. Dr. Greg Hundley: Yeah, it is really a vaccine concept against restenosis. Carolyn, this peptide vaccine against metalloproteinase ADAMTS7 efficiently mitigated atherosclerosis in vaccinated hyperlipidemic mice without lowering lipid levels and impeded intimal hyperplasia in both the murine wired injured arteries and the swine stented coronary arteries without any significant immune related organ injuries. Carolyn, the clinical implications are that the vaccine against the metalloproteinase ADAMTS7 is a novel atherosclerosis vaccine, mainly targeting vascular remodeling, thereby also alleviating instent restenosis. And perhaps in the future the application of this vaccine would be a complimentary therapeutic avenue to current lipid loading strategies for atherosclerotic disease. And this is nicely followed by an editorial from Professors Heribert Schunkert and Thorsten Kessler. Dr. Carolyn Lam: Cool, thanks, Greg. Well, this next paper asks the question that if coronary artery calcium can be identified on non-gated chest CTs, can this finding be effectively incorporated into care with the help of AI? So the Notify One was a randomized quality improvement project in the Stanford healthcare system. Patients without known atherosclerotic cardiovascular disease or a prior statin prescription were screened for coronary arterial calcium on a prior nongated chest CT from 2014 to 2019 using a validated deep learning algorithm with radiologist confirmation. Patients with incidental coronary artery calcium were randomized to notification of the primary care clinician and patient versus usual care. Notification included a patient specific image of coronary artery calcium and guideline recommendations regarding statin use. And the primary outcome was statin prescription within six months. Dr. Greg Hundley: Really interesting, Carolyn. So coronary artery calcium observed when a patient might happen to come in for another chest CT scan or actually randomizing a patient population to being notified and maybe doctors act on it versus not. So what did they find? Dr. Carolyn Lam: Yep, beautifully summarized. And this is from Dr. Sandhu and colleagues from Stanford University. And what they found was among more than 2000 patients who met initial and clinical inclusion criteria, coronary artery calcium was identified by the algorithm in 424 patients and confirmed by a radiologist in 89% who were randomized to notification or usual care. At six months, the statin prescription rate was 51% in the notification arm versus 7% with usual care. Thus, opportunistic coronary artery calcium screening of prior nongated chest CTs followed by clinician and patient notification led to a significant increase in statin prescriptions. Further research is of course needed to determine whether this approach can actually reduce atherosclerotic cardiovascular disease events. This is discussed in an editorial by Doctors Joshi, Nasser, and Navar. Dr. Greg Hundley: Wow, Carolyn, you know, this all fits with behavioral science. When we see something, then often we change our behavior much more readily. And so, gosh, boy, just a perfect example of that in this last paper. Well, there's some other articles in the issue, and I see again, just as it was last week, you've got a whole list here to describe. Dr. Carolyn Lam: Oh, you bet Greg. First, there's an exchange of letters between Doctors Du and Lee on physical activity has no significant association with stroke. There's a primer by Dr. Leyva on “Declining Risk of Sudden Cardiac Death in Heart Failures, Is that a Fact or a Myth?” There's a Research Letter by Dr. Soehnlein on “Time Restricted Feeding Enhances Early Atherosclerosis in Hypercholesterolemic Mice.” There's also Highlights from the Circulation Family of Journals by Molly Robbins. The characteristics of patients with recurrent sudden cardiac death are described in circulation arrhythmia and electrophysiology. A proof of principle gene therapy for correction of long QT two and short QT one syndromes is presented in circulation, genomic and precision medicine. The impact of food insecurity on heart failure mortality is reported in circulation heart failure. The associations of hypertension and hypertension treatment with differences in sexual identities are presented in circulation, cardiovascular quality and outcomes. A multi-modality imaging and biomarker strategy to detect early decompensation with chronic aortic regurgitation is reported in circulation cardiovascular imaging, and an analysis of revascularization at the time of TAVR on cardiovascular outcomes is reported in circulation cardiovascular interventions. Finally, that's a Perspective piece by Dr. Turer on cardiac myosin inhibitors unlocking potential to improve treatment in hypertrophic cardiomyopathy. Dr. Greg Hundley: Wow, Carolyn, just another issue that's so rich with both preclinical and clinical science. Well, how about we get off to that feature discussion and learn more about management of children and young adults with hypertrophic cardiomyopathy? Dr. Carolyn Lam: So important. Let's go. Dr. Greg Hundley: Welcome listeners to this February 28th feature discussion where we're going to work into the world of hypertrophic cardiomyopathy in children. And we have with us today Dr. Jennifer Conway from Stollery Children's Hospital in Edmonton, Alberta. Welcome Jennifer. And maybe Jennifer, let's start off, could you describe for us some of the background information that went into the preparation of your study, and what was the hypothesis that you wanted to address? Dr. Jennifer Conway: Sure. And I would just like to start by thank you for inviting us to really present the information from our paper. We think it's a very exciting paper and are excited to share our results. When you think about hypertrophic cardiomyopathy in children, a lot of the information in the past has really been extrapolated from adults. And we know from the recent 2020 guidelines that exercise testing is really no longer part of risk stratification for adults. It's mostly used to look at functional outcomes and really when assessing patients more for heart failure related symptoms. So we wanted to see whether or not exercise testing in children had a different role because we know the recent risk stratifying calculators such as the primacy calculator that's come from this cohort of patients or HCM risk kids, has different risk factors that have been identified for sudden events, for instance, than in the adult population. And that's really kind of sparked us to see, well, maybe exercise has a different role in children than it does in adults. Dr. Greg Hundley: And so we wanted to investigate the role of exercise testing in children with hypertrophic cardiomyopathy. So how did you arrange your study design, and what was your study population? Dr. Jennifer Conway: This is an international cohort of 20 centers from the US, Canada, and Australia. And it's an observational cohort, and there is over 724 patients' information that has been collected within this cohort of patients. And for this particular study, 630 of them had an exercise test and therefore were included in the study to look at. Dr. Greg Hundley: And in the study population, I know it's a pediatric population, what was the age range? Dr. Jennifer Conway: The average range was about 13 years old with probably the youngest being around eight because that's really where you can do an exercise test with and that's up to 18 years of age. So that's kind of the general age range of patients. Dr. Greg Hundley: And of these pediatric populations, what percentage were, I guess, boys versus girls? Dr. Jennifer Conway: Yeah, so just over 75% were males within this study population. Dr. Greg Hundley: Okay. And then now Jennifer, can you describe for us your study results? Dr. Jennifer Conway: Sure. I think the first main result is that we can really think about what we defined as an abnormal exercise test so maybe we'll start with that and kind of explain our findings there. So abnormal exercise test in this study was really a threefold one if you had an abnormal blood pressure response. The other one is if you had ventricular ectopy or if you had ST-T wave changes, which we described as ischemia. And so taking those three together, about 28% of our pediatric patients had an abnormal finding on their exercise test. So that's kind of the first main finding. So then we took those abnormal exercise patients and compared those with a normal exercise test to try to look for outcomes. And the two outcomes that we mainly focused on all cause mortality and transplantation is one outcome and the other one was sudden cardiac death events. So when we looked at the five-year freedom for all cause mortality and transplant, we found that those who had an abnormal exercise test had a lower five-year freedom from all cause mortality and transplantation. And when we sub-analyzed the different abnormalities in the exercise test, we found that ischemia and an abnormal blood pressure response were both associated with kind of a higher risk of mortality and transplantation. And then when we went on to look at sudden cardiac death events, there was really no difference seen between those with an abnormal or normal exercise test in terms of sudden cardiac death events. But when we looked at the individual factors once again exercise induced ischemia was associated with a lower freedom from a sudden cardiac death event. Dr. Greg Hundley: Jennifer, frequently in adults we're often examining with exercise how the intracavitary or left ventricular outflow tract gradient may change with exercise. What did you find in children in regards to that parameter? Dr. Jennifer Conway: Yeah, so we couldn't actually study that because this was a compilation of different types of exercise tests. So not everybody at each institution did the same form of exercise tests. So some patients had an exercise echo, some had a CPET test, and some had an exercise stress test. And so we took the common parameters from all of those to study, so we weren't specifically able to look at LV outflow tract gradients for instance. Dr. Greg Hundley: Jennifer, as a pediatrician managing a patient with hypertrophic cardiomyopathy, how do we use the results of your study to influence how we might manage patients moving forward? Dr. Jennifer Conway: I think this is an excellent question, and there's probably really two things that we can think about. The first is, what is the role of exercise testing in pediatrics? And just as we're starting to discover what our risk factors are for sudden cardiac death events, I think we have to do a little bit more to discover what our role is truly going to be with exercise test. So one of the things that we're doing as part of the primacy group is trying to decide is if we add exercise testing abnormalities to the already developed primacy calculator, does it change its power at all? That's one of the things kind of for the future to see with the current kind of sudden death risk factor calculators, can exercise, add to them? The second thing is I think that there is probably a role in exercise testing in general with patients that you see in your clinic to look at these predictive outcomes, and that is not standard across centers. We know that because not everybody in this cohort had an exercise test. I think there are some higher risk patients that likely are not suitable for exercise tests, but I think a majority of the patients that we see likely can undergo exercise testing. And although it's not published in this paper, of the 630 patients, there's only one patient who had a kind of aborted arrest during the exercise test. And that patient was a higher risk patient who had a previous reported aborted arrest. And this actually corresponds with two other papers in the literature, one from CHOP in Boston where it's a very low event rate when exercise testing is done in a controlled environment with professionals around and have a lab set up to specifically do that. The other aspect of this I think is that as we're starting to understand hypertrophic cardiomyopathy in general better, I think using exercise tests to try to help design exercise interventions is going to be important. Another study that I'm doing that's not part of this is looking at the cardiovascular health of children with hypertrophic cardiomyopathy across Canada. And we are finding that there's a high level of obesity, sedentary lifestyle, high lipid profiles for instance, all of which put people at risk for cardiovascular disease as adults. And so I think as we're getting more comfortable potentially with looking at exercise prescriptions for hypertrophic cardiomyopathy patients and understanding risks a bit better, then exercise testings going to be a key in trying to design maybe some of that programming for patients. Dr. Greg Hundley: Wow, Jennifer, just a beautiful explanation of where we need to move with your research results in the future. One thing that kind of caught my attention as you were speaking, really safety. So for all our listeners, in terms of exercising children with this condition or young adults, would you recommend a specialized center or what would you describe in that, at least in terms of safety precautions? Dr. Jennifer Conway: Well, if you look at all the... There's not a lot of studies that have been published, but the ones that have, they're in a lab that commonly exercises children. They have protocols of who they will exercise and who they won't and when you would stop an exercise test. For instance, the paper from CHOP nicely describes how they approach the exercise in hypertrophic cardiomyopathy, and they have clear guidelines of when they stop testing. So in their 140 patients, for instance, they stop testing in two patients, one who had, I think ST segment changes and the other one who developed some ventricular ectopy. I think it needs to be in a controlled environment where you have safety measures in place and you have guidelines to direct you in terms of if this happens, this is the response to that. I think that's all very important when you're kind of thinking about exercising what has been deemed as higher risk patients. Dr. Greg Hundley: Very nice. Well, listeners, we want to thank Dr. Jennifer Conway from Stollery Children's Hospital in Edmonton, Alberta for sharing with us these really interesting results, highlighting that exercise abnormalities are common in childhood hypertrophic cardiomyopathy, and an abnormal exercise test was independently associated with lower transplant free survival especially in those with ischemic or abnormal blood pressure responses during that exercise testing. Well, on behalf of Peter, Carolyn and myself, we want to wish you a great week, and we will catch you next week on The Run. This program is copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Amil Shah and Associate Editor Ntobeko Ntusi as they discuss the article "Stages of Valvular Heart Disease Among Older Adults in the Community: The Atherosclerosis Risk in Communities Study." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor, Director at the Pauley Heart Center at VCU Health in Richmond, Virginia. Carolyn, this week's feature, very interesting. Many times in older individuals we understand how to manage severe valvular heart disease, for example, severe aortic stenosis. But do we really know how to manage individuals with mild valvular heart disease, for example, mild mitral regurgitation or aortic valve sclerosis? Well, our feature today will address that issue. And so, listeners, grab a cup of coffee. We're going to go through some of the other articles in the issue first, and then we'll get to that really interesting, very practical feature discussion. Well Carolyn, now that I've got my cup of coffee, this paper's from your group. And I'm going to ask you, Carolyn, as if it was a feature discussion, what was the background information that went into this and what was the hypothesis that you wanted to address? Dr. Carolyn Lam: Oh, it's great because it's at least not a Carolyn quiz, so I'm very happy to talk to you about it. Sex differences, as you know, it's a passion of mine. And in response to heart failure pharmacotherapies, in particular, we know that there are sex differences, wherein women appear to benefit from newer hormonal modulators across a wider heart failure ejection fraction range compared to men. And this was particularly evident in the Paragon heart failure trial of Arne versus Valsartan. However, whether these considerations also apply to the sodium-glucose Cotransporter 2 inhibitors or SGLT 2 inhibitors, remains unclear. So along with the groups from the DAPA-HF and DELIVER trial, we therefore examine and assess the impact of sex on the efficacy and safety of dapagliflozin in a pre-specified pooled analysis of these trials. Dr. Greg Hundley: Very interesting, Carolyn. So, differences between men and women and evaluation of efficacy of SGLT 2 inhibitors. So what did you find? Dr. Carolyn Lam: In essence, women and men derived similar benefits from dapagliflozin for both the primary outcome of worsening heart failure or cardiovascular death. And for secondary outcomes, including improvement in health status across the full spectrum of ejection fraction in heart failure. Dapagliflozin was also safe and well tolerated in both sexes. So these findings are consistent with other SGLT 2 inhibitors and suggest a class effect. And in fact, this is very, very nicely discussed in an accompanying editorial by Dr. Ileana Piña. Dr. Greg Hundley: Ah, very nice, Carolyn. Well, my first study here comes from the world of preclinical science. And Carolyn, this study assesses the role of epsins in modulating endothelial to mesenchymal transition in atherosclerosis. So Carolyn, you may ask what are epsins? Well, epsins are ubiquitously expressed adapter proteins involved in the regulation of endocytosis. And then Carolyn, there's a second process addressed in this study. And Carolyn, it is known that chronic vascular inflammation, a hallmark of atherosclerosis, induces a process called endothelial to mesenchymal transition. And during endothelial to mesenchymal transition, the transition of non-smooth muscle cell-derived cells that are capable of maintaining indices of atherosclerotic lesion stability are lost. And this allows atherosclerosis to progress to a more advanced stage. So Carolyn, in this study led by Dr. Hong Chen, from Boston Children's Hospital, these authors wanted to know if impacting epsins could reduce endocytosis and thereby modify endothelial to mesenchymal transition and attenuate atherosclerosis progression. Dr. Carolyn Lam: Sounds like an important concept to address in the progression of atherosclerosis. So what did they find, Greg? Dr. Greg Hundley: Right, Carolyn. So the authors found that epsins are required for endothelial to mesenchymal transition, and that the loss of these proteins in the endothelium reduces endothelial to mesenchymal transition by permitting sustained fibroblast growth factor receptor-1 protein, FGRF1, signaling by inhibiting the degradation of this receptor complex. They also demonstrate the efficacy of blocking epsin FGRF1 interactions specifically in atheromas using systemic administration of a targeted epsin UIM containing peptide to inhibit endothelial to mesenchymal transition and atherosclerosis progression in APO deficient and PCSK9 mutant viral induced atherosclerotic models. So Carolyn, in summary, these authors show that blocking these epsin FGRF1 interactions could provide a new approach to combat atherosclerosis progression. Dr. Carolyn Lam: Wow, Greg, thanks. Well, this next paper is an important preclinical paper showing that agents that induce senescence in cells of pulmonary vasculature can unexpectedly worsen rather than ameliorate pulmonary hypertension. So this paper is from Professor Serge Adnot and colleagues from Hospital Henri-Mondor in France. And they began by showing that in human lung tissues from pulmonary hypertension patients, about 30% of lung endothelial and smooth muscle cells have elevated P16, an observation recently also reported by others, as further evidence of senescence. Many of the cells with elevated P16 also had an increase in unrepaired DNA damage. They then used multiple senolytic strategies in several animal models to remove senescent cells and then found unexpectedly that eliminating senescent cells aggravated rather than suppressed pulmonary hypertension development. As models of pulmonary hypertension, the authors examined a number of animal models of pulmonary hypertension. That included rats exposed to chronic hypoxia, rats injected with the toxin monocrotaline, and rats injected with a VEGF receptor blocker prior to exposure to chronic hypoxia. As well as mice over-expressing the serotonin transporter in smooth muscle cells. And mice with P16 over-expression that develop pulmonary hypertension with age. So lots of animal models were tested and these animals also received the senolytic ABT 263 or FOX04-DRI, that would be expected to remove senolytic cells with equivalent results. Dr. Greg Hundley: Wow, Carolyn, so multiple animal models highlighting that senescent cells in the pulmonary vasculature can worsen rather than attenuate pulmonary hypertension. So what are the clinical implications of these models? Dr. Carolyn Lam: Well, this is discussed in a beautiful editorial by Dr. Rabinovitch that accompanies this paper. And quoting from that editorial, "The study is therefore extremely important in pointing out the potential overkill of senolytics in promoting rather than reversing pulmonary hypertension. The study also has particularly important translational implications as it indicates that the potential efficacy of an emerging therapy relies on the underlying disease mechanism and animal model use, the cell specificity dose, and root of administration." So lots of translational implications of this paper. Dr. Greg Hundley: Wow, Carolyn, so we've got some other articles in this issue and it looks like you've got a great review of those to describe. Dr. Carolyn Lam: Sure, I'd love to tell you about them. First there's a letter from Dr. Liao regarding the article, "Association Between Device Measured Physical Activity and Incident Heart Failure: A Prospective Cohort Study of the UK Biobank Participants." There's also a Cardiovascular Case Series by Dr. Ostrominski on "Pulling Out All The Stops: A Case of Progressive Dyspnea." In Cardiology News by Tracy Hampton, there's a story of scientists creating spatial map of cardiac remodeling after myocardial infarction, published in Nature. Loss of Y chromosome in myeloid cells promoting cardiac fibrosis, published in Science. And details behind the DNMT3A and TET2 mutations linking atherosclerosis. And that's published in Immunity. There's also a Perspective piece by Dr. Somers on “Whom to Screen and How to Screen for Obstructive Sleep Apnea in The Cardiology Clinic?” And a Research Letter by Dr. Felker on the clinical implications of negatively adjudicated heart failure events, data from the Victoria study. Dr. Greg Hundley: Wow, Carolyn, this issue, it's just packed with information. Well, how about we get on to that feature discussion? Dr. Carolyn Lam: Let's go. Thanks. Dr. Greg Hundley: Welcome listeners, to this feature discussion on this February 21, where we're going to delve into the world of valvular heart disease. And we have with us today Dr. Amil Shah from Brigham and Women's Hospital in Boston, Massachusetts, and our own associate editor, Dr. Ntobeko Ntusi from Cape Town in South Africa. Welcome gentlemen. Well Amil, we'll start with you. Could you describe for us some of the background information that really went into the preparation of your study and what was the hypothesis that you wanted to address? Dr. Amil Shah: Well, thanks very much, Greg, and let me start by thanking you and the circulation team for the interest in this paper and the opportunity to discuss it with you today. So I think in terms of background, we know that the prevalence and incidence of valvular heart disease increases with age, and that severe valvular heart disease is associated with substantial morbidity and mortality. Sub-severe valvular heart disease is, of course, even more common and has also been associated with worse cardiovascular outcomes. So I'm thinking of earlier studies that have associated even aortic sclerosis in the absence of stenosis with worse outcomes. Acknowledging the progressive nature of valvular heart disease, the ACCHA valve guidelines adopted this framework of valvular heart disease stages, where stage A was really defined as at risk for valvular dysfunction based on valve morphology in the absence of hemodynamic perturbation. Stage B is progressive valve dysfunctions. This is commonly what we would clinically consider mild or moderate valvular lesions. And then stage C, severe asymptomatic valve dysfunction. Stage D, severe symptomatic valve dysfunction. And we believe that looking at valvular heart disease in the context of these stages, as opposed to just as the hemodynamic severity of the lesion, can provide important insights into the burden of valvular heart disease. And especially sub-severe valvular heart disease in at-risk individuals, and in particular in older individuals. But the prevalence of these stages in the community and their progression over time really prior to this, to our knowledge, hasn't been described. And so really our aims and our hypotheses in this paper was to understand the prevalence of valvular heart stages amongst older adults. And really what we anticipate is that a large proportion of individuals in late life would have at least stage A, if not stage B, valvular heart disease. To describe the prognostic relevance of these stages, and particularly the sub-severe stages, and we anticipated that even stage A or stage B relative to no stage would be associated with worse outcomes, based on the prior literature. And finally, to characterize the rate of progression in late life. Dr. Greg Hundley: So rather than just the hemodynamic significance, it sounds like we're going to investigate the stages of valvular heart disease in an elderly population and associate that with prognosis. So how did we do that? What was your study design and can you describe for us also your study population? Dr. Amil Shah: Sure, of course. So we ended up using longitudinal data from a large cohort of older adults who are participating in the Atherosclerosis Risk in Communities, or ARIC study. So ARIC is an NHLBI funded longitudinal epidemiologic cohort. It's actually been following participants from four communities in the US since 1986. So Maryland, Mississippi, North Carolina, and Minnesota. Echocardiography was performed in just over 6,000. So 6,118 individuals are participants in 2011 to 2013. And at that time the mean age was 76. Just under 3,000 of those individuals underwent a repeat echocardiogram in 2018 to 2019. So that's a time elapse of about six and a half years, at which time the mean age was 81. So we're really looking at how things are changing between the ages of 76 to 81 years of age. We really focused on the mitral and aortic valves and determined or ascertained the stage of regurgitation or stenosis in those valves using a combination of quantitative and qualitative criteria based on the study echocardiograms, which are all read and interpreted centrally. And of course, each valve gets its own stage. And so for the purposes of this paper, we classified individuals as an overall valvular heart disease stage based on whichever valve had the highest grade lesion. Dr. Greg Hundley: Very nice. So using the ARIC study and then following the stages. So describe for us, Amil, what were your study results? Dr. Amil Shah: So at the first assessment, so amongst these approximately 6,000 individuals who had imaging in 2011 and 2013, the prevalence of stage A valvular heart disease was about 39% of individuals. Stage B, which again would be progressive, was about 17% of individuals. And stage C or D, which is really severe valvular heart disease, which was just over 1% in this community based population. And again, another 1% had previously undergone valve replacement or repair. And not surprisingly, even amongst this older cohort, older age was associated with a higher prevalence of each one of these stages. Then over a median follow up of about six and a half years, we looked at the association of each one of these stages with incident cardiovascular events relative to that group of individuals who were free of valvular heart disease stage in this cohort. And in each one of these stages, including stage A, was associated with a higher risk of incident heart failure, incident atrial fibrillation, coronary heart disease, which is largely MI, and then all-cause mortality. And that was true after accounting for many of common cardiovascular risk factors we usually think about as being related to risk for these outcomes. Interestingly, there was not an association with incident stroke in this study, although I will say our numbers for incident events were modest. Dr. Greg Hundley: Now, did you find similar results for men and for women? Dr. Amil Shah: So these results were fairly consistent for men, for women. And then the other demographic subgroup we looked at is... One of the unique features of ARIC is that it is a biracial cohort. And so when we looked at demographic subgroups based on both gender and race group, these trends were similar. Dr. Greg Hundley: And I know, Amil, right at the beginning you were discussing the importance of the stages versus the hemodynamic consequences. Did you do any comparisons, for many of us that are following patients, for example, with aortic stenosis? Did you find a discrepancy between using the stage as the defining term for a patient as opposed to the hemodynamic significance of one of these valve lesions? Dr. Amil Shah: Yeah, that's an excellent question. And so I think the first point to make is the valvular heart disease stages, of course, that we are assigning are based on the highest stage lesion, and so, of the four lesions we assessed. And part of this is a little nuanced, I guess, based on how the guidelines have defined these stages. So interestingly, if you look at stage A valvular heart disease, the majority of those individuals are getting in due to mild mitral regurgitation, because mild mitral regurgitation is considered stage A. In contrast, if you look at stage B, the majority of those individuals are getting in because of mild aortic regurgitation, because mild AR is considered stage B. And then stage C/D is really driven by aortic stenosis, probably not surprisingly. So what we can do is look not only overall, but also by stage within lesion. And certainly for aortic stenosis and mitral regurgitation, which are the most common valvular lesions we encountered, we saw similar findings. For mitral stenosis we had very few cases. So I don't think we can really comment on that based on this study. And for aortic regurgitation, we largely had individuals with no regurgitation or mild regurgitation, only a few with moderate. So again, we're a little bit limited in commenting on that. Dr. Greg Hundley: Very nice. Well, thank you so much, Amil. And listeners, now we're going to turn to our associate editor, Dr. Ntobeko Ntusi from Cape Town, South Africa. Ntobeko, you have many papers that come across your desk. What intrigued you about this particular paper? Dr. Ntobeko Ntusi: Thanks, Greg. I'd like to start by congratulating Amil and his co-authors on this paper, which as an associate editor was an absolute pleasure to handle. And the reason why we liked it are two-fold. Firstly, it's a large study, simple science of over 6,000 people. Very well characterized cohort clinically. We also liked its prospective design, as well as the protocolized nature of the echocardiograms. We liked that there was a central facility for core reading of all of these echocardiograms. And the use of a well-validated system of categorizing valvular heart disease. And importantly, we also liked the fact that it is a very representative study in terms of ethnicity and sex. And for me, there were three important takeaway messages from this study which advance our concepts of valvular heart disease. The first is that we've known for a long time that most severe valvular heart disease is associated with poor outcomes. But for the first time, this study provides us with data that shows a clear created association between the valve stage and outcomes related to mortality incident at fila and incident AF. So this is a new contribution. The second important novel contribution from the study is the data they provided on disease progression between stages of valvular heart disease. And then thirdly, I really liked the figures, in particular figure three and figure four, which I think are going to be highly cited and used in many presentations. So figure three demonstrates the Kaplan-Meier curves and shows survival rates dependent on the stage of valvular heart disease. And figure four, beautiful alluvial plot showing disease progression. And for these reasons we thought this was a piece that we would like to include in Circulation. Thanks, Greg. Dr. Greg Hundley: Thanks so much, Ntobeko. Well Amil, based on all this work, where are you going next? What do you see as the next study to really be performed in this sphere of research? Dr. Amil Shah: So two major findings I think that may have downstream consequences for future studies, first relate to identifying a subgroup A. That these valvular heart disease stages progress fairly substantially over fairly limited periods of time in late life. And really identify older individuals with certainly stage B, but even stage A valvular heart disease as a group, not only that we should screen with follow up, as recommended by the guidelines when we do detect sub-severe valvular lesions. But also potentially for therapeutics to prevent progression as those become increasingly available. And so I think one place where this data may be very helpful is in thinking about at-risk groups to evaluate therapeutics in. I think the second place is this relationship of even stage A valvular heart disease with adverse outcomes, which I think suggests that when we see valve deformation on imaging, that is likely a marker of risks that we're not fully capturing using our other traditional cardiovascular risk factors. And potentially could begin to become incorporated into how we think about risk stratifying our patients. Dr. Greg Hundley: Very nice. Ntobeko, do you have anything to add? Dr. Ntobeko Ntusi: Indeed. So I think in terms of future directions, there are probably three questions that I think would be important in taking this work forward. The first one is that this is clearly a descriptive epidemiological study. And for me it would be interesting to look at some of the mechanisms that underlie the adverse clinical outcomes associated with different stages of valvular heart disease. Two, the follow-up is relatively short and I think that it will be interesting as these individuals continue to be followed up long term, to see how these observations are either strengthened or evolve over time. And then finally, which is probably not going to be possible with the ARIC cohort. I think it would be useful to also look at rates of disease progression, but also the associations with outcomes in a younger cohort. And so for me, those would be interesting future ways of taking this work forward in the future. Thank you, Greg. Dr. Greg Hundley: Very nice. Well, listeners, we're going to wrap up and we want to thank Dr. Amil Shah from Brigham and Women's Hospital in Boston, Massachusetts, and our associate editor, Dr. Ntobeko Ntusi from Cape Town in South Africa, for bringing us this study highlighting that subclinical valvular heart disease is common in older adults with 39% at risk for stage A, and 17% with progressive valvular heart disease, or stage B. And they are independently associated with the risk of incident cardiovascular events. Well, on behalf of Peder, Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. This program is copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
Please join author Petr Ostadal and Associate Editor Dharam Kumbhani as they discuss the article "Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock: Results of the ECMO-CS Randomized Clinical Trial." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Peder Myhre: And I'm Dr. Peder Myhre, social media editor from Akershus University Hospital and University of Oslo in Norway. And today Carolyn will have such an interesting feature discussion. We are going to look into the use of ECMO to treat patients with cardiogenic shock, the results of the ECMO-CS randomized clinical trial. Isn't that interesting? Dr. Carolyn Lam: Awesome. Can't wait. But I suppose you're going to tell us about some papers in the issue first. I'm getting my coffee. Dr. Peder Myhre: Yeah, go ahead. Because first we're going to talk about a very interesting paper that relates to diabetes and the progression of coronary artery disease. So as you know, Carolyn, diabetes remains associated with an increased risk of cardiovascular morbidity and mortality. And although the absolute risk difference between patients with and without diabetes have declined over the past 20 years, we still don't know what is the diabetes associated differences in coronary plaque morphology and lipid content. Dr. Carolyn Lam: It's true. That's a very interesting question. And will you tell us more? Dr. Peder Myhre: Yeah. So the investigators in the prospect two study who enrolled patients exclusively from Denmark, Norway in Sweden who presented with biomarker positive MI and assessed both culprit lesions and untreated non-culprit lesions in these patients. And then they stratified the patients by diabetes status and examined with three vessel quantitative coronary angiography and near infrared spectroscopy and intravascular ultrasound imaging after successful percutaneous coronary intervention. Dr. Carolyn Lam: Okay, that's deep investigation. And what did they find? Dr. Peder Myhre: So diabetes was present in about 12% of patients and during a median or 3.7 year follow up, MACE occurred almost twice as free frequently in patients with versus without diabetes. And that was primarily due to an increased risk of MI related to culprit lesion stenosis and non-culprit relation related spontaneous MI. However, baseline prevalence of high-risk plaque characteristics was similar for patients with versus without diabetes, concerning culprit and the non-culprit lesions and in multi-variable models, diabetes was associated with MACE in lesions but not with prevalence of high-risk plaque characteristics. So Carolyn, the authors conclude that diabetes related plaque characteristics that might underlie the increased risk were not identified by multimodal imaging. Dr. Carolyn Lam: Oh, I just love studies like that so elegant with just a really, really intriguing results that make us ask more important questions. Love it. Thank you. Well, the next paper is also about myocardial infarction, but this time looking at the fibrotic remodeling after myocardial infarction because we know that MI induces a repair response that ultimately generates a stable fibrotic scar. And although the scar is important to prevent cardiac rupture, excessive pro-fibrotic response impairs optimal recovery because it promotes a development of non-contractual fibrotic areas. So would it be possible to regulate the expansion of cardiac fibroblast after MI through a paracrine action on the cardiac stromal cells? So the authors led by corresponding author Dr. Hulot from University of Paris performed a bioinformatic secretome analysis of cardiac stromal PW1 positive cells isolated from normal and post MI mouse hearts to identify novel secreted proteins. And they found that first cardiac PW1 positive stromal cells responded to myocardial infarction by secreting factors that promoted the proliferation and activation of resident fibroblasts and one such factor growth differentiation factor three or GDF3 was highly upregulated in the ischemic hearts and promoted a high induction of fibroblast proliferation via interaction with TGF beta receptors and activation of SMAD1/5 and SMAD2/3 signaling cascades. The upregulation of GDF3 was detected in the plasma of mice and humans following MI and high levels of plasma GDF3 in the days following MI predicted adverse outcomes measured six months later including cardiac dilation and limited recovery of contractile function in humans. Dr. Peder Myhre: Oh, that's so interesting. We already know GDF15 were very well, but now we hear about GDF3 in predicting fibrotic remodeling post myocardial infarction. So Carolyn, what are the clinical implications of these findings? Dr. Carolyn Lam: Exactly, Peder, in fact you said it. So the detection of high circulating GDF3 in plasma may serve as a novel biomarker of adverse fibrotic remodeling in heart tissue. That's one. And next the measurement of GDF3 plasma levels in the early post MI phase may allow for the identification of patients within an increased risk of severe myocardial fibrosis and heart failure and therefore could guide specific disease management. Dr. Peder Myhre: Thank you. That was an excellent summary of the paper, Carolyn. And now I'm going to look into a paper that relates to the important issue of arteriosclerosis following heart transplantation because as you know, transplant arteriosclerosis characterized by concentric and diffuse narrowing of vastly lumen is a major complication in long-term survivors of heart transplant patients. And increased lymph flow from donor heart to host lymph nodes has been reported to play a role in transplant arteriosclerosis. But how lymphangiogenesis affects this process is unknown. The authors of this paper, which comes to us from corresponding author Sue from Sejong University, transplanted vascular allografts between various combinations of mice including mice with severe combined immune deficiency and studied the lymphatic vessels within the grafted arteries. Dr. Carolyn Lam: Wow, that is really cool. Studying lymphatics and lymphangiogenesis in atherosclerosis. Interesting. What did they find, and what are the clinical implications? Dr. Peder Myhre: So Carolyn, lymphangiogenesis within allograft vessels began at the anastomotic sites and extended from preexisting lymphatic vessels in the host. Tertiary lymphatic organs were identified in transplanted arteries at the anastomotic site and lymphatic vessels expressing CCL21 were associated with these immune structures. Fibroblasts in the vascular allografts released VEGFC, which stimulated lymphangiogenesis into the grafts and inhibition of VEGFC signaling inhibited lymphangiogenesis, neointima formation and adventitial fibrosis of vascular allografts. And these studies identified VEGFC released from fibroblasts as signal stimulating lymphangiogenesis extending from the host into the vascular allografts. So, Carolyn, the authors conclude that the formation of lymphatic vessels play a key role in the immune response to vascular transplantation and inhibition of lymphangiogenesis may be a novel approach to prevent transplant atherosclerosis. Dr. Carolyn Lam: Wow, that is super interesting. Thanks, Peder. While also in this issue, there's an exchange of letters between Drs. Tanaka and Schulze regarding SGLT2 inhibitor treatment in acute decompensated heart failure. Why do we initiate it early? There's also a really nice On My Mind paper by Dr. Schiattarella on Cardiometabolic HFpEF. Is it the NASH of the heart? Dr. Peder Myhre: Oh, that's interesting. We also have some cardiology news by our own Bridget Kuehn entitled “No Benefit Seen for Nighttime Dosing Over Morning Dosing for Antihypertensive Medications.” And this is a summary of the time trial, which was presented at European Society of Cardiology Congress in 2022. And finally, Carolyn, we have a Research Letter entitled “Stepwise Generation of Human-Induced Pluripotent Stem Cell Derived Cardiac Parasites to Model Coronary Microvascular Dysfunction” by Dr. Joseph Wu from Stanford University School of Medicine. Dr. Carolyn Lam: While cool, Peder. But now I'm so excited to hear about the ECMO-CS randomized trial. Let's go. Dr. Greg Hundley: Welcome listeners to this February 7th feature discussion and we have with us today Dr. Petr Ostadal from Na Homolce Hospital in Prague in the Czech Republic and our own associate editor, Dr. Dharam Kumbhani from UT Southwestern in Dallas, Texas. Welcome, gentlemen. Well, Petr, we'll start with you. Can you describe for us some of the background information that really led you to perform this study, and what was the hypothesis that you wanted to address? Dr. Petr Ostadal: According to the current guidelines from the management for the management of cariogenic shock, it should be considered administration of inotropes and vasopressor for hemodynamic stabilization, or it may be considered administration of inotropes and vasopressors and it should be considered the use of short-term mechanical circulatory support. And the aim of the ECMO-CS trial was to compare early conservative therapy with inotropes and vasopressors and immediate implementation of ECMO in patients with the rapidly deteriorating or severe cardiogenic shock. The hypothesis of the ECMO-CS trial was that immediate implantation of ECMO in patients with cardiogenic shock and critical hemodynamic condition will be associated with improved outcomes. Dr. Greg Hundley: Very nice. Can you describe for us this study population and then also what study design did you use to address your hypothesis? Dr. Petr Ostadal: We try to select patients who can really profit from the early ECMO implantation, and we define two categories of patients. First category where the patients with rapidly deteriorating cardiogenic shock corresponding to current sky stage D or E. This patient should have evidence of left ventricle pump failure as left ventricle ejection fraction below 35% or ejection fraction 35 to 55 in case of severe mitral regurgitation or aortic stenosis. And this patient also should require a repeated both of vasopressors to maintain mean arterial pressure about 50 millimeters of mercury. The second category where the patients with severe cardiogenic shock corresponding to current sky stage D and this patient should have the criterion of a hemodynamic conditions which was cardiac index less than 2.2 or systemic blood pressure below 100 millimeters of mercury in both situation with higher doses of inotropes and vasopressors. And in case of a low systolic blood pressure, also the evidence of left ventricle pump failure based on ejection fractional below 35 or ejection fraction 35 to 55 in case of severe mitral regurgitation of aortic stenosis. The second criteria for the metabolic criteria, that was the evidence of tissue hypoperfusion and this was defined as a higher lactate above three millimeters per litter or low ScvO2 below 50%. And the third criterion was exclusion of hypovolemia, and this was based on central venous pressure or pulmonary artery wedge pressure. So this was the major inclusion criteria in the ECMO trial. The study population was not defined based on theology of cardiogenic shock, but just on severity of cardiogenic shock. Dr. Greg Hundley: Very nice. And so your design, did you have a one-to-one randomization, or how did that work? And then also how many subjects did you include in this important trial? Dr. Petr Ostadal: The patients were randomized in one-to-one ratio to immediate implementation of ECMO or to early conservative therapy. But it is important to point out that in the early conservative therapy downstream use of ECMO was allowed in case of further hemodynamic worsening defined as increase of what lactate by three millimeters per litter. We enrolled 122 patients, 61 were randomized to early ECMO and 61 to early conservative strategy. Five patients were excluded due to absence of informed consent and finally 58 patients were analyzed in the early ECMO or immediate ECMO arm and 59 patients were analyzed in the early conservative arm. Dr. Greg Hundley: Sounds great Petr. And then tell us and describe your study results. Dr. Petr Ostadal: The primary endpoint was composite of death from any cause, resuscitated circulatory RS and implementation of another mechanical circulatory support including ECMO in the early conservative arm at 30 days. And there was no difference in the primary endpoint with P 0.2221 and has a ratio of 0.72 with a 95% confidence in interval 0.46 to 1.12. There was also no difference in the incidence of death from any cause. 50% in the immediate ECMO arm and 28%, 47.5% in the early conservative arm. There was no difference in the incidence of resuscitated circulatory arrest, 10.3 in the immediate ECMO arm and 13.6 in the early conservative arm. Less patient required another mechanical circulatory support in the early ECMO arm through 17.2 in comparison with 42.4% in the early conservative arm and downstream ECMO was used in 39% of patients in the early conservative arm. Dr. Greg Hundley: Very nice. So similar results both immediately and then 30 days later for both arms. And I think that last point that you make is very interesting. 39% of the individuals randomized to the conservative arm went on to receive VA-ECMO. Well, listeners next, we're going to turn to one of our associate editors and Dharam, you have many papers that you see. How do we put the results that Petr has just described really in the context of management of shock and results that have been published previously? Dr. Dharam Kumbhani: Yeah, Greg, thank you. And Petr, thank you for this important paper and again, I'm really honored to be here on behalf of Circulation on the Run. So again, want to congratulate the authors for really an important study. I think in terms of context, what is really interesting is the use of ECMO, particularly VA-ECMO for patients with shock has really skyrocketed. And it is interesting that this expansion has occurred in the absence despite, I guess high quality clinical trials, this trial certainly fills an important void. Although it is a small patient population, it is randomized, it is a largest randomized trial to date on this important population. And so I think most of the studies that have been done so far have been done using observational data sets which have sort of inherent limitations. So I certainly want to congratulate you on trying to study this very challenging population because in sort of that acute setting, it's frequently very hard to get patients randomized. So just broadly in that context, I think at the same time this study does sort of pose some important questions and sort of perhaps leads, just given the limitations of the sample size does sort of leave a few unanswered questions. So one question I have is, Petr, in addition to the 40% crossover rate is obviously important as Greg pointed out. The other thing is it appears that the use of other mechanical support during the conduct of this trial was also close to 40%, about 42%. So pretty much everybody in the conservative arm ended up with some kind of mechanical support. Now, at least in the last few years, a concept that has gained a lot of traction is a concept of a shock team where a number of providers with particular expertise from different disciplines would get together and sort of decide next steps was a shock team sort of part of the decision-making, especially for the conservative arm. Dr. Petr Ostadal: Thank you for this question. The situation is maybe a little bit more simple in the Czech Republic here, the cardiologist are responsible for the acute cardiac care, usually competent and experience not only for the diagnosis and examinations and monitoring of patients in cardiogenic shock, but also experience in insertion and management of the mechanical circulatory support. So here this attending cardiologist competent to manage this patient from different sites from the manage not only the conservative therapy but also the mechanical circulatory support therapy in these patients. So in this respect, this is more simple situation in the Czech Republic. Dr. Dharam Kumbhani: I just had a very quick question about, and I don't know if you want to include this, but Petr, I was curious, were patients with cardiac arrest, I know you mentioned sky shocks in were patients with cardiac arrest on the field or in the hospital included? Dr. Petr Ostadal: Thank you for this excellent question. And in comparison, with other trials comparing the or focusing on patients with cardiogenic shock in the ECMO-CS trials, cardiac arrest survivors were excluded. And the reason was that the brain damage, which is the major cause of death in these patients cannot be influenced by ECMO insertion. And second, in majority of patients after cardiac arrest, if there is a presence of shock, there is frequently combined shock with important peripheral component. And again, it cannot be assumed that this peripheral component can be reversed by ECMO implantation. So in the ECMO-CS trial, the cardiac arrest survivors were excluded from that enrollment. Dr. Greg Hundley: Well, thank you so much Petr. Petr, what do you think is the next study to be performed really in this area of research? Dr. Petr Ostadal: I think that we are happy because several other clinical trials focusing on the mechanical circulatory support in patients with cardiogenic shock underway. And there are other trials focused on ECMO and trials a bit focused on combination of ECMO with balloon pump and trials focused on Impella. So I think in the very close time we will be able to see the results of these current running trials1. Dr. Greg Hundley: And Dharam, do you have anything to add? Dr. Dharam Kumbhani: No, I agree completely with Petr. I think this is a very exciting field. I know there's a lot of interest in doing well conducted clinical trials in this space. And so certainly, I think the future is bright for investigation in this field. Dr. Greg Hundley: Very nice. Well, listeners, we want to thank Dr. Petr Ostadal from Prague in the Czech Republic and our own associate editor, Dr. Dharam Kumbhani from Dallas, Texas for bringing us this study highlighting that immediate implementation of VA-ECMO in patients with rapidly deteriorating, or severe cardiogenic shock did not improve clinical outcomes compared to an early conservative strategy that permitted downstream use of VA-ECMO in the case when the patient's hemodynamic status worsened. Well, on behalf of Carolyn, and Peder, and myself, we want to wish you a great week and we will catch you next week on the run. This program is copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
Please join Guest Host Maryjane Farr, authors Sarah Franklin and Stavros G. Drakos, as well as Associate Editor Hesham Sadek as they discuss the article "Distinct Transcriptomic and Proteomic Profile Specifies Heart Failure Patients With Potential of Myocardial Recovery on Mechanical Unloading and Circulatory Support." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your cohosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center in Duke National University of Singapore. Dr. Peder Myhre: And I'm Dr. Peder Myhre, social media editor from Akershus University Hospital and University of Oslo. Dr. Carolyn Lam: Peder, today's featured paper is very, very important in the heart failure world. It is such a deep dive into the transcriptomic and proteomic profile that specifies heart failure and the potential of myocardial recovery with mechanical unloading and circulatory support. Dr. Peder Myhre: Can't wait for that feature discussion today, Carolyn. Dr. Carolyn Lam: But you have to wait because I insist on telling you about yet another really important paper, of course in my favorite subject, heart failure with preserved ejection fraction or HFpEF. Now you know that exercise intolerance is a defining characteristic of HFpEF and a marked rise in pulmonary capillary wedge pressure during exertion is pethepneumonic for HFpEF and it's thought to be a key cause of the exercise intolerance. Now if that is true, acutely lowering the wedge pressure should improve exercise capacity, right? Well, don't assume this because to test this hypothesis, authors led by corresponding author Dr. Ben Levine from UT Southwestern evaluated peak exercise capacity with and without nitroglycerin, which was used to acutely lower pulmonary capillary wedge pressure during exercise in patients with HFpEF. Dr. Peder Myhre: Oh, that's so cool. What an amazing research question and Carolyn, you're the best to summarize this. Please tell us what did they find? Dr. Carolyn Lam: Well, they studied 30 patients with HFpEF and get this. They underwent two bouts of upright seated cycle exercise dosed with sublingual nitroglycerin or a placebo every 15 minutes in a single blind randomized crossover design. So really well done. Wedge pressure, VO2 and cardiac output were assessed at rest with 20 watts exercise and at peak exercise during both the placebo and nitroglycerin conditions and the principle finding of the study (singing) acutely lowering pulmonary capillary wedge pressure during upright exercise with nitroglycerin in HFpEF did not improve peak exercise performance. So peak VO2 was practically identical with a 1% difference despite a 17% drop in peak wedge pressure. Peak cardiac output and peak peripheral oxygen extraction were unchanged, again, despite the drop in peak wedge pressure suggesting that oxygen delivery and utilization were unaffected. Exercise performance variables including peak wattage, peak ventilation and peak RER were unchanged, suggesting that again, reductions in peak wedge were insufficient to improve exercise tolerance. All these results suggest acute reductions in wedge pressure are insufficient to improve exercise capacity and provide convincing evidence that a high wedge during exercise by itself is an epiphenomenon perhaps rather than a primary limiting factor for exercise performance in patients with HFpEF. Now of course this is incredibly interesting contrary to hypothesis and so please read the paper. The discussion is very rich. Dr. Peder Myhre: Oh wow, Carolyn. That is such a great paper. I can't wait to pick it up and read it from start to finish and now Carolyn, we're going to look into research within cardiovascular disease from COVID-19 and we have learned so much and so quickly about COVID-19 and its effects on the heart and we have really come a long way from the first case reports reported in the beginning of the pandemic and this paper, which comes to us from corresponding author Professor JP Greenwood, really adds important knowledge to this field. The COVID heart study was a prospective longitudinal multi-center observational cohort study of patients hospitalized with COVID-19 and at elevated serum troponin levels across 25 hospitals in the UK and these investigators aim to characterize myocardial injury, its association and sequela in convalescent patients following hospitalization with COVID-19 utilizing appropriately matched contemporary controls. Dr. Carolyn Lam: Ooh, important stuff. So what did they find? Dr. Peder Myhre: So these authors included in total 519 patients comprising 342 patients with COVID-19 and an elevated troponin, 64 patients with COVID-19 and a normal troponin and 113 age and comorbidity matched controls without COVID-19 and the frequency of any heart abnormality defined as left or right ventricular impairment, scar or pericardial disease was two full greater in patients with COVID positive and troponin positive, so 61% compared to the control groups and that is 36% for COVID positive and troponin negative and 31% for COVID negative and comorbidity positive and the myocardial injury pattern was different for these patients with COVID and an elevated troponin more likely than controls to have infarction and micro infarction. But there was no difference in non-ischemic scar and using the late MRI criteria, the prevalence of probable recent myocarditis was almost 7% for those with COVID and elevated troponin compared to only 2% for the controls without COVID-19 and myocardial scar is but not prior COVID-19 infection or troponin was an independent predictor of MACE. So Carolyn, these authors discussed their findings in light of previously reported studies and these authors identified a lower prevalence of probable recent myocarditis than previously described and a higher proportion of myocardial infarction and this newly described pattern of micro infarction following COVID-19 and Carolyn, there is a brilliant editorial really summarizing this by Dr. Stuber and Baggish entitled "Acute Myocardial Injury in the COVID Heart Study Emphasizing Scars While Reassuring Scarce." I really recommend everyone to pick this up and read the editorial as well. Dr. Carolyn Lam: Very clever title. Thank you. For the last original paper in today's issue, it focuses on the crosstalk between sterile metabolism and inflammatory pathways, which have been demonstrated to significantly impact the development of atherosclerosis. Authors today are featuring and focusing on 25 hydroxy cholesterol, which is produced as an oxidation product of cholesterol and belongs to a family of bioactive cholesterol derivatives produced by cells in response to fluctuating cholesterol levels and immune activation. So these authors with co-corresponding authors, Dr. Suárez and Fernández-Hernando from Yale University School of Medicine, they showed beautifully that first, 25 hydroxy cholesterol accumulates in human coronary atherosclerosis. Next, that 25 hydroxy cholesterol produced by macrophages accelerated atherosclerosis progression and promoted plaque instability by promoting the inflammatory response in macrophages and also via paracrine actions on smooth muscle cell migratory responses. Dr. Peder Myhre: Wow, that is so interesting, Carolyn. What are the therapeutic implications of these findings? Dr. Carolyn Lam: Yes, I'm glad you asked because it was summarizing a lot of work in those findings with the very important implications that inhibition of 25 hydroxy cholesterol production might therefore delay atherosclerosis progression and promote plaque stability. So this study actually opens a door to explore the role of 25 hydroxy cholesterol as a target to control inflammation and plaque stability in human atherosclerosis. Dr. Peder Myhre: Oh, that is so important. Thank you so much and there is more in this issue as well, Carolyn. We have another issue of Circulation Global Rounds and this time we're going to France in a paper written by Dr. Danchin and Bouleti. We also have an exchange of letters by Dr. Yang and Dr. Schultze regarding the article, "Deep Lipidomics in Human Plasma: Cardiometabolic Disease Risk and Effect of Dietary Fat Modulation" and an ECG Challenge by Drs. Manickavasagam, Dar and Jacob entitled "Syncope After Transcatheter Aortic Valve Implantation: Pace or Not." Dr. Carolyn Lam: Interesting. There's a Frontiers paper also by Dr. Dimopoulos on “Cardiovascular Complications of Down Syndrome: Scoping Review and Expert Consensus,” a Research Letter by Dr. Kimenai on the impact of patient selection on performance of an early rule out pathway for myocardial infarction from research to the real world. Nice. Well let's carry on to that feature discussion on heart failure, transcriptomics and proteomic, shall we? Dr. Peder Myhre: Can't wait. Dr. Maryjane Farr: Welcome everybody to Circulation on the Run. We are so pleased to be talking with Dr. Stavros Drakos and Dr. Sarah Franklin from the University of Utah. My name is Maryjane Farr and I am the heart failure section chief at UT Southwestern and Digital Strategies editor for circulation. Myself and Hesham Sadek will be talking with them about their new paper and circulation called "Distinct Transcriptomic and Proteomic Profile Specifies Heart Failure Patients with Potential of Myocardial Recovery Upon Mechanical Unloading and Circulatory Support." Just briefly, Dr. Stavros Drakos is the director of cardiovascular research for the division of cardiology at Utah and co-director of the Heart Failure Mechanical Circulatory Support and Heart Transplant Program. Dr. Sarah Franklin is associate professor of medicine at the University of Utah whose lab has a specific expertise in the applications of proteomics to heart disease. Welcome, Stavros and Sarah. Dr. Sarah Franklin: Thank you. Dr. Stavros Drakos: Thank you. Thank you for having us. Dr. Maryjane Farr: This paper is exciting for clinicians. It's exciting for translational scientists. Hesham, why don't you start digging into this paper and tell us one or then the other of you tell us what this paper is about, what's the background and let's get into the science. Let's go there and then we'll pull back and look at some of the big picture stuff. Hesham. Hesham Sadek: Well, thank you. So I've been fascinated by the field of cardiac recovery for some time now and obviously Stavros is as an expert and one of the leaders of that field and what struck me about this is that we are starting to see some distinct molecular signature of patients that can experience recovery as opposed to patients undergoing the same procedures with the same profile that do not manifest evidence of myocardial recovery and specifically, the study was conducted very rigorously and the signature was very clear in that they saw primarily interest for someone like me who's interested in cardiac regeneration, a signature of cell cycle in the patients that experience recovery as well as ECM signature which could suggest reverse remodeling and also there's some evidence that ECM might impact cardiomyocyte and myocardial regeneration. So my interest in this for selfish reasons is primarily that this supports the hypothesis that perhaps there is a molecular signature of regeneration that occurs in patients that experience myocardial recovery with LVAD. Dr. Maryjane Farr: So Stavros, let's start with you. Give us the reason why to do this study. You mentioned some of the background. It'd be great to sort of talk for a moment about re-stage heart failure and then how it brought you to this study. Dr. Stavros Drakos: Thank you, Jane. So again, thank you for the opportunity to talk about the findings and the implications of this study. I like the way you are asking us to look a little bit at what led to this study and as you mentioned, the re-stage is a multi-center study that was performed in six US sites which showed in a reproducible fashion now given that we had single center studies from all over the world suggesting that, advanced heart failure is not an irreversible process that has to lead to end stage, an irreversible disease and what a re-stage demonstrated was that there is a subset of patients which if you select them based on clinical characteristics that we derived from other studies that were performed previously, you can achieve reverse remodeling, essentially a bad heart looking much better by every clinical, functional, structural characteristic in up to 50% of the selected patients. That's what re-stage showed. So having this finding now in a multicenter study, what made this study very timely was to be able to understand what drives this remarkable response. What are some of the mechanisms, as Hesham said, that we can if uncover take advantage of and expand this paradigm and enhance it and achieve reverse remodeling and recovery of even more patients and even go earlier in the disease process. So that's kind of how I would link the clinical findings that preceded this study with the motivation to perform the study and the implications of these findings for the ongoing translational and basic science research. Hesham Sadek: I'd like to ask a question here. So Stavros, do you think it's too early to sort of redefine the term reverse remodeling in this context to include perhaps some evidence of regeneration? Is there evidence of regeneration in this field or that's too premature to say? Dr. Stavros Drakos: I think the data are directing us towards the direction you just mentioned. I think that we can begin talking about it and planting the seed. We do have other evidence from work that you and others have performed indicating that this indeed is one of the mechanisms that drives this phenomenon and I think that the findings, especially in the cell cycle that we identified add to and contribute even more to that body of work that you and others have done. At this point, I will turn it to Sarah who can talk a little bit more about the findings related to the cell cycle that we identified in our study and I think that these may complete the answer to you, Hesham. Dr. Sarah Franklin: Yeah, I would love to comment. I think it's a really interesting phenomenon and really in these patient samples we were trying to understand molecularly what the difference is between individuals that respond positively to therapy and individuals that receive the same exact therapy and do not respond positively. So these are termed responders and non-responders and in our analysis we combined two platforms where we could molecularly interrogate what's different in these two tissues and try to see what is differentiating these populations. So what's consistent and reproducible different in responders and non-responders on a molecular level and in both the transcriptomic data and the phospho proteomic data, we saw clear patterns with cell cycle regulation and extracellular matrix or focal adhesion molecules and the interesting thing about cell cycle is cardiomyocytes have typically been thought to exit the cell cycle not long after birth and we see some interesting phenomenon either in humans or mice where we can have nuclei that have either multiple sets of chromosomes or multiple nuclei and there's some differences that have been observed in the nucleus with regards to disease, so hypertrophy, heart failure. So the molecules that we've identified, we saw a large difference in proteins involved in cell cycle regulation. Now the interesting thing is not all of those molecules are increasing or decreasing. We see a combination of molecules that are increasing or decreasing. But I think the other thing that's interesting is that these molecules, even though we are seeing changes in expression or changes in phosphorylation, exactly how that contributes to either cell cycle or cell cycle reentry or just nuclear function and transcription of proteins or genes or DNA regions is still what we need to continue to study. So exactly how these changes in proteins or transcripts related to the cell cycle, how they are exactly contributing to the physiological improvements that we're seeing is something that still needs to be investigated but is really important that that is a highlight of this study and as Stavros mentioned of previous work. Dr. Maryjane Farr: Stavros, tell us the design of the study. Dr. Stavros Drakos: Okay. So this study was performed in 93 patients that were prospectively enrolled in the Utah transplant affiliated hospitals here in Salt Lake City between the University of Utah, Intermountain Medical Center and the VA and these people came from all over the mountain west, the surrounding states of Utah and through our VA, through the state, from all over the west and south, from Alaska and Hawaii to Texas and we think it's a very representative population of our country's patient population and then we followed prospectively these people with serial echocardiograms so we can tell who will respond as Sarah said before, which essentially means which hearts are going to get better by echocardiographic criteria functionally and structurally, the dimensions of the heart shrinking and the ejection fraction improving to more than 40% and the dimension shrinking to normal range and then we compare these people, the subset of patients that have responded to the majority of patients actually that they have not responded. As we know these are advanced end stage patients and there is only a subset of those that they will favor respondents. As we said earlier, these subset can increase if you go selectively and pick these patients based on baseline characteristics. So then we analyze the tissue we got from these people when the LVAD went in, which is the core of the apex of the heart and compare that to the tissue we receive when the patients got transplanted and we got the whole heart. So in the meantime, as we just discussed, we phenotyped these people so we knew who were responders and non-responders and then we went back in the lab and tried to marry two basic processes, analyzing the transcriptome and the proteome and by doing that we were able to see some overlapping changes between the transcriptome and the proteome and we felt that by doing this overlapping analysis, we will increase the likelihood that what we are seeing, exponential mechanistic drivers will be the real mechanism and not just associations that you can frequently find when you do studies in humans and that's kind of a rough, brief summary of the design. Sarah, would you add something to that? Dr. Sarah Franklin: No, I think that's a great overview of it. I think what excites me about it is that this was first clinically observed that these patients were recovering and so I think the exciting part is the hypothesis was that there was some molecular underpinnings that could molecularly define these patients that were responding or not responding and so with that hypothesis we then carried out these analyses hoping that we would see a difference and we're very excited. It's very successful in that we found very clear, molecular differences that are reproducible between these patient populations. Dr. Maryjane Farr: So obviously there's lots of implications. Let me start with one very simple clinical one and that is, so based on some of the differences in the signatures and pathways that you saw for the next patient who needs LVAD therapy and you're trying to predict in some way whether they may be a responder or a non-responder, could you look at a biopsy sample and try to make some sort of prediction based on some of your findings so that they can choose a VAD over a transplant? That's a very clinical question and then I guess the second question is would it have to be a left ventricular myocardial sample? So are the differences? What do you think about that question? Or it's just too much too, far beyond? This is obviously a mechanistic study. But I'm just asking. Dr. Stavros Drakos: No, that's a great question and I'll start and Sarah can add later. So obviously it will be great if we can have a practical way to predict before the intervention who are the people that they will respond and that's one of the motivations for this study. It was not just to find the mechanism so we can make this phenomenon better and enhance it and find the mechanism, create new therapies. It was also the practical approach that you suggested, Jane, and I think that yes, this adds to the clinical predictors that we have already identified from other studies and yes, we could theoretically take the tissue and do this analysis. Is this the most practical thing we can say to the patient to biopsy the heart, right? It would've been better to be able to identify a biomarker in the plaque and we've done that. We started in other studies, identifying what's going on in the tissue and then going targeted in the blood and that's how we identified two cytokines and a two cytokines model, interferon gamma and TNF alpha being predictive as circulating biome. In this study we identify changes that can also inform future studies of biomarkers in the blood. But if we had a way to easily get the tissue and analyze the genes, yes, we could have done that as a predictor as well. The practical issue is that asking a patient for a biopsy just to predict the response to therapy may be something that most patients and most clinicians will consider way too advanced and complicated, right?that's why more work should and could be done to identify circulating biomarkers or other modalities that can help us interrogate what's going on in the heart related with these findings. But not that we cannot also do what you said. It's just more complicated. I don't know if Sarah would like to add to this. Dr. Sarah Franklin: I'd love to. I think that's a great overview. I think the only thing that I would add is that there are a number of conditions whether in the heart or otherwise in the body that you can use a single biomarker and it can be very predictive of conditions. Heart failure is so complex that often individual biomarkers are not sufficient enough to cover an entire population and all the nuances that can go into heart failure symptoms or syndromes and I think the exciting part about this study is it is one of the largest cohorts of patients that have been examined in this manner, which is exciting, but also that we have a multi-factor panel that is made up of multiple biomarkers that with the number of individuals that we examined is completely predictive of all of these patients. So these biomarkers are consistent and reproducible across all of these patients between responders and non-responders regardless of some of the nuances in the heart failure that they have and so it's very exciting because it's possible that a multifactorial panel could be much more applicable and last the test of time more so than an individual biomarker. I think the one other thing that is exciting like Stavros mentioned is that we did initially identify these in the left ventricle and it will be really exciting to see how far these biomarkers can be used if they can be used in potentially other aspects of the heart or blood, which obviously is less invasive and so that's not something that we've applied this panel to yet, but I think is a really wonderful extension of now saying, can we also identify some of these biomarkers in the blood which would be less invasive even if it's a fraction of them. That would still be wonderful. Dr. Maryjane Farr: I have so many clinical questions. But Hesham, what questions do you have? Hesham Sadek: Yeah, so the elephant in the room here obviously is that the variable is that these patients have an unloaded heart and there is evidence that unloading can reverse some of the changes that occur after birth with increasing ventricular load and initiate cascade of molecular events that may allow myocytes to proliferate. So this begs the question, is there a difference in how these ventricles of patients that recover versus those that do not recover see load? Are we able to measure load appropriately and is there a difference in load between these patients and if so, can this be improved or detection or measuring unloading or the degree of unloading clinically, can this be improved? Dr. Stavros Drakos: No, that's a great question and it provides the opportunity to talk about some of the things we can do on the clinical arena to further enhance this phenomenon. Yes, there are ways that we can use to tailor the mechanical unloading that we can provide in order to enhance this phenomenon. One way, and that's a study that we are proposing, is to use sensors, pressure sensors that can guide the way you function the machines, the devices, right? The way you remove part of the load and these sensors, some of them are clinically approved like cardioments and then without doing invasive procedures you can follow chronically how these patients are being unloaded and how the heart is responding to this unloading. We know that a lot of LVAD patients, despite doing clinically well, we know this from snapshot evaluations in right-heart cath studies, they are not optimally unloaded. They are feeling pressures left and right are not always optimized and so by doing this kind of prospective assessment of the mechanical unloading, you can tailor what you offer and the hypothesis generated is that by doing that you may be able to recover even more people. You can do this as we said, with approved sensors like cardioments or with other sensors that they are under investigation. You can also do more invasive stuff like PV loops. Of course these will require cathing these patients, which is a little bit more complicated. But it will provide more accurate assessment and it will also interrogate how the heart is improving and provide to you in-depth investigation and in-depth insights on also how the recovery process and the reverse remodeling process is being, I would say, digested by the heart and translated to functional response instead of just looking at it with an echocardiogram or the findings of a right-heart cath and these are studies that others have performed and have published and we know that they can give you a real good look into the systolic and diastolic function of the heart and how this is changing and improving down the road. So yes, that's the short answer. We can do that and we can tailor the unloading and potentially that's the hypothesis, maximize the effect that we saw here. Hesham Sadek: So this begs the question, maybe two questions here. One, is there evidence that patients who recover not from this study only but from other studies, is there evidence that patients who recover are more unloaded than patients that do not recover and the second question is: is it time to standardize assessment of mechanical load in patients with LVAD, especially those that will undergo or would be considered for recovery? Dr. Stavros Drakos: Yes. So that's a great opportunity to share with our audience what we know and what we don't know in this field in relation to your question about whether we know what is the optimum degree of unloading and the answer I think is that we need to know and understand more. What do I mean by that? There's this idea that the heart as every other organ after being unloaded and not working for some time may it lazy, may get atrophic and may need some rehab like the skeletal muscle when we put it in the cast and get atrophic and we need to rehab it when we remove the cast. So you can imagine that the LVAD and the unloading that provides, which in many cases may take over a significant part of the function of the heart may need gradual reloading as a second phase after the first phase of unloading and that's something that we've done. We have an ongoing study on this and also others have published that it may be beneficial. Of course, it needs to be validated and investigated further and to discuss about the degree of unloading in the first phase and what is the optimum degree of unloading, I would say even there, there is room for us to understand better what's going on and I think that we can investigate with ongoing studies right now whether full unloading versus partial unloading and measure the pressures using these sensors can translate to better changes functionally and structurally. I think that's something that is very doable and it would be very beneficial. What was the second part of your question, Hesham? Hesham Sadek: I was asking whether it's time to start standardizing some measure of unloading if these patients are planned for recovery? Dr. Stavros Drakos: Yes, and that's what we are doing. In all of these people, we report from the get-go what is their recovery score based on the intermixed ICARS derived score and when we have patients that they have high likelihood of recovery, we monitor them very closely and clinically what we do is just looking at the echo and whenever we do a right heart cath for clinical reasons. But in a prospective research study we could do more than just looking at the echo and occasional right heart cath and using the sensors we just discussed previously, you can tailor the unloading and begin prospectively unloading them in a more I would say well monitored wave. Yes. Hesham Sadek: So this is unloading or device specific parameters. Now are there patient specific parameters with regards to type of heart failure? So we talked initially about whether there's an element of regeneration specifically when it comes to cell cycle. But many patients with non-ischemic cardiomyopathy for example, don't have large scars and don't have lot of myocytes as the underlying cause of cardiomyopathy. Would you foresee that there is different mechanisms, for example, in these patients that don't have myocyte loss, that perhaps maybe it's not cardio myocyte proliferation and not regeneration? Dr. Stavros Drakos: Yes. So I think that the differential responses we get based on the heart failure theology warrant further investigation. Sarah and I have discussed that and actually we are following on our findings with larger number of patients so we can tease out these and I'll let Sarah talk a little bit more about it in a minute. But to answer the clinical part of this question, we don't know yet whether different parts of heart failure should be prescribed different modes of unloading. But the way you described it of course invites the hypothesis that of course different substrates, different injuries of the heart, as you said, it's a completely different failing heart if you have a big scar there versus a patient who has a mode of heart failure, another type of injury and would this be treated better and more effectively in terms of reverse remodeling by applying a different mode of unloading? That's things that we need to investigate further. But Sarah, would you like to comment on the potential on the effect of the different heart failure theologies on some of the findings we saw? Dr. Sarah Franklin: Yeah, definitely. So I think it's a really interesting question and in this analysis we included ischemic and non-ischemic samples in the patient populations and really we're just stratifying them based on responders and non-responders. When we start layering additional levels onto that, then we're effectively kind of reducing the potential numbers. So if we have 25 responders and we start breaking that down into ischemic and non-ischemic to see if there's another layer of biomarkers there, we actually did that we did not include it in this study. It's something that we're working on to add that. But we do reduce the number overall of patients in those two populations. So it would be fine to share that we were seeing stratification between ischemic and non-ischemic. But we did not feel like the numbers might be high enough within the responder and non-responder categories that warrant including that in this manuscript. So it's very intriguing that just responders and non-responders alone stratify as well as they do. They separate based on these biomarkers and it looks like it will also be possible in the future for us to even separate these samples further based on similar or additional biomarkers based on more specific factors in the etiology. So I think that will be another really exciting next step for future research. Hesham Sadek: My final question would be maybe a little bit broader than LVAD population, but definitely informed by this study. The term non-ischemic cardiomyopathy, do you think it's too broad and too vague for us to use in this setting because this encompasses many different types of cardiomyopathy that really are not nuanced enough by this definition. Dr. Stavros Drakos: Well, Jane was smiling while you were asking this question because we all as heart failure clinicians need to accept that it was not a good idea to name all of these different diseases non-ischemic cardiomyopathy when we did it or when this happened many moons ago. As you said, Hesham, and I couldn't agree more, these are completely different diseases. We need to understand them better and I think that the way we treat nowadays, chronic heart failure, many years down the road when people will look back, they will consider it a little bit, I would say, surprising that we were treating all of these the same way. We need more studies like the one we just did, that they will have enough numbers and that's when the issue becomes that you need enough numbers to be able to tell the differences between all of these non-ischemic cardiomyopathy types, theologies and if you go upstream, motivated and inspired by findings like this, we hope that we will be able to identify how to go and do a root cause analysis and treat these diseases, not down, down, downstream the same way, but going upstream, finding what really went wrong and treating them earlier in the molecular or other pathophysiological mechanism pathway that led to the heart failure and so yes, it was a bad idea to do that. But of course sometimes we do things because we don't understand it better, right? As one of our keynote speakers here in the recovery symposium said a few years ago, Jay Khan, the founder of Heart Failure Strata of America, some things look complicated until you understand them. Then when you understand them, they look simple. So here we don't really understand non-ischemic cardiomyopathy and how all these theologies lead there and I think studies like these can help us really inform the field better. But we will need, as Sarah said, more numbers. Dr. Maryjane Farr: So that was a great conversation. I wanted to just raise one last thing and that is what's so interesting about this cohort relative to re-stage heart failure is these were older patients and for re-stage heart failure, I think the average age was 35. So you would imagine there might have been one etiology for cardiomyopathy, uncontrolled hypertension or peripartum. But for cohorts in their fifties, there's probably an accumulation of different insults over many years time and so I thought that was particularly interesting from the point of view of that you were probably dealing with, again, a mixed bag of pressure overload, volume overload, maybe a genetic underpinning, whatever the life trajectory of some of these patients were and then lastly, the decision to try to go to recovery rather than to transplant, which would be the real world experience of why this wet pathway than the other. These are people truly in their fifties where they may have one or two surgeries in their lifetime left and so it's the relevant population that you're studying and so I'll leave it at that. That's a comment rather than a question, I think. But I think for heart failure clinicians, this is why the bench to bedside piece is so relevant to understanding this because it actually does change clinical practice, even if the mechanistic pathways may take still many more years to truly understand. It helps understand what's possible from an accrued clinical decision-making level. Dr. Sarah Franklin: Jane, if I might just comment on that, I actually think that's one of the most exciting parts about this dataset is that, as you mentioned, these patients have complex diseases. They are older. But yet we are still able to see consistent and reproducible differences between the patient populations that respond and don't respond and to me that suggests that at the end of the day there are consistent differences or reproducible or consistent molecular changes in cardiac tissue and in response to stress and I think that that gives us hope that we could potentially not only predict who would respond or not respond, but that as we get better at understanding the differences, that there could be potential therapeutic targets or therapies that would still be beneficial regardless of the complexity of the heart failure. Dr. Maryjane Farr: Okay. So Sarah, Stavros, thank you so much for spending time with Hesham and myself and look forward to EUCORS--I'm allowed to say that. Dr. Stavros Drakos: Of course. Dr. Maryjane Farr: Thanks so much. Bye. Dr. Greg Hundley: This program is copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
Please join author Subodh Verma and Guest Editor Christopher Granger as they discuss the article "Empagliflozin and Left Ventricular Remodeling in People Without Diabetes: Primary Results of the EMPA-HEART 2 CardioLink-7 Randomized Clinical Trial." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-host. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Peder Myhre: And I'm Dr. Peder Myhre, social media editor and doctor at Akershus University Hospital at University of Oslo in Norway. Dr. Carolyn Lam: Peder, I am so excited to be discussing this issue. So many great articles and a feature discussion coming up on the SGLT2 inhibitor, empagliflozin. And do you think it's got effects on left ventricular remodeling in people without diabetes? Very interesting question. Dr. Peder Myhre: That is so interesting, Carolyn. I can't wait to hear this discussion. Dr. Carolyn Lam: Yep, I agree, but we got to wait till we discuss the other papers in today's issue. I want to go first. So we know that non-vitamin K oral anticoagulants, or NOACs, they've become the standard therapy for preventing stroke and ischemic thromboembolism in most patients with atrial fibrillation. But, what is the effectiveness and safety of NOACs in patients on dialysis? That is hemodialysis. The AXADIA-AFNET 8 study sought to test the hypothesis that apixaban would be non-inferior to vitamin K antagonists in these very patients undergoing hemodialysis. Dr. Peder Myhre: Oh wow. This is really a gap of knowledge that we've been waiting to hear more about. NOACs in patients with hemodialysis. Tell us about this trial, Carolyn. Dr. Carolyn Lam: Sure. So this is from corresponding author, Dr. Reinecke, and colleagues, from University of Munster in Germany. And it's an investigator initiated prospective randomized open-blinded outcome assessment of 97 patients with atrial fibrillation on chronic hemodialysis randomized to either apixaban 2.5 mg BID, or a vitamin K antagonist, aiming for an INR between 2 and 3. Over a median follow-up time of 429 days for apixaban, and 506 days for the vitamin K antagonist, the composite primary safety outcome of first, major bleeding, clinically relevant, non-major bleeding, or all cause death, occurred in 46% of patients on apixaban, and 51% of patients on the vitamin K antagonist. That would be a hazard ratio of 0.91, with a p for non-inferiority being 0.157. How about the primary efficacy outcome? While this was a composite of ischemic stroke, all cause death, myocardial infarction, or deep vein thrombosis, and/or pulmonary embolism, and that occurred in 21% of patients on apixaban and 31% of patients on the vitamin K antagonists. Again, no difference when there was testing. So, in summary, Peder, there were no differences in the safety or efficacy observed between apixaban and vitamin K antagonists in patients with atrial fibrillation on chronic hemodialysis. Of note, however, even receiving oral anticoagulations, these patients remain at very high risk of cardiovascular events. So these data really support the consideration of apixaban for prevention of cardiovascular complications in patients with atrial fibrillation on chronic hemodialysis, but larger studies are definitely needed. Dr. Peder Myhre: Oh wow, Carolyn, that is so clinically relevant. And the next paper is also a clinically relevant paper. And it comes to us from the SPRINT authors. And to remind you, the SPRINT study was a study of intensive systolic blood pressure lowering compared to standard blood pressure lowering. And the results demonstrated that there was a robust reduction in both heart failure endpoints and all cause mortality. And in this sub-study that comes to us from corresponding author Jarett Berry from University of Texas Tyler School of Medicine, these authors look at the mechanisms through which intensive blood pressure lowering reduces the risk of these endpoints. And given the important role of cardiac injury and neurohormonal activation in the pathways leading from hypertension to heart failure, and strong association that has been observed between hypertension and levels of cardiac troponin and NT-proBNP, the authors hypothesized that intensive systolic blood pressure lowering would decrease levels of high sensitivity cardiac troponin T and NT-proBNP. Dr. Carolyn Lam: Cool. That's interesting. So how did they do this, and what did they find? Dr. Peder Myhre: So, as expected, Carolyn, the authors found that increases in troponin and NT-proBNP from baseline to 1 year were associated with a higher risk of heart failure and death. And there were really no significant interaction by treatment assignment. But let's look at the changes in troponin. And these results showed that randomization to intensive blood pressure lowering versus standard blood pressure lowering resulted in a significant 3% increase in cardiac troponin T level over 1 year follow up, and a higher proportion of participants with more than 50% increase, and that's with an odds ratio of 1.47. And Carolyn, in contrast, NT-proBNP decreased by 10% in intensive blood pressure arm. And these patients had substantially lower probability of increasing more than 50% in NT-proBNP, with an odds ratio of 0.57 compared to the standard arm. And now, to the most interesting part of this analysis, Carolyn, the association of randomized treatment assignment on changes in troponin was completely attenuated after accounting for changes in eGFR during the follow up, whereas the association of treatment with NT-proBNP changes were completely attenuated after adjusting for changes in systolic blood pressure. So Carolyn, the authors highlight in their discussion the importance of non-cardiac factors influencing variation in cardiac biomarkers, and raise questions about the potential role of cardiac troponin T as a surrogate marker for heart failure or death in blood pressure lowering studies. Dr. Carolyn Lam: Wow, very interesting. Thanks, Peder. Can I tell you now about a preclinical study? Very interesting, because it shows that cardiac inflammation and hypertrophy are regulated by a heart-brain interaction. Dr. Peder Myhre: Wow, Carolyn, a heart-brain interaction. I'm excited to hear more about this. Please explain. Dr. Carolyn Lam: I'd love to, but first some background. Interleukin-1 beta, now that is a pro-inflammatory cytokine that causes cardiac hypertrophy and heart failure. I need to familiarize you with this, the nucleotide-binding domain leucine-rich containing family, pyrin domain-containing-3, NLRP3 for short, which is an inflammasome, which is a cytosolic multiprotein complex that mediates active interleukin-1 beta production. Okay? So you know these terms, and now I want to tell you about the study. This is an elegant series of experiments performed by co-corresponding authors, Dr. Higashikuni, from University of Tokyo, and Dr. Sata, from Tokushima University Graduate School of Medicine, and their colleagues. They first showed that genetic disruption of the NLRP3 inflammasome resulted in significant loss of interleukin-1 beta production, cardiac hypertrophy, and contractile function during pressure overload. Next, a bone marrow transplantation experiment revealed an essential role of NLRP3 inflammasome in cardiac non-immune cells in myocardial interleukin-1 beta production and the cardiac phenotype. It was extracellular ATP released from sympathetic nerve terminals that induced the hypertrophic changes of cardiac cells in an NLRP3 and interleukin-1 beta dependent manner in vitro. And finally, depletion of ATP release from sympathetic efferent nerves, or ablation of cardiac afferent nerves, or a lipophilic beta-blocker, all reduced cardiac extracellular ATP, and inhibited the NLRP3 inflammasome activation, the interleukin-1 beta production, and the adaptive cardiac hypertrophy during pressure overload. So all of this suggests that controlling the neuronal brain signals might have therapeutic potential for the treatment of hypertensive heart disease. Neat, huh? Dr. Peder Myhre: Oh, that is so interesting. The heart and brain interaction. And, Carolyn, we're going to stay in the field of preclinical science. And now we're going to talk about another field that is really interesting, and that is regeneration of cardiomyocytes. Because, Carolyn, developmental cardiac tissue holds remarkable capacity to regenerate after injury, and consists of regenerative mononuclear and deployed cardiomyocytes. Whether reprogramming metabolism promotes persistence of these regenerative mononuclear and deployed cardiomyocytes that enhance cardiac function in repair after injury is unknown. Therefore, these researcher, led by corresponding author, Mohsin Khan, from Temple University School of Medicine, investigated whether the RNA binding protein, LIN28a, which is a master regulator of cellular metabolism, plays a role in cardiac repair following injury. Dr. Carolyn Lam: Wow. That is always, always interesting, regeneration and repair following injury. So what did the authors find? Dr. Peder Myhre: Well, Carolyn, through a number of elegant experiments, the authors made the following key findings. For the first time, they documented a role for RNA binding protein LIN28A in regulating cardiomyocyte turnover in the postnatal and adult heart. And LIN28a overexpression promotes cardiomyocyte cell cycle activity during postnatal development and extends cardiac regenerative ability of the mammalian heart to postnatal day 7. And in the adult heart, the authors could demonstrate that LIN28a drives new myocyte formation, augmenting cardiac structure and function after myocardial injury. And Carolyn, I'm sure you're going to ask the clinical implications of this study. Dr. Carolyn Lam: Indeed. Dr. Peder Myhre: And that is that these results may suggest a novel translational role for LIN28a based strategy to replenish cardiomyocytes in the adult heart after injury. Dr. Carolyn Lam: Very nice, Peder. Thank you. Also in the issue is a Research Letter by Dr. Bick on interleukin-6 receptor polymorphism attenuates clonal hematopoiesis mediated coronary artery disease risk among many individuals in the UK Biobank. There's also Cardiology News by Tracy Hampton, where she highlights few really interesting things, like aging cardiomyocytes accumulate new genetic mutations that was published in Nature Aging, cytokines promote tissue repair after a heart attack in mice, and that was published in Science, and scientists identifying molecular alterations in a failing heart at a single cell resolution, which was published in Nature. Dr. Peder Myhre: And there are a couple of other papers also in this issue, Carolyn. And there's first, an exchange of letters by Drs. Halushka, Lu, and Mayr, regarding the article "Circulating MicroRNA-122-5p is Associated with a Lack of Improvement in Left Ventricular Function after TAVR and Regulates Viability of Cardiomyocytes Through Extracellular Vesicles." And finally, we have an "On My Mind" piece by doctors Monda and Limongelli entitled "An Integrated Sudden Cardiac Risk Prediction Model for Patients with Hypertrophic Cardiomyopathy." Dr. Carolyn Lam: Oh, nice. Nice full issue. Thank you, Peder. Let's go to our feature discussion now. Shall we? Dr. Peder Myhre: Let's go. Dr. Greg Hundley: Welcome listeners to this feature discussion on January 24th. And we have with us Dr. Subodh Verma, from St. Michael's University in Toronto, Canada. And a guest editor, Dr. Christopher Granger, from Duke University in Durham, North Carolina. Welcome gentlemen. Well, Subodh, we will start with you. Can you describe for us some of the background information that went into the preparation of your study, and what was the hypothesis that you wanted to address? Dr. Subodh Verma: First, my great pleasure to be here, and thank you very much for the opportunity to discuss this paper with your viewers. As you know, SGLT2 inhibitors have been truly transformative therapies. From a heart failure perspective, we know that they prevent incident heart failure in people with diabetes who have vascular disease or risk factors. They also have been shown to treat prevalent heart failure in people with heart failure and either a reduced, mildly reduced, or preserved ejection fraction independent of glycemic status. And really, these have been the basis of very strong recommendations to use these agents in the prevention of heart failure in people with diabetes, and also in the treatment of prevalent heart failure in people with and without diabetes. Now, the fact that these drugs have such broad effects in people with heart failure has led to a theory that maybe these drugs could be introduced earlier on in the natural history of heart failure in people who neither have diabetes nor have significant heart failure, the so-called sort of stage A or stage B patient. But there really have been no clinical trials evaluating this question. There've been a lot of translational randomized trials that have provided some mechanistic insights about LV remodeling in people with diabetes or in people with prevalent heart failure. And we hypothesized that maybe the first step to evaluate whether SGLT2 inhibitors may have favorable effects on cardiac remodeling in people without diabetes or without heart failure would be to conduct a randomized double-blind control trial looking at indices of left ventricular remodeling in a population that I've just described. Dr. Greg Hundley: Very nice, Subodh. So you've started us into your study design. Maybe describe that a little more fully, and then who was included in your study population? Dr. Subodh Verma: So EMPA-HEART 2 CardioLink was a multi-center double-blind placebo control randomized trial in which we studied the effects of empagliflozin, an SGLT2 inhibitor, at a dose of 10 mg per day versus placebo in people who did not have type 2 diabetes or significant heart failure. We included people who were adults between the age of 40 and 80 who met 1 of 2 entry criteria. Either they had to have one major criteria, which was an increase in left ventricular mass index by specific echo criteria or MRI criteria, or they could have increased LVH as identified by ECG or by intraventricular septal or posterior wall thickness. They could also get in if they had resistant hypertension, hypertension despite being on 3 antihypertensive agents, or the second strata was entry through 2 minor criteria, which included a history of myocardial infarction, a GFR between 30 or 60, or evidence of overweight or obesity. Dr. Greg Hundley: And how many subjects did you randomize? Dr. Subodh Verma: So we randomized, of the 318 that we screened, 169 were randomized to receive empagliflozin 10 mg or a placebo. Patients had a baseline cardiac MRI done, and then the exposure was 6 months. They had a follow-up MRI at the end of 6 months. And the primary outcome measure was a 6-month change in left ventricular mass index from baseline to 6 months between the two groups. Dr. Greg Hundley: Very nice. And so , Subodh, can you describe for us now, what did you find? What were your study results? Dr. Subodh Verma: So, first and foremost, what we found in terms of baseline characteristics was that we enrolled a population of people with a mean age of around 60 with a BMI of around 30 kg/m2, predominantly men, about 80% or so were men. These were patients who did not have significant heart failure. The NT-proBNP at baseline was around 50 pg/mL. The eGFR was around 80 mL/minute, and the vast majority of these patients actually had a history of hypertension. Of course, none of them had diabetes by definition. The hemoglobin A1C was around 5.8%. Now what we found was, despite the fact that we went after patients who we thought would be enriched for a baseline increase in LV mass indices, the baseline LV mass index was mildly elevated, was around 63 g/m2. And over the course of 6 months, we did not find any significant difference in terms of LV mass regression between the placebo and empagliflozin groups. In fact, the adjusted treatment effect was minus 0.30 g/m2, which was not statistically significant. No other differences were found in terms of other indices of a remodeling, including left ventricular and diastolic or end systolic volume indices or in terms of left ventricular ejection fraction. There was a 2% increase in ejection fraction, and the p-value for that was 0.07, but really was not statistically significant. Dr. Greg Hundley: And very nice. And realizing that women may have smaller LV masses, any stratified analysis that evaluated effects on men versus women? And then what about, perhaps in the higher quartile versus lower quartile, of age? Dr. Subodh Verma: Right. So, Greg, we actually did look at various subgroups and covariates, including gender, including age. And age or gender did not really influence the overall result that we obtained. There was really a neutral result in empagliflozin, irrespective of these 2 covariates. We also looked at baseline blood pressure, baseline NT-proBNP, LV mass indices, the presence or absence of heart failure, chronic kidney disease. So for the covariates that we have evaluated over a short term of 6 months in this relatively low risk population, we did not find any heterogeneity the result, per se. Dr. Greg Hundley: Very good. Well, Subodh, thank you so much for that beautiful presentation. And listeners, now we're going to turn to our guest editor, Dr. Chris Granger. And Chris is an expert in the field of heart failure. Also, a lot of familiarity with HFpEF, which sounds a little bit, we're looking at precursors. We don't have HFpEF yet, but maybe trying to inhibit this from happening using empagliflozin. How do you put these results in the context with other studies that have emphasized utilizing SGLT2 inhibitors in patients with sort of a preserved ejection fraction and absence of diabetes? Dr. Christopher Granger: Yeah. Well thanks, Greg. And again, congratulations, Subodh, to your study. And I think you framed some of the context here as these drugs, the SGLT2 inhibitors, as being transformative, which I think is exactly right. And it's such a fascinating story. Right? These drugs, which we thought originally, with their cause of glucose spilling in the urine, and a modest decrease in blood glucose, might have a role for modestly improving glucose control in diabetes. And low and behold, they've turned out to be one of the great stories I think in recent, across all of medicine, in terms of their consistent and substantial improving clinical outcomes for patients with heart failure, with diabetes and cardiovascular disease, and now even kidney protection, and much broader implications. And their well tolerated, and they don't have dose titration. So there's some practical appeal to this class of drugs in terms of their benefits, in terms of clinical outcomes. But we're left with having this amazing evidence-based generated without really understanding why are these drugs so effective? And what are they doing? And you've provided, I think, an important piece to the puzzle. We did have the data from patients with diabetes and heart failure, with diabetes and left ventricular hypertrophy, that there is a modest reduce in LV mass with SGLT2 inhibitors. And what you've shown is that for patients that with mild LVH, with risk for LVH, that we simply don't see a substantial reduction in LV mass with the use of these drugs. So I think that provides this evidence that that's not a major cause of benefit, at least in this earlier phase of development of heart failure. And I think it really underscores the fact that there's a lot of work to do still to understand. We know that the renal effects are obvious place that these drugs have such an important benefit. And then the linkage of renal disease and cardiac performance is one of the areas, I think, that's a very exciting aspect of a probable contribution of the mechanism of these drugs. But I think in the end, we're left with still not really understanding why these drugs are so beneficial. But understanding that, I think, will be important, both for opening new avenues of targeting pathways, as well as being able to tell the clinical community, okay, you have these important benefits, but people do want to also know why are we seeing these benefits. Dr. Greg Hundley: Very nice. Well, listeners, we're going to turn back to Dr. Verma here. Subodh, what do you see is the next study to be performed in this sphere of research? Dr. Subodh Verma: Well, first, my thanks to Professor Granger, Chris, for handling this paper and for his very thoughtful comments. And he's absolutely right. We have such wonderful clinical data, and these results, of course, should not in any way take away from the importance of using empagliflozin or other SGLT2 inhibitors in the prevention of heart failure in people with diabetes, or in the treatment of HFpEF or HFrEF. But we're struggling with trying to understand what is the dominant mechanism of action here. And, in the previous precursor to EMPA-HEART 2, we did EMPA-HEART 1 in people with diabetes, and we saw a modest effect that was statistically significant of reduction in LV mass index. And we did not see this, of course, in a lower risk population without diabetes. And that tells me that remodeling may be occurring to a modest effect, it may require a longer time to actually show its benefits, but that this is unlikely a dominant sort of mechanism through which these drugs are working. And I do share Chris's thoughts that one of the key mechanisms of benefit that needs to be further explored is looking at the renal cardiac axes. We know that these drugs are profoundly renal protective, and that the benefits may actually be secondary to improvements in renal hemodynamics, improvements in renal function. And I think that is a population that needs to be, that's a mechanism that needs to be studied further. So I think the next generation of translational mechanistic studies need to really tease out the renal cardiac axes, maybe tease out populations that are at risk but have more significant left ventricular hypertrophy, maybe evaluate patients for a longer duration of treatment, or select people who truly have significant hypertension at baseline. I think those are groups and questions that need further exploration. And, of course, the translational science needs to be also studied in the context of larger completed clinical trials, where biomarkers are currently available and they can be linked, of course, to the outcomes in those trials. So those are some of my thoughts as to where the field could move towards. Dr. Greg Hundley: Very nice. And Chris, do you have anything to add? Dr. Christopher Granger: Subodh, I think that was a great summary. And I might just make a comment on the other end of the spectrum. That is, we have these drugs and the evidence of their benefit, and yet they're grossly underused in the populations that have proven to have benefit. Now it takes some time to educate, to get people familiar with, and get them to integrate these treatments into practice, but there's an enormous opportunity, and I think there is a linkage here. I think when people understand the mechanism, and when they're thoughtful about how these drugs may be working, that that really helps to make the case that the drug should be used, and that people are on board with using them. So I think there's this linkage here, there's the need to both better understand mechanism, and there's the need to have systems of care where these treatments are integrated to provide the benefit that's been so clearly shown in the randomized trials. Dr. Greg Hundley: Very nice. Well, listeners, we want to thank Dr. Subodh Verma, from St. Michael's University in Toronto, and our guest editor, Dr. Chris Granger, from Duke University in Durham, North Carolina, for bringing this paper highlighting that among people with neither diabetes nor significant heart failure but with risk factors for adverse cardiac remodeling, that SGLT2 inhibition with empagliflozin did not, did not, result in a meaningful reduction in LV mass index after 6 months. Well, on behalf of Carolyn, Peder, and myself, we want to wish you a great week, and we will catch you next week on the run. This program is copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Mads Liisberg and Guest Host Mercedes Carnethon as they discuss the article "Clinical Characteristics, Incidences, and Mortality Rates for Type A and B Aortic Dissections: A Nationwide Danish Population-Based Cohort Study from 1996 to 2016." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-host. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke, National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Poly Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, today's feature paper is about aortic dissections and it's the first nationwide population based study investigating the clinical characteristic, incidents, and mortality based on validated diagnosis of aortic dissection in a national patient registry. You want to hear more? Well, you have to just keep listening. Let's go on though first to discuss the other really important papers in today's issue, shall we? Dr. Greg Hundley: Absolutely. Dr. Carolyn Lam: You know what, Greg? I'm going to start while you grab a coffee. I want to talk about high sensitivity cardiac troponins and how they have allowed the use of strategies in the emergency department, for example, to rapidly rule out acute MI within one to three hours and potentially facilitate early discharge of low-risk patients. Now, the ability to rapidly rule out MI of course depends on the turnaround time of these high sensitivity cardiac troponin results from the central laboratory, which is often delayed due to specimen transport and handling and all these things. So, point-of-care assays can reduce this turnaround time by even 40 minutes, and early studies have actually used frozen plasma bio banks to assess these point-of-care assays... But no study has evaluated these point-of-care assays with fresh whole blood to safely rule out MI in the emergency department. That is until today's paper. So in today's study led by corresponding other Doctor Fred Apple from Hennepin Medical Center in Minneapolis, Minnesota and his team, they aimed to derive and validate an optimal high sensitivity cardiac troponin threshold concentration using whole blood point-of-care troponin eye assay on a single sample at presentation in the emergency department to identify patients at low risk of index MI for potential early discharge. Dr. Greg Hundley: Fascinating study Carolyn. So point-of-care testing, high sensitivity troponin from whole blood in the ED. So what did they find? Dr. Carolyn Lam: Among consecutive emergency department patients from two prospective observational studies with suspected acute coronary syndrome, a point-of-care, whole blood, high sensitivity cardiac troponin eye assay, the Atellica VTli provided a sensitivity of 98.9% and a negative predictive value of 99.5% for ruling out MI. A single measurement using a cutoff of less than four nanograms per liter for whole blood was successful in rapidly identifying patients at low risk of MI cardiac and all cause death and unplanned revascularization at 30 days. Dr. Greg Hundley: Very nice Carolyn, and could be quite practical. So Carolyn, my next paper comes to us from the world of preclinical science and it pertains to cardiac regeneration. So cardiac regeneration after injury is limited by the low proliferative capacity of adult mammalian cardiomyocytes. However, certain animals readily regenerate lost myocardium via process involving dedifferentiation, which unlocks their proliferative capacities. So inspired by this concept, these investigators led by Professor Patrick Hsieh from Academic Sinica, generated mice with inducible cardiomyocyte specific expression of the Yamanaka factors enabling adult cardiomyocyte reprogramming and dedifferentiation in vivo. Dr. Carolyn Lam: Wow. So what did they find, Greg? Dr. Greg Hundley: Right, Carolyn. So two days following induction, adult cardiomyocytes presented with a dedifferentiated phenotype, an increase proliferation in vivo. Microarray analysis revealed that the up-regulation of ketogenesis was central to this process. Now adenovirus driven HMGCS2 over-expression induced ketogenesis in adult cardiomyocytes and recapitulated cardiomyocyte dedifferentiation and proliferation observed during partial reprogramming. This same phenomenon was found to occur after myocardial infarction, specifically in the border zone tissue. And HMGCS2 knockout mice showed impaired cardiac function and response to injury, and so in summary, Carolyn, these data demonstrated the importance of HMGCS2 induced ketogenesis as a means to regulate metabolic response to cardiomyocyte injury, thus allowing cell dedifferentiation and proliferation as a regenerative response. Dr. Carolyn Lam: Wow, that's so cool. From cell regeneration to autoimmunity in this next paper. Now autoimmunity is increasingly recognized as a key contributing factor in heart muscle diseases. However, the functional features of cardiac autoimmunity in humans remain undefined due to the challenge of studying immune responses in situ. Now, these authors previously described a subset of c-Met expressing memory T lymphocytes, which preferentially migrate to cardiac tissue in mice and humans. In today's study, these authors led by co-corresponding authors, Dr. Federica Marielli-Berg and Saidi Mohidden from William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, and Queen Mary University of London, and their colleagues performed in-depth phenotyping of peripheral blood T cells in groups of patients with inflammatory and non-inflammatory cardiomyopathies, patients with non-cardiac autoimmunity and healthy controls... And they found that c-Met positive T cells were selectively increased in the circulation and in the myocardium of patients with inflammatory cardiomyopathies. The phenotype and function of c-Met positive T-cells were distinct from c-Met negative T cells, including preferential proliferation to cardiac myosin and co-production of multiple cytokines. Further, circulating c-Met positive T cell subpopulations in different heart muscle diseases identified distinct and overlapping mechanisms of heart inflammation. Furthermore, validation studies in experimental autoimmune myocarditis showed that elevations of auto-antigens specific c-Met positive T cells in peripheral blood, marked the loss of immune tolerance to the heart. Importantly, disease development could be halted by pharmacologic c-Met inhibition indicating a positive role for these c-Met positive T cells. Dr. Greg Hundley: All right, Carolyn, as you always ask me. So what's the take home message here? Dr. Carolyn Lam: This study demonstrates that the detection of circulating c-Met positive T cells may have utility in the diagnosis and monitoring of adaptive cardiac inflammation and additionally defined new targets for therapeutic intervention when cardiac autoimmunity causes or contributes to progressive cardiac injury... And this is discussed in an editorial by doctors at Abplanalp, Merten, and Dimmeler. Dr. Greg Hundley: Very nice, Carolyn. Wow. More fantastic preclinical science. Well, in the mail of the bag today, there is a Research Letter by Professor Burr entitled “Cannabis Inhalation Acutely Reduces Muscle Sympathetic Nerve Activity in Humans.” Dr. Carolyn Lam: There's an ECG Challenge by Dr. Reddy entitled “Shortness of Breath and Near Syncope During Exertion In a Child, When Patient Worry Syndrome.” There's also a Perspective by Dr. Weitz on what is the future of Factor 11 inhibitors. Dr. Greg Hundley: Well Carolyn, I'm looking forward to learning more about aortic dissections and that large Danish population-based study. Wow. Dr. Carolyn Lam: That's great. Let's go Greg. Dr. Mercedes Carnethon: Well, welcome to this episode of Circulation on the Run. My name is Mercedes Carnethon, an Associate Editor of Circulation, and Professor and Vice Chair of Preventive Medicine at Northwestern University. I'm really excited today to be here with the senior author of a really exciting paper that we're featuring on clinical characteristics, incidences and mortality rates for aortic dissections type A and B, a nationwide Danish population-based cohort study, and we have with us today Mads Liisberg. So welcome today. Dr. Mads Liisberg: Thank you. Dr. Mercedes Carnethon: So thank you so much for joining us and really thank you for sharing your important research with Circulation. This topic is so critically important, particularly given the high mortality rates associated with aortic dissections. Can you tell us a little bit about the work that you and your co-authors did in this important space? Dr. Mads Liisberg: Yes. Well actually the work originated when I started my PhD thesis and we got a registry data dump from the Danish medical registries and we found that almost none of our patients in the registry were registered with a specific aortic dissection code. So we did a validation study on the same time period from 1999 to 2006 where we went through all these medical records to ensure that we had the right aortic dissection TC 10 codes on population. Then we went a bit further and looked at the clinical characteristics of this patient, 'cause that's one of the really major things about Danish medical registries in our country, is that we have access to not only every patient's specific in hospital contacts, but also their medicine abuse, their drug use based on a TC code. So we can go really deep into each and everyone's drug history. When we did this study, we wanted to find out if the incidence rates during this timeframe had changed, which we find that it did, but also looking at mortality rates because, as you said, it's really high risk disease to be diagnosed with. So that's more the rationale for this study. Dr. Mercedes Carnethon: Thank you so much for sharing that. Certainly we know that the mortality rates from this are very high. I note that you report some changes over time between 1996 and 2016 in the incidents of these types of aortic dissections. So what did you find about the patterns of change in type A aortic dissections? Dr. Mads Liisberg: We found that it almost doubled from the beginning of our time period to the last, and the question is why is this? 'Cause that's one of the thing that the data doesn't reveal. We are only able to see that the incidence actually rises, but is it because that they are underdiagnosed in the beginning? Or is it because that we are better diagnosing in the end of the study that really are progressed? Dr. Mercedes Carnethon: That's a good question. I noted that when you studied the correlates of aortic dissection, you identified a number of characteristics and what stood out to me was the finding about the strong association of hypertension. I'm less aware of patterns of hypertension in the Danish population. Do you think that the changes in the prevalence of hypertension in the population contributed at all to these findings? Dr. Mads Liisberg: Well, most certainly, 'cause when you look at the prevalence of hypertension throughout any person's lifespan, the older they get the more likely they are to suffer from hypertension, and the Danish population has aged quite a lot in recent years. So I think that's one of the main reasons we find this, and also that most of our arctic dissection patients are actually quite old, which would correlate with hypertension as well. Dr. Mercedes Carnethon: One thing I really like, and you pointed this out, is really the richness of the data that you have in your health system, and I wonder, just going even a little deeper on the hypertension question, given that it is the most common medical diagnosis worldwide, were you able to study characteristics of hypertension that would be more strongly associated with aortic dissection? So for example, duration of hypertension, severity, prevalence of hypertension control? Dr. Mads Liisberg: That's actually a funny question 'cause the last study of my thesis, which hasn't been published yet or even submitted for that fact, examines the correlation between use and the risk of arctic dissection. On a very specific level, the way that hypertension is treated mostly in Denmark is with your general practitioner. So the way that we examine in studies like these, is that we look at prescription drug use. So if we find that an individual has a TC codes corresponding with anti-hypertensive drugs, then we are able to code them as hypertensive patients. Dr. Mercedes Carnethon: Okay, thank you for that. I always... I'm an epidemiologist myself, so I really love to see great population science studies and this registry is large, you have long-term follow up and you've got a great deal of data, but those people who feel as though it's obviously not appropriate to make causal conclusions around epidemiology and that perhaps epidemiologic findings shouldn't be driving clinical decision-making. In response to that, I think I would pose the question to you, which is how do you see clinicians and providers using this information from your observational study? Dr. Mads Liisberg: I think that's rather difficult. One of the findings that we present is to pose it over mortality for type B dissections when we exclude the 30-day mortality, but then we show that type A dissections have almost a corresponding mortality rate compared to a hypertensive cohort... And this finding is difficult to draw any clinical conclusions from, but there's actually a Danish randomized controlled trial just starting up in the next year. I think it's called the Sunday trial, where they will include all uncomplicated type B dissections and randomize them for treatment or no treatment, and the issue here is that you'll probably be over-treating some patients and under-treating others, but this discussion with the uncomplicated type B dissection has been ongoing for so many years. So it's difficult for me to just give one golden answer. Dr. Mercedes Carnethon: Certainly, and I appreciate the caution as we certainly don't want to overstep our findings. You did make a recommendation in the conclusion that it might be beneficial to treat type B aortic dissections more aggressively. Is this what you're alluding to, based on the other study that you're referencing? Dr. Mads Liisberg: Yes, yes, definitely. We see some clinicians being more cautious treating type B dissections with a TIVA or a surgery. So it's a difficult thing when they're uncomplicated, why treat them? But they can't be or become complicated quite easily and fast and then it's a difficult thing, because should you have treated them earlier? Or do you need to treat them now in their acute phase? Or wait for a chronic phase? It's a really good question. Dr. Mercedes Carnethon: No, I appreciate that and what I really love are the types of research studies that leave you with many more questions and next steps, and so I would like to really sort of bring us to a close with the big picture question, which is what do you see as the next steps in this line of research, given really what we all agree on is a very significant clinical problem. Dr. Mads Liisberg: We would really like to expand our database with even more clinical data as of now and include any image diagnostics for our cohort. So we're might be able to see any trends in our modulation before the dissection occurs. If any of our patients have any diagnostics done prior to being diagnosed. Dr. Mercedes Carnethon: I really want to thank you today for spending time talking with us. I know that our readers rarely have an opportunity to hear from everybody behind the scenes views on what the rationale was for carrying out a paper and really how the authors themselves hope that the paper will be used. So I really thank you for sharing that with us today, Matts, on behalf of your co-authors, this has been really a wonderful conversation, and thank you again for sharing your research with the journal, Circulation. Dr. Mads Liisberg: Oh, thank you for having me in for accepting our paper. Dr. Mercedes Carnethon: So thank you so much to our listeners for listening to us on this episode of Circulation on the Run. Please tune in next week as we will have more exciting insights. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Sean Pokorney and Associate Editor Shinya Goto as they discuss the article "Apixaban for Patients With Atrial Fibrillation on Hemodialysis: A Multicenter Randomized Controlled Trial." Dr Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and Backstage Pass of the journal and its editors. We're your cohost. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Carolyn, this week's feature, very interesting topic. In patients that have end stage renal disease that require dialysis, questions emerged should we anticoagulate them to prevent stroke, but of course, there's a risk of excess bleeding. Well, this feature discussion today is a study comparing apixaban and warfarin for anticoagulation in exactly this patient population. But before we get to those results, how about we grab a cup of coffee and go through some of the other articles in the issue? Would you like to go first? Dr Carolyn Lam: Absolutely, Greg. So my first paper is a pre-specified analysis of the Paradise MI trial and knowing you'll likely ask me what that was about, Greg, at least to summarize for everyone, the Paradise MI trial compared sacubitril/valsartan with ramipril and its effect on reducing heart failure events after an MI in more than 5,600 patients with an acute myocardial infarction complicated by LV systolic dysfunction, pulmonary congestion, or both. Now in today's paper, what Dr. Mehran and colleagues found was that among patients with a recent AMI and LV systolic dysfunction, heart failure are both, sacubitril/valsartan decreased the risk of coronary related events by 14% as compared with ramipril over a median follow-up of 22 months. The reduction in coronary events occurred with a favorable safety profile. Dr Greg Hundley: Wow, Carolyn, very interesting. Another indication perhaps for sacubitril/valsartan, especially relative to ACE inhibitors. So what does this mean for us clinically? Dr Carolyn Lam: Well, the results really cause us to consider if in addition to antiplatelets and lipid lowering therapies, sacubitril/valsartan may be explored as a potential agent to mitigate the residual risk in survivors of AMI. Of course, dedicated studies are necessary to confirm this finding and elucidate its mechanism. Dr Greg Hundley: Oh, very nice, Carolyn. Well, my first paper comes to us from the World of Preclinical Science and Carolyn, this study evaluated the scavenger receptors stabilin-1 and stabilin-2, proteins that are preferentially expressed by liver sinusoidal endothelial cells. Now, they mediate the clearance of circulating plasma molecules controlling distant organ homeostasis. And studies suggest that stabilin-1 and stabilin-2 may impact atherosclerosis. So in this study, the investigative team led by Professor Cyrill Géraud from the University Medical Center and Medical Faculty in Mannheim, Heidelberg comprehensively studied how targeting stabilin-1 and stabilin-2 affects atherosclerosis. Dr Carolyn Lam: Huh. All right, nicely explained. And so what did they find, Greg? Dr Greg Hundley: Right, Carolyn. So inhibition of evolutionary conserved class H scavenger receptors, stabilin-1 and stabilin-2, reduced aortic plaque burden in preclinical models and athero protection was mediated likely through down regulation on transcriptional factor ERG1 in monocytes by multifaceted plasma protein changes. And then finally, Carolyn transforming growth factor beta induced periostin, reelin, and they are novel ligands of stabilin-1 and stabilin-2 and are implicated in the development of atherosclerosis. Dr Carolyn Lam: Okay. Wow. Could you give us a take home message, please Greg? Dr Greg Hundley: Right. Carolyn, I knew you had asked me this. So here we go. Monoclonal, anti-stabilin-1 and anti-stabilin-2 antibodies provide a novel approach for the future treatment of atherosclerosis. And in the future, perhaps the plasma proteome composition may serve as a predictive factor, biomarker or surrogate parameter for cardiovascular disease in patients. Dr Carolyn Lam: Wow. Thanks Greg. My next paper is a true story of discovery. Now I could ask you what you know about the condition hypertension with brachydactyly type E... Greg, I love that expression. I wouldn't be able to answer that too. So let me tell you the story. So hypertension with brachydactyly type E is an autosomal dominant Mendelian disease resembling essential hypertension. Untreated patients die of stroke by the age of 50 years. Now, these authors had previously demonstrated a gain of function phosphodiesterase 3A gene mutations that caused the condition by increasing peripheral vascular resistance. They studied a large family with the condition earlier and were puzzled that cardiac hypertrophy and heart failure did not occur despite the decades of hypertension. And so they hypothesized that in the heart, this phosphodiesterase 3A or PDE3A mutations could be protective. Isn't that neat? And so corresponding authors, Doctors Bader, Klussmann, Bähring and Hübner, all from the Max Delbruck Center for Molecular Medicine in Berlin, Germany. So they studied new patients as well as CRISPR-Cas9 engineered rat models of this condition of hypertension with brachydactyly type E. And they comprehensively phenotyped all of them with the human induced pluripotent stem cells carrying these PDE3A mutations as well. So analyzing all of this from cells to new patients to CRISPR-Cas9 models. Dr Greg Hundley: Wow, Carolyn, what an interesting story. So what did they find? Dr Carolyn Lam: So while in vascular smooth muscle, the PDE3A mutations caused hypertension, in the hearts, they conferred protection against hypertension-induced cardiac damage, hypertrophy and heart failure. The mechanism involved long-term adaptations of mRNA and protein expression as well as calcium cycling. Non-selective PDE3A inhibition was a final short term option in heart failure treatment to increase cardiac cyclic AMP and improve contractility. So the data argued that mimicking the effect of PDE3A mutations in the heart rather than non-selective PDE3 inhibition was cardioprotective in the long term. And these findings could indeed facilitate the search for new treatments to prevent hypertension-induced cardiac damage. This is discussed in a really lovely editorial by Dr. Chiong, Houslay, and Lavandero. Dr Greg Hundley: Very nice, Carolyn. Wow. What another... we have such great articles from the World of Preclinical Science. Beautiful description as well. Well, we have some other articles in the issue, particularly from the Mailbag. And we have a Research Letter from Professor Thiagarajan entitled “Yield of Cardiac MRI in a pre-participation cohort of Young Asian males with T-Wave inversion.” Dr Carolyn Lam: Interesting. There's an exchange of letters between Dr. Xu and Huang regarding the article associations of dietary cholesterol, serum cholesterol and egg consumption with overall and cause-specific mortality with a systematic review and updated meta-analysis. There is a Perspective piece by Dr. Marcus on Smart watch detected atrial fibrillation, the value in positive predictive value. Isn't that interesting? And now onto that very, very important question of anticoagulation in patients with kidney disease. Can't wait. Let's go, shall we? Dr Greg Hundley: You bet. Carolyn. Welcome listeners to our December 6th feature discussion. And we have with us today Dr. Sean Pokorney from Duke University in Durham, North Carolina, and our associate editor, Dr. Shinya Goto from Tokai University in Isehara, Japan. Welcome gentlemen. Well, Sean, we're going to start with you. Can you describe for us some of the background information that went into the preparation of your study and what was the hypothesis that you wanted to address? Dr. Sean Pokorney: Yeah, absolutely. Thanks for having me to discuss the renal AF trial. And so I would say that the background information to the study was that we know that atrial fibrillation is an incredibly common condition in patients with chronic kidney disease. And the decision of anticoagulation in patients with end-stage kidney disease, on hemodialysis is really quite complex because these patients are at high risk for stroke and they're at high risk for bleeding. There are concerns with warfarin around calcific uremic arteriolopathy or calciphylaxis and there have been some data including from the original Aristotle trial that apixaban was even more favorable in terms of bleeding reduction relative to warfarin in patients with more advanced chronic kidney disease. Although patients with creatinine clearance less than 25 were excluded from Aristotle and really all patients with endstage kidney disease on hemodialysis have been excluded from all trials of atrial fibrillation in the past. And so we really wanted to evaluate the safety of apixaban versus warfarin in patients with end-stage kidney disease, on hemodialysis. And the hypothesis was that apixaban was going to be non-inferior to warfarin with respect to safety in terms of major or clinically relevant, non-major bleeding in these patients with atrial fibrillation and end stage kidney disease on hemodialysis. Dr Greg Hundley: Thanks so much, Sean. And you've mentioned the renal AF trial. So could you describe for us, for your, I guess, substudy, what was the study population? Who did you include and describe for us also your study design? Dr. Sean Pokorney: Yeah, absolutely. So the trial included patients who had end-stage kidney disease, and/or on hemodialysis, as well as having concomitant atrial fibrillation. And the patients had to have a CHA-VASc score greater than equal to two. All of the patients had to be on hemodialysis for at least three months. So these were chronic hemodialysis patients. And the study design was an open label randomized trial that was 1:1 randomization between apixaban and warfarin with blinded outcome evaluation. And again, the primary endpoint of the study was major or clinically relevant non-major bleeding based on ISTH definitions. And there were secondary endpoints looking at stroke, systemic embolism, death, medication adherence, and I think a really important sub-study looking at PK data. And the goal was to have 50 patients where we included PK data that was going to more represent what chronic apixaban dosing data would look like in these patients with end-stage kidney disease on hemodialysis. And originally the goal of the trial was to include over 700 patients. Originally we were trying to include 762 patients based on our initial power calculations to achieve true non-inferiority. Unfortunately, the trial enrollment was low and so the trial was ultimately stopped prematurely at 154 patients, although we were able to include the original targeted 50 patients in the PK substudy. The dosing that we used in the renal AF trial was 5 mg of apixaban twice daily unless patients had a second dose-reduction criteria in addition to chronic kidney disease. So the fact that they had end-stage kidney disease and were on hemodialysis counted as one dose reduction criteria and patients that were under 60 kilograms or less were 80 years of age or older, who had then a second dose-reduction criteria were treated with the 2.5 mg twice daily dosage. And this was important to note because this is different than the dosage that was used in the AXADIA-AFNET trial. Dr Greg Hundley: Very nice. And so Sean, what did you find? Dr. Sean Pokorney: Yeah. So again, a lot of this data is really exploratory because of the limited sample size, we weren't really able to definitively conclude anything about the major or clinically relevant non-major bleeding rates. I would say that some of the key findings that we saw was that there were high rates of major or clinically relevant non-major bleeding in both arms of the trial and one year bleeding event rates were 25% in the warfarin arm and 31% in the apixaban arm. And again, there was no statistically significant difference, although again, this is really exploratory. I would say that some of the other interesting findings that we saw was that there were very low rates of ischemic and hemorrhagic stroke in this patient population. Again, there were 82 patients randomized to apixaban, 72 patients randomized to warfarin. And there was a difference in the randomization because of the stratification by site that was performed with the randomization. And so within the 82 patients that were randomized to apixaban, the patients, there was one ischemic stroke and one hemorrhagic stroke. There were no hemorrhagic strokes in the warfarin population and two ischemic strokes. Another key finding was the high rates of mortality in this patient population. So 26% of the apixaban patients experienced a mortality event, 18% in the warfarin arm. So again, the mortality rates in these patient populations were extremely high. I would also emphasize some of the data from the PK analysis. So we looked at the PK analysis in two different ways. For the patients that were treated with the 5 mg dose of apixaban, the PK data showed that there was consistent overlap in the steady state concentration at one month compared to patients in the Aristotle trial that had really mild to moderate, moderate to severe and severe chronic kidney disease. And so there was a consistent overlap in those steady state concentrations between the end-stage kidney disease population on hemodialysis and the chronic kidney disease population who benefited from a apixaban in the Aristotle trial. Similarly, in the 2.5 mg apixaban dose, the patient who had a second dose reduction criteria in addition to chronic kidney disease, those patients had consistent steady state concentrations of apixaban relative to patients with mild to severe chronic kidney disease. Dr Greg Hundley: Very nice. Well thank you so much, Sean. And listeners, now we're going to turn to our associate editor, Dr. Shinya Goto. Shinya, can you, sort of, highlight for us some of the interesting findings that you see from these study results that Sean just presented? Dr. Shinya Goto: Thank you, Greg. Thank you, Sean for your wonderful summary of your study. We had a great discussion with an editor for this paper. As Sean pointed out, this is a kind of underpowered trial or just terminated early, hypothesis was not tested in the trial. But this population of patient clearly needs a real-world clinical trial, patient with atrial fibrillation, end-stage kidney disease, on hemodialysis; things a clinician could do. In some country, nephology society defined warfarin contraindicated in this population. As Sean pointed out, whether the development of this trial include this high-risk population patient. So we had a discussion whether the underpowered trial provided something or nothing may be better than something just provided here. Our consensus finally reached was, this limited trial still provide something like, you have to make a decision to use the anticoagulation. I mean, that the apixaban might be still used due to the PK data. That is the kind of interesting point of this trial. Dr Greg Hundley: Very nice Shinya. Well, Sean, turning back to you and Shinya with that nice lead in really, Sean, what do you think is the next study that needs to be performed in this sphere of research? Dr. Sean Pokorney: Yeah, absolutely. I think this is a challenging patient population to study. And again, our trial, the renal AF trial stopped early. Unfortunately, the AXADIA-AFNET 8 study also stopped early, which was also looking at apixaban versus warfarin outside the US and Europe. And so again, it is a challenging patient population to study. But again, I also think it's a really important population to study because one of the main unanswered questions in this population is whether or not they should receive anticoagulation. And so I think that ultimately more work and additional studies trying to determine whether or not these patients truly benefit from anticoagulation or stroke prevention, I think is really one of the critical directions that we need to take the field in. Dr Greg Hundley: And Shinya, do you have anything to add? Dr. Shinya Goto: Well, I fully agree with Sean. I mean, this is a very challenging area and still raising the question whether anticoagulation is necessary or not by your study. Maybe next generation oral anticoagulant such as Factor XI inhibitor that is more elevated to contact pathway may be beneficial. So we really need a good clinical study in this very important and known answered area. Dr Greg Hundley: Very nice. Well listeners, we want to thank Dr. Dr. Sean Pokorney from Duke University in Durham, North Carolina and our own associate editor, Dr. Shinya Goto from Tokai University in Japan for bringing us the results of this randomized open-label trial of apixaban versus warfarin in patients with chronic kidney disease on hemodialysis, revealing high rates of bleeding in both groups, but due to low enrollment, was unable to identify its non-inferiority endpoint. It's important to note, however, as both our author and editorialists have identified further research is really needed in this area to really examine the efficacy of anticoagulation for stroke prevention in this high-risk patient population. Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week On The Run. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
In this episode of the Heart podcast, Digital Media Editor, Dr James Rudd, is joined by Professor Carolyn Lam, a world expert in heart failure from the University of Singapore and the National Heart Centre, also in Singapore. They discuss updates in the diagnosis and management of heart failure, including wearables, biomarkers, the 4 pillars of therapy, and how and why there has historically been an under-representation of women in heart failure trials. This episode is sponsored by an educational grant from the Boehringer Ingelheim-Lilly Alliance. The sponsor has no influence over podcast content, the selection of speakers or any associated educational material. If you enjoy the show, please leave us a podcast review at https://itunes.apple.com/gb/podcast/heart-podcast/id445358212?mt=2 Circulation on the Run podcast - https://www.ahajournals.org/circ/podcasts
This week, please join authors Qiang Zhang and Matthew Burrage as well as Senior Associate Editor Victoria Delgado as they discuss the article "Artificial Intelligence for Contrast-free MRI: Scar Assessment in Myocardial Infarction Using Deep Learning-Based Virtual Native Enhancement." Dr. Carolyn Lam: Welcome to Circulation On the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your cohosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Peder Myhre: And I'm Dr. Peder Myhre from University of Akershus University Hospital in Norway. Dr. Carolyn Lam: Peder, today's feature discussion is on AI for contrast-free MRI. Isn't that so cool, using AI to perhaps understand what we could see only with contrast, but now in a contrast-free manner. Now I know that sound a bit confusing, but I hope very, very enticing, because everyone's going to have to wait for a little while before we get to that interesting feature discussion. And for now, let's talk about some of the papers we have in today's issue, shall we? Dr. Peder Myhre: Yes, Carolyn, I can't wait for the feature discussion, but we're going to start with some of the other papers in this week's issue, and we're going to start in the world of preclinical science with a paper looking at human cardiac reprogramming, because Carolyn, direct cardiac reprogramming of fibroblasts into cardiomyocytes has emerged as one of the promising strategies to remuscularize the injured myocardium. Yet it is still insufficient to generate functional induced cardiomyocytes from human fibroblasts using conventional reprogramming cocktails and underlying molecular mechanisms are not really well understood. Transcriptional factors often act in concert and form tightly controlled networks featuring with common targets among different transcriptional factors. Therefore, missing one component during heart development could lead to heart function defects and congenital heart disease. And in this study by corresponding author Yang Zhou from the University of Alabama at Birmingham, the authors perform transcriptomic comparison between human induced cardiomyocytes and functional cardiomyocytes to assess additional factors that govern transcriptional activation of gene programs associated with sarcomere contractility. Dr. Carolyn Lam: Wow. Really nicely explained. Thanks, Peder. So what did they find? Dr. Peder Myhre: So Carolyn, through these computational analysis of transcriptomic data, the authors identified TBX20 as the most under expressed transcription factor in human induced cardiomyocytes compared to endogenous cardiomyocytes. They also demonstrated that TBX20 enhances human cardiac reprogramming and improves contractility and mitochondrial function in the reprogrammed cardiomyocytes. Dr. Carolyn Lam: Nice. Could you summarize the clinical implications, please? Dr. Peder Myhre: Yes. So the clinical implications are that enhancing the efficiency and quality of direct cardiac reprogramming for human fibroblast is a critical step in the clinical translation of this technology, and better understanding of this synergistic regulation of key cardiac transcription factors during reprogramming will provide new insights into the genetic basis in normal and diseased hearts. Well, Carolyn, please tell me about your next paper. Dr. Carolyn Lam: Thanks, and we're moving now to kidney disease. Now end stage renal disease is associated with a high risk of cardiovascular events, but what about mild to moderate kidney dysfunction? Is it causally related to coronary heart disease and stroke? Well, today's authors give us a clue, and it's from corresponding author Dr. Di Angelantonio from University of Cambridge and colleagues who took a very unique combined approach to answer this question. They first conducted observational analyses using individual level data from four huge population based data sources, namely the emerging risk factors collaboration, Epic CVD, Jillion Veteran Program and UK Biobank. Can you imagine this comprised almost 650,000 participants with no history of cardiovascular disease or diabetes at baseline, yielding almost 43,000 and 15,700 incident coronary heart disease and stroke events respectively during a 6.8 million person years of follow up. So huge observational study, which they then followed with a Mendelian randomization analyses using a genetic risk score of 218 variants for GFR and involving participants in Epic CVD Million Veterans Program and the UK Biobank. Dr. Peder Myhre: Wow, Carolyn, this is a topic that I think many of us have really been wondering and thinking about. The mild to moderate kidney dysfunction, what does it really mean? And what a beautiful study to answer this. So what did they find? Dr. Carolyn Lam: First, there was a U-shaped association of creatinine-based GFR with coronary heart disease and stroke with higher risk in participants with GFR values below 60 or more than 105 mills per minute per 1.73 meters squared. Mendelian randomization analyses for coronary heart disease showed an association among participants with GFR below 60, but not for those with GFR above 105. Results were not materially different after adjustment for traditional cardiovascular risk factors and the Mendelian randomization results for stroke were nonsignificant but broadly similar to those for coronary heart disease. So in summary, in people without manifest cardiovascular disease or diabetes, mild to moderate kidney dysfunction is causally related to the risk of coronary heart disease, highlighting the potential value of preventive approaches that preserve and modulate kidney function. Dr. Peder Myhre: Thank you, Carolyn, for such a great summary and an important result from that study. I'm going to now take us back to the world of preclinical science and talk about diabetic cardiomyopathy and exercise. And we both know that patients with diabetes are vulnerable to development of myocardial dysfunction, and that exercise, our favorite thing, for maintaining cardiovascular health, especially in patients with diabetes. And despite a wealth of evidence supporting that cardiometabolic benefits of exercise, the precise exercise responsive signals that confer the beneficial effects of exercise in cardiomyocytes to remain poorly defined. And previous studies have identified fibroblast growth factor 21, FGF21, a peptide hormone with pleiotropic benefits on cardiometabolic hemostasis as an exercise responsive factor. And in this study from Aimin Xu from the University of Hong Kong, the authors investigated a six-week exercise intervention program in FGF21 knockout mice and wild-type litter mates that all had diabetic cardiomyopathy induced by high fat diet and injection of streptozotocin. Dr. Carolyn Lam: Nice. So what did they find? Dr. Peder Myhre: Yeah, the authors found that exercise lowers circulating FGF21 levels, therefore remodeling the heart as an FGF21 sensitive target organ. And the protective effects of exercise against diabetic cardiomyopathy are therefore compromised in mice with deficiency of FGF21. They also identified Sirtuin-3 as an obligor downstream effector on FGF21, preserving mitochondrial integrity and cardiac function. Finally, the authors demonstrated that FGF21 induces Sirtuin-3 expression through AMPK-FOXO3 signaling access. Dr. Carolyn Lam: So could you put that together for us better? So what are the clinical implications? Dr. Peder Myhre: So the clinical implications from this paper is that circulating FGF21 is a potential biomarker for assessment of exercise efficacy in improving cardiac functions. And exercise is a potent FGF21 sensitizer in cardiomyocyte and has the potential to enhance the therapeutic benefits of FGF21 analogs in diabetic cardiomyopathy, and selective activation of FGF21 signal in cardiomyocytes may serve as exercise mimetics and represent a promising targeted intervention for precise management of diabetic cardiomyopathy. Dr. Carolyn Lam: Oh my goodness. That is fascinating. Thank you, Peder. Well let's wrap up with what else there is in today's issue. There's an On My Mind paper by Dr. Weir entitled, “The Emperor's New Clothes: Aren't We Just Treating Grades of Heart Failure with Reduced Ejection Fraction.” Dr. Peder Myhre: And there is a Research Letter by Dr. James Martin from Baylor College of Medicine entitled “Gene Therapy Knockdown of Hippo Signaling Resolves Arrhythmic Events in Pigs after Myocardial Infarction.” Dr. Carolyn Lam: Very nice. Thanks, Peder. So wow, let's go onto a featured discussion on AI for contrast-free MRI and a virtual native enhancement here coming right up. Dr. Peder Myhre: Awesome. Dr. Carolyn Lam: Now we all know that myocardial scar is currently assessed non-invasively using cardiac MRI with late gadolinium enhancement as what we would call the imaging gold standard. Wouldn't it be amazing to have a contrast-free approach, which could provide the same information with many advantages such as a faster or cheaper scan, and without contrast associated problems? Well guess what? We're about to discuss that today in a feature publication in today's issue, and I am so pleased to have the co first authors with us today. They are Dr. Qiang Zhang and Dr. Matthew Burridge, both from University of Oxford, and to discuss it as well, our senior associate editor, Dr. Victoria Delgado from Barcelona. So welcome, everyone. Qiang Zhang, could I start with you and ask you, I understand you're a machine learning expert, which means you're probably smarter than all of us here. Could you maybe explain in simple terms what made you and Dr. Burridge do the study? Dr. Qiang Zhang: First? Thank you so much, Carolyn and Victoria, for the invitation. As you have mentioned, late gadolinium enhancement, or LGE, has been the imaging gold standard in clinical practice for myocardial catheterization including scar assessment for patients with myocardial infarction. However, LGE requires the injection for gadolinium contrast, and this is cautioned in some patient groups and increases the scan time and cost. On the other hand, pre-contrast CMR such as Sydney T1-T2 mapping, a gadolinium-free alternative for myocardial catheterization. But their clinical use has been hindered by confounding factors and a lack of clear interpretation. So with our cross deceptor team at Oxford, we developed an artificial intelligence, virtual native enhancement technique VNE. It can produce a sort of a virtual LGE image but without the need for gadolinium contrast. And we have previously tested it in patients with hypertrophic cardiomyopathy as published in this journal last year. And in this new study together with Matt here, we tested in patients with history of chronic or prior myocardial infarction. Dr. Carolyn Lam: Oh wow. Cool. So audience, you heard it. Instead of LGE, we now have VNE, virtual native enhancement. That's super cool. Thank you. Matt, could I bring you in here? So tell us a little bit more about the population you studied and what you both found. Dr. Matthew Burrage: Yeah, absolutely. And thank you so much for the invitation as well. So as Chang has said, this was a single sensor study that we performed at the University of Oxford and specifically targeting assessing myocardial scar in patients with a history of chronic or prior MI. So we had two sources for our population data. Well, first we used our real world clinical service data from our institution. So we screened 11 years worth of patient data for presence of MI. So patients were included. There was a evidence of a previous MI based on an ischemic pattern of LGE, but we specifically excluded patients who had an acute presentation, or if there were features of acute MI on the CMR scan such as presence of myocardial edema or microvascular obstruction. The reason for this is we wanted to keep this as a clean population to avoid the potential confounding effects of myocardial edema or MVO on native T1 values. And so we also excluded other myocardial pathologies such as underlying cardiomyopathies and infiltrative diseases. A second population dataset came from the OX Army study, which is a single center prospective study of patients presenting with acute MI. And for these patients we used their six month follow up scan to again avoid the confounding effects of edema and pathology. So overall we had a total of 912 patients who have contributed over 4,000 image data sets. The patient characteristics, 81% were male, they had a mean age of 64 years and there were cardiovascular risk factors such as diabetes melitis, hypertension, hypercholesterolemia in 20 to 40% of patients, while just over half had a history of previous revascularization. We also separately applied the VNE technology to a pig model of myocardial infarction, which was thanks to our collaborator, Rohan Domakuma in the US. And so those were scans performed eight to nine weeks after an induced MI in the LAD territory in a series of pigs. And so this gave us the ability to provide a direct comparison between LGE, VNE, and histopathology in this model. Dr. Carolyn Lam: Wow. And results? Dr. Matthew Burrage: So what we found and the key results were firstly that VNE provided significantly better image quality than LGE, and this was on blinded analysis by five independent operators from our test data sets. Secondly, the VNE correlated strongly with LGE in terms of quantifying infarct size and the degree of transmurality, so the extent of the MIs in our test data set. We had pretty good overall accuracy of 84% for VNE in detecting scar compared to LGE with no false positive VNE cases. And finally there was also excellent visuospatial agreement with the histopathology in the pig model of myocardial infarction. So really this, we think, is a technology that provides clinicians with images in a format that firstly they're familiar with, which looks like LGE, provides essentially the same information as LGE, but it can be achieved without the need for any gadolinium contrast agents and can be acquired in a fraction of the time. So it takes less than one second to generate the VNE image. So as we've said before, we feel there's a lot of potential here for this technology to potentially eliminate the need for gadolinium contrast in a significant proportion of CMR scans, reduced scan times and costs, increased clinical throughput and hopefully improve the accessibility of CMR for patients in the near future. Dr. Carolyn Lam: Oh wow. That is tremendous. So first of all, congratulations to both of you. Before I ask Victoria for some thoughts, could I also just check with Qiang Zhang, because all AI algorithms need to be externally validated or surely there's some catch to it, or so-called limitations, or something else you may study. Could you maybe round up by saying is there anything that clinicians should not be applying it to or be aware of some limitations or? Dr. Qiang Zhang: Thank you, Carolyn. So a limitation of this study is that the dataset that is used for developing the models, the majority of them are patients around six month after the acute infarction. So where the myocardial infarction is still evolving, which may include residual edema and microvascular obstruction, and that is difficult to assess using the current VNE model. And also we found it challenging to assess small sub endocardial infarction and actually to address those limitations, we are working on improving the VNE models, training it on even larger data sets and training it on LGE to detect small sub endocardial function. And we will further develop it to detect, for example, acute edema and a microvascular obstruction, and in the meantime develop quality control driven AI models to inform the clinical users of and unreliable results. Dr. Carolyn Lam: Wow, thank you. So Victoria, now I'm dying to hear your thoughts. How do you think this fits in the landscape of all AI imaging now? Dr. Victoria Delgado: I think that it's an excellent development and I congratulate the others for the article and the proof of concept that we can move away from the late enhancement and the use of gadolinium enhancement. I think that this is a major step forward because as Matt said, they are going to decrease very much the time of scanning and the post processing because is automatically done as far as I understand. So even if you can interpret yourself the amount of so-called virtual enhancement, the system gives you a value for that extension of the virtual in non-gadolinium enhancement. So that reduces very much the variability that can be in each observer if that is done automatically. But my question to them is also if that can be influenced by the type of scanner that you use, for example on echocardiography, that's much more my field of interest, it depends very much sometimes how the images are processed of which are the vendors that we have used to acquire the images. Is this a limitation for your software? Can you foresee there some variability or is completely independent? Dr. Qiang Zhang: Thank you, Victoria. So we are aware of actually the difference of the data produced by different scan of vendors and the advantage of AI-driven methods is that it is data driven. So we plan to incorporate dataset from other vendors so that the trend that VNE models can work with like multiple scanner vendors. This actually will be done alongside the ongoing standardization program of T1 mapping in our group, which is the underpinned technology for VNE. And this is led by Professor Stephan Pitchnik and Vanessa Farrera. And we actually hope the VNE technology as AI driven methods could contribute to a solution to the CMO standardization between the scanner vendor. Dr. Victoria Delgado: And another question, if I may follow in this CMR, it has been proposed as a very valuable imaging technique to assess infarct size and to see the efficacy of some therapies to reduce the myocardial infarction size. How do you think that this new methods will impact in future trials and the way we have been interpreting the previous trials, like for example, the one that you use for the validation? Dr. Matthew Burrage: Yeah, thanks Victoria. It's a really, really excellent question. I think there's a lot of potential for the new VNE technology to also become a clinical endpoint in some of these trials in terms of reduction in infarct size, because the information that we get is more or less the same as we get from the LGE. So there's lots of potential that we can, again, use this as a biomarker in trials for looking at reduction in infarct size and reperfusion therapies. But it has the benefit that it can be done quicker and without gadolinium contrast. Dr. Victoria Delgado: This is amazing guideline and really I would have a lot of questions for them as well. And knowing the literature, for example, in the Scenic center in Madrid that they have been scanning the evolution of myocardial infarction from 0.02 weeks to see how this would translate with your technique. That will be amazing to understand how this can be done. Dr. Carolyn Lam: Oh wow, there you go. New research idea right there. Well how about if we end with a very quick question for each of the first authors. So maybe Matt, you could start, I mean is this ready for primetime and clinical use? And if it's not, what needs to be done to get there? In other words, where are you headed as the next step? Dr. Matthew Burrage: So again, thank you, Carolyn, that's a really excellent question and I think the next step before this becomes ready for primetime clinical use is validating this technology really across the spectrum of other myocardial pathologies. So the next work that we are developing this on is in patients with acute myocardial infarction, and then extending this to sort of acute inflammatory conditions like myocarditis, other non-ischemic cardiomyopathies, things like amyloidosis as well. So this will be the next step into rollout and we are looking to track things like VNE burden and how that relates to clinical outcomes, similar to the previous LGE papers have done across different myocardial pathologies, but then ultimately aiming towards clinical rollout within the next few years. Dr. Qiang Zhang: Yeah, I think pretty much what Matt has said, we're going to develop the deep learning methods and test it further on pretty much the whole spectrum of commonly encountered diseases, and then more complex pathologies such as acute pathologies like edema, microvascular obstruction, and then we test on large population study like UK Biobank and other prospective clinical trials. And of course the most importantly is to roll out for real world clinical use. And as Matt said, we are aiming to do this within the next two to five years. Dr. Carolyn Lam: Wow, this is amazing. Both Victoria and I said thank you, congratulations on this landmark piece of work. Thank you for publishing it in circulation. Audience, thank you for joining us today from Greg, Peder, myself. You've been listening to Circulation on the Run, and don't forget to tune in again next week. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your cohosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center, and Duke National University of Singapore. And... Dr. Peder Myhre: I'm Dr. Peder Myhre from Akershus University Hospital, and University of Oslo in Norway. Dr. Carolyn Lam: Peder, I'm so excited about our future discussion. It's about a very important topic of detecting atrial fibrillation in the population using wearable devices. It talks about the Fitbit Heart Study. So exciting, but we're going to keep the audience waiting a bit, because we're going to talk about some other things in the issue. And I would love to start with this now. We know that fulminant myocarditis presentation is a rare and severe presentation of myocarditis. But, what is its natural history, and clinical features associated with poor outcomes? Peder, what do you think? Dr. Peder Myhre: Oh, that's a great question. We really don't know, because prior studies have been relatively small and selected. So Carolyn, let me know. Dr. Carolyn Lam: You're absolutely right. But today's paper from Professor Saito, from Nara Medical University in Japan and colleagues, is the largest nationwide cohort study of patients with histologically proven fulminant myocarditis presentation. They study 344 patients, hospitalized with histologically proven myocarditis, who underwent catecholamine and/or mechanical support from 235 cardiovascular training hospitals across Japan, between 2012 and 2017, and here's what they found. Over a median follow up of 600 days, the accumulative risk of death or heart transplantation at 90 days was 29%. So, really high. These were the risk factors associated with a higher risk of death or heart transplantation, and they were non-sinus rhythm, older age, ventricular tachyarrhythmia, lower left ventricular ejection fraction. Severe histological damage was also associated with a worse 90 day outcome in lymphocytic myocarditis. Cool, huh? Dr. Peder Myhre: Oh wow. That was some really solid data. And now Carolyn, I'm going to take us over to the world of preclinical science. And the next paper entitled at “APIC Associated De Novo Purine Synthesis is Critically Involved in Proliferative Arterial Disease” by Yuqing Huo from Augusta University in Georgia. Dr. Carolyn Lam: Cool. Dr. Peder Myhre: And as you know, Carolyn, vascular smooth muscle cells are extremely important in vascular health. They're located in the medial layers of arteries, and normally exhibit a contractile phenotype that contributes to the regulation of blood vessel tone, blood flow distribution, and blood pressure in normal mature blood vessels. And in response to disease processes, the vascular smooth muscle cells are switched to an activated synthetic and proliferative phenotype, that contribute to the development of a variety of arterial diseases, including atherosclerosis, in-stent restenosis, and bypass graft occlusion. And nucleotides that we are familiar with, such as ATP and GTP, are essential for a large number of biological processes in cells, including proliferation. And Carolyn, the previous studies have demonstrated that de novo synthesis of purine is a critical pathway for nucleotide synthesis. And in this study, the authors assessed the role of de novo synthesis of purine in vascular smooth muscle cells by using knockout mice. Dr. Carolyn Lam: Oh, that was beautifully explained. Thanks, Peder. So what did they find? Dr. Peder Myhre: So the authors found that the de novo purine synthesis was increased in proliferative vascular smooth muscle cells. Moreover, they identified an important enzyme in the process called A-P-I-C, APIC. Which was observed in the neointima of the injured vessels, and atherosclerotic lesions in both mice and humans. Finally, they showed that in a mouse model with knocked out APIC, the atherosclerosis and arterial restenosis was attenuated. Dr. Carolyn Lam: Cool. So tell us what the clinical implications are. Dr. Peder Myhre: So these findings provide novel insights into the reprogramming of purine metabolism underlying vascular smooth muscle cells proliferation in the development of arterial disease. And that targeting APIC may be a promising therapeutic approach to combat arterial diseases. So Carolyn, please tell me about your next paper. Dr. Carolyn Lam: Ah, thanks, Peder. Well, back to the clinical world, this time, talking about arrhythmogenic right ventricular cardiomyopathy. We know that is characterized by progressive cardiomyocyte loss and fibro fatty replacement. And we know that patients with this a ARVC are at risk for life-threatening ventricular arrhythmias and sudden cardiac death. The placement of an ICD is a crucial component of ARVC management. But arrhythmic risk stratification and the selection of the optimal candidates for ICD, especially for primary prevention of sudden cardiac death, has, of course, been challenging. As background, a ventricular arrhythmia risk calculator, in patients without previous sustained ventricular arrhythmias, has been proposed, and includes seven clinical variables derived from non-invasive tests that are routinely performed in these patients. However, the possibility of integrating additional parameters, such as ventricular tachycardia inducibility on programmed ventricular stimulation, with this risk calculator, has been suggested, but not conclusively investigated in a large cohort. And so, here comes corresponding author, Dr. Cadrin-Tourigny, from Montreal Heart Institute and colleagues, who studied 288 patients with a definite ARVC diagnosis, no history of ventricular arrhythmias at diagnosis, and programmed ventricular stimulation performed at baseline. And these patients were identified from six international ARVC registries. Dr. Peder Myhre: Oh wow. So we're talking risk stratification for patients with ARVC. Such an interesting topic, Carolyn. So please tell me, what did they find? Dr. Carolyn Lam: So, programmed ventricular stimulation significantly improved risk stratification, above and beyond the calculator predicted risk of ventricular arrhythmias, in a primary prevention cohort of patients with ARVC. And this was mainly for patients considered to be at low and intermediate risk by the clinical risk calculator. If negative, its high negative predictive value of 93% in low and intermediate risk patients, may support the decision to forego ICD use in some patients. So, programmed ventricular stimulation results may be applied to the non-invasive ARVC risk calculator, in a two step approach to facilitate personalized decision making for ICD in such patients. Dr. Peder Myhre: Thank you, Carolyn. That was a great summary and a great paper. So we're going to move in to see what else is in the mail bag, Carolyn. Dr. Carolyn Lam: You bet. There's a letter by Dr. Agirbasli regarding the article, “Coronary Artery and Cardiac Disease in Patients with Type Two Myocardial Infarction, A Prospective Cohort Study,” and this, followed by a response by Dr. Chapman. There's an ECG Challenge by Dr. [Jingnan] Han, entitled, “Tachycardia Associated with Pacing.” From our own Molly Robbins, we have highlights from the Circulation Family of Journals. And she covers the experience with stereotactic radio ablation and electrical storm, reported in Circulation: Arrhythmia and Electrophysiology. The impact of accessibility to primary care on hypertension awareness and control is reported in Circulation: CV Quality and Outcomes. There's an analysis of lifestyle factors and their impact on the risk of heart failure by background genetic risk, and that's in Circulation: Heart Failure. There's a deep learning model of PET scans and coronary flow reserve reported in Circulation: CV Imaging. And finally, OCT based measurement of stent expansion and associations with outcomes are presented in Circulation: CV Interventions. A lot. Dr. Peder Myhre: Yeah, and there's more, Carolyn. In this issue, there is an extensive Frontiers review by the AF-SCREEN International Collaboration, entitled, “Consumer LED Screening for Atrial Fibrillation.” There is also a Research Letter by corresponding author Qi Fu, from University of Texas Southwestern Medical Center entitled, “Neuro Cardiovascular Dysregulation During Orthostasis in Women with Posttraumatic Stress Disorder.” And finally, a Research Letter by Pankaj Arora from University of Alabama entitled, “Mechanical Circulatory Support Devices Among Patients with Familial Dilated Cardiomyopathy, Insights from the INTERMACS.” Dr. Carolyn Lam: That's awesome, Peder. Thank you. Now let's go onto our feature discussion on atrial fibrillation detection and the Fitbit Heart Study, shall we? Today's feature discussion is about the Fitbit Heart Study, and none other than the first and corresponding author Dr. Steven Lubitz, from Massachusetts General Hospital in Boston to join us today. Steve, welcome. Congratulations. Am I right to say, this is the largest study of its kind to look at the detection of atrial fibrillation using wearable devices? Dr. Steven Lubitz: Thanks for having me, Carolyn. And that's right, this is. Dr. Carolyn Lam: Oh my gosh. Okay. Tell us all about it, what you did, what you found. Dr. Steven Lubitz: Well, thanks, Carolyn. So as we know, undiagnosed atrial fibrillation is a potential hazard that can cause strokes. And if we can identify people who have undiagnosed atrial fibrillation early, we may be able to prevent strokes. In addition, undiagnosed atrial fibrillation may be associated with additional morbidity, which can be addressed through a number of different ways, if we can detect atrial fibrillation. Obviously, the challenge is to detect atrial fibrillation. We also know that people are increasingly wearing devices that have sensors on them, specifically using photoplethysmography technology, which can detect the pulse rate. Software algorithms can now be developed, that can assess that pulse rate for regularity or irregularity. But they really need to be assessed and validated, to minimize the potential for false positives, which can have obviously, downstream adverse consequences of their own, if atrial fibrillation is incorrectly identified or diagnosed as a result. As I was mentioning, we developed this novel software algorithm with frequent overlapping photoplethysmography, post tachogram sampling, which is unique. And then we tested the algorithm's positive predictive value for undiagnosed AFib in a large scale remote clinical trial, using a range of Fitbit wearable fitness trackers and smart watches. It was a remote trial, so participants were invited. These were people who already had a Fitbit account, they were invited to participate. And in span of just a few months, in the middle of the pandemic, over 455,000 people signed up to participate in the study. And so, big thank you to all of the participants in the study. Dr. Carolyn Lam: Wow, that is big. And what did you find? Dr. Steven Lubitz: So of the 455, over 455,000 participants that enrolled, over 4,000, had an irregular heart rhythm detection and received a notification. And after inviting those participants to attend a telehealth visit, and at that telehealth visit, the telehealth provider confirmed eligibility criteria, confirmed that they didn't have preexisting atrial fibrillation, for example, and a variety of other inclusion/exclusion criteria. They were mailed a one week ECG patch, that they applied themselves, and then returned that ECG patch. So in the end, after those exclusions, in participants that returned analyzable patches, 1057 participants were included in this ECG monitoring analytic cohort, of whom, 340 had atrial fibrillation during that ECG patch monitoring period. The primary endpoint of the study was the positive predictive value of irregular heart rhythm detection that occurred during the ECG patch monitoring period. So a participant had to have an irregular heart rhythm detection to get notified that they were eligible to meet with a telehealth provider and receive an ECG patch monitor. And then, they had to have another irregular heart rhythm detection during ECG patch monitor wear. So the primary outcome was the positive predictive value of the first irregular heart rhythm detection for concurrent atrial fibrillation that occurred during ECG patch monitoring. Dr. Carolyn Lam: Okay. Cool. So many questions here, but maybe you should tell us the results first. Dr. Steven Lubitz: Sure. So the primary endpoint, the positive predictive value of the IHRD during ECG patch monitoring was 98.2% in the overall cohort. And it was similar between men and women, and those aged 65 or older, or those aged less than 65. And I should mention that, in this study, about 13% of participants enrolled in this study overall, were above the age of 65. Dr. Carolyn Lam: And you included more women than in prior similar studies. Right, Steve? Dr. Steven Lubitz: Yeah. Dr. Carolyn Lam: I was going to congratulate you for that. Dr. Steven Lubitz: Yeah, that's right. That's right. We're very excited to see that. Dr. Carolyn Lam: Okay, so that's cool. Wow. A positive predictive value of 92%. So couple of things here with- Dr. Steven Lubitz: 98. Dr. Carolyn Lam: Sorry, 98%. That's right. Wow. Okay. Now with this AFib detection, it's always about duration. Right? And what do you call a positive alert? Could you maybe elaborate a bit about that here? Dr. Steven Lubitz: Sure. So I think this is an important point. A few points. One, the algorithm is designed. This particular algorithm requires at least 30 minutes of an irregular pulse to be detected, in order for a detection to occur. Which means that, this is unlikely to be detecting trivial amounts of atrial fibrillation. And indeed, that's what we observed. We observed that the median burden of atrial fibrillation was 7% among those who had AFib on the ECG patch monitor. We observed that the median longest episode of atrial fibrillation was seven hours. And just by way of comparison, in other studies in which ECG patch monitors have been distributed to people without this irregular pulse pre-screening, the burden is usually on the order of only a couple of percent, tops. So this, by nature, these types of algorithms, and this algorithm specifically, probably enriches for individuals who have a higher burden of atrial fibrillation. Meaning that, if these detections occur, then it's probably not detecting trivial amounts of atrial fibrillation. Dr. Carolyn Lam: Right. And a lot of it seems to send a very clear message that this study, and perhaps even the algorithm, is designed to be specific. Right? So that duration, as well as what you used as the outcome. How much price do you pay in terms of sensitivity? Do you know what I mean? Since we optimized for specificity, am I right to say that? Dr. Steven Lubitz: Sure, that's a great point. The algorithm is really optimized for specificity, as you mentioned. And although we didn't specifically calculate the sensitivity of the algorithm, in a secondary analysis, we examined the sensitivity of an IHRD during that ECG patch monitoring period, to detect any AFib that was documented on the ECG patch monitor, and it was about 67%. So we know that we probably don't detect some atrial fibrillation. Largely, that's a function of this technology at the moment. It's very difficult to assess the pulse rate during periods of activity in motion. So a lot of these algorithms, and this algorithm in particular, doesn't operate during periods of motion. The accelerometers and the devices can tell the algorithm that motion is occurring, and then the algorithm won't operate on that information at that time. So a lot of this has to do with limitations of the technology at the moment. Dr. Carolyn Lam: Ah. So the detection probably occurs best at rest or at night. Dr. Steven Lubitz: That's exactly right. And we encourage participants to wear their devices at nighttime during the study. Dr. Carolyn Lam: Oh, cool. And then of course, I suppose a question you'd anticipate, I mean, we know about the Apple Heart Study, we know about the watch study, and how does this compare? How is this technology different, and the results? Dr. Steven Lubitz: Essentially, one of the most remarkable things about these studies is that, it appears that this pulse rhythm pre-screening really enriches substantially for people who have atrial fibrillation. So for example, in the Fitbit Heart Study, we observed that about 32% of people who had an irregular heart rhythm detection and then returned an ECG patch monitor, had AFib on it. And by comparison, in the Apple Heart Study, that number was about exactly the same, just over 30% or so. So when we further compare this pre-screening type approach to confirming atrial fibrillation, using an ECG patch monitor, with other approaches in which say, elderly individuals were mailed ECG patch monitors to screen for atrial fibrillation, we usually only see detection in the order of four to 5% of people. So this irregular pulse based pre-screening markedly enriches for atrial fibrillation. And we also know, this is only a one week ECG patch monitor, and if we monitor people longer than one week, we're likely to detect more atrial fibrillation, since this is often paroxysmal atrial fibrillation that we're detecting. So there are a lot of similarities, and I think the point is that, these types of consumer electronic devices are going to be great tools for identifying undiagnosed atrial fibrillation in the community. I think we have a lot of challenges ahead of us, in terms of figuring out how to integrate that information into our routine healthcare workflow, and counseling consumers and users of these types of technology on exactly what they should be doing when they do get an alert. And then also, counseling providers on how to act on these findings, what they mean and how accurate the technology is. Dr. Carolyn Lam: Yeah. And I appreciated a sentence in your manuscript that talks of, what are our society guidelines going to say? If you could look into a crystal ball now, Steve, based on what you found, what would you advise both patients and clinicians, if you don't mind? Dr. Steven Lubitz: Well, I think that, in short, if a clinician is alerted by a patient, that they received in a regular heart rhythm detection on their device, in short, I would say, don't blow it off. Take it seriously. Because the odds are, that it does represent an abnormality, and the odds are that that abnormality is atrial fibrillation. And given the potential adverse consequences of undiagnosed atrial fibrillation, there's a real opportunity to intervene, and prevent morbidity in the patient. And then, if you're a consumer who happens to have one of these devices, and you've turned on this feature, and hopefully you have, if you do have an alert, don't blow it off. Contact a provider. Because it may very well mean that you have an irregular heart rhythm that merits attention, and could be addressed to prevent downstream consequences and morbidity for you. Dr. Carolyn Lam: Nice. And keep your Fitbit on at night. Dr. Steven Lubitz: Yes. And if you do want to maximize the utility of these algorithms that use photoplethysmography, probably wearing them at nighttime will maximize the sensitivity, or utility of the devices and algorithms. Dr. Carolyn Lam: Aw, that's just great. What nice take home messages. Thank you so much, Steve, for publishing this really unique and important study in Circulation. So audience, you heard it right here on Circulation on the Run. From me, Greg, and Peder, please do tune in again next week. Speaker 4: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors, or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join authors Kevin Roedl and Sebastian Wolfrum, as well as Associate Editor Mark Link as they discuss the article "Temperature Control After In-Hospital Cardiac Arrest: A Randomized Clinical Trial." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary, and backstage pass to the Journal and its editors. We are your cohosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center, and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor and Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature, very interesting, a randomized clinical trial of temperature control after in-hospital cardiac arrest. But before we get to that exciting study, let's grab a cup of coffee, and jump in and discuss some of the other articles in the issue. Carolyn, would you like to go first? Dr. Carolyn Lam: Yes. Starting with a great quiz. So Greg, which is better? How about this? It's multiple choice. Is it A; transradial, or B; transfemoral access, in terms of post-procedural mortality? Dr. Greg Hundley: I'm going to go with transradial. It has been, hopefully, I'm okay on this. It just seems so many fewer complications. Dr. Carolyn Lam: But that's exactly that we need to meta-analyze the studies that have been done. Exactly what this paper did, led by Professor Valgimigli, from USI in Lugano, Switzerland. So what they did is, they performed an individual patient data meta-analysis of 21,600 patients, enrolled in seven multi-center randomized control trials, comparing the transradial with transfemoral access, among patients undergoing coronary angiography with or without PCI. And they found that transradial access was associated with a lower incidence of the primary outcome of all-cause mortality, and the co-primary outcome of major bleeding at 30 days, compared to transfemoral access. There was also evidence for reductions in major adverse cardiac and cerebral vascular events, net adverse clinical events, vascular complications, excess site bleeding, and blood transfusion. MI, stroke, and stent thrombosis, did not differ. And crossover was higher in the transradial access group. At predefined subgroup analysis, the authors confirmed that the benefit observed the transradial group was generally consistent across the majority of pre-specified subgroups, except for those with significant baseline anemia. Patients with baseline anemia appear to derive a substantial mortality benefit with transradial access rather than transoral access, compared to those with mild or no anemia. So, the authors concluded, that the meta-analysis provides evidence that transradial access should be considered the preferable access site for PCI, in patients with acute coronary syndrome, supporting most recent recommendations on the preferential use of this radial approach. So you were right, Greg. Dr. Greg Hundley: Very nice, Carolyn. A really important piece of science to disclose to our listeners, in that hurried state, and moving quickly door to balloon times, et cetera. And here we find another positive outcome in study result for transradial approaches. Well Carolyn, as we know, my next paper, it's really going to come to us from the world of preclinical science. And it pertains to hypertension, which is a common cardiovascular disease, and is related to both genetic and environmental factors. But the mechanisms linking the interplay between the domains of genetics and the environment have not been well studied. Now, DNA methylation, a classical epigenetic modification, not only regulates gene expression, but is also quite susceptible to environmental factors. Thereby, linking environmental factors to genetic modifications. So therefore, Carolyn, these authors, including Professor Jingzhou Chen, from Fuwai Hospital, National Center for Cardiovascular Diseases, and the Chinese Academy of Medical Sciences, and the Peking Union Medical College, and their colleagues, felt that screening differential genomic DNA methylation, in subjects with hypertension, would be important for investigating this genetic environment interplay in hypertension. So this study, Carolyn, like many from the world of preclinical science and circulation, incorporated both human and animal model subjects. Methodologically differential genomic DNA methylation in hypertensive, pre-hypertensive, and healthy control individuals, was screened using the Illumina 450K BeadChip, and then verified by pyrosequencing. Plasma oviduct glycoprotein 1, or OVGP1 levels, were determined using an enzyme-linked immunosorbent assay. And OVGP1 transgenic and knockout mice were generated to analyze the function of OVGP1. Dr. Carolyn Lam: Wow. Nice approach, Greg. And what did the authors find? Dr. Greg Hundley: Right, Carolyn. These authors found a hypomethylated site at cg20823859 in the promoter region of OVGP1, and the plasma OVGP1 levels were significantly increased in hypertensive patients. This finding indicates that OVGP1 is associated with hypertension. Now Carolyn, in OVGP1 transgenic mice, OVGP1 over expression caused an increase in blood pressure. Also, dysfunctional vasoconstriction, and vasodilation, remodeling of the arterial walls, and increased vascular superoxide stress and inflammation. And these phenomenon were exacerbated by angiotensin II infusion. In contrast, OVGP1 deficiency, attenuated angiotensin II induced vascular oxidase, stress, inflammation, and collagen deposition. Now pull down, and co-immunoprecipitation assays showed that myosin heavy chain 2A, or MYH9, interacted with OVGP1. Whereas, inhibition of MYH9 attenuated OVGP1 induced hypertension and vascular remodeling. Dr. Carolyn Lam: So Greg, let me try to summarize, is that okay? So hypomethylation, at that specific site in the promoter region of the OVGP1 gene, is associated with hypertension, and induces its upregulation. The interaction of this OVGP1 with myosin heavy chain 2A contributes to vascular remodeling and dysfunction. And so, OVGP1 is a pro hypertensive factor, that promotes vascular remodeling by binding to this myosin heavy chain. So, really cool stuff. Thanks for teaching us. Dr. Greg Hundley: Very good. Dr. Carolyn Lam: Well thanks so much, Greg. And we go back to the clinical world now, and ask the question, what is the efficacy and safety of prophylactic full dose anticoagulation and antiplatelet therapy, in critically ill COVID-19 patients? So I'm going to tell you the results of the COVID-PACT trial. And this was a multi-center, two-by-two factorial, open label, randomized controlled trial, with blinded endpoint adjudication in 390 ICU level patients. So, severely ill patients with COVID-19, from 34 US centers. Patients were randomized to a strategy of full dose anticoagulation, or standard dose prophylactic anticoagulation. And in the absence of an indication for antiplatelet therapy, patients were additionally randomized to either clopidogrel or no antiplatelet therapy. Dr. Greg Hundley: Ah, Carolyn. So what did they find? Dr. Carolyn Lam: Full dose anticoagulation substantially reduced the proportion of patients experiencing a venous or arterial thrombotic event, and there was no benefit from treatment with clopidogrel. Severe bleeding events were rare, but numerically increased in patients on full dose versus standard dose prophylactic anticoagulation, without any fatal bleeding events, GUSTO moderate or severe bleeding was so significantly increased with full dose anticoagulation, but with no difference in all-cause mortality. So in summary, in a population of critically ill patients with COVID-19, a strategy of prophylaxis with full dose, versus standard dose prophylactic anticoagulation, but not the addition of clopidogrel, reduced thrombotic complications, with an increased risk of bleeding, driven primarily by transfusions in hemodynamically stable patients, with no apparent excess in mortality. Dr. Greg Hundley: Very nice, Carolyn. What a important piece of information, as many of us around the world are taking care of critically ill patients with COVID-19. Well, how about we see what is in the mail bag this week? So first, Carolyn, there's a Frontiers piece by Dr. Packer, entitled, “Critical Reanalysis of the Mechanisms Underlying the Cardiorenal Benefits of SGLT2 inhibitors, and Reaffirmation of the Nutrient Deprivation Signaling Autophagy Hypothesis.” Next, there's a Research Letter, from Professor Airaksinen entitled, “Novel Troponin Fragmentation Assay to Discriminate Between Troponin Elevations in Acute Myocardial Infarction and End-stage Renal Disease.” Carolyn, there's another Research Letter, from Professor Solomon, entitled, “Aptamer Proteomics for Biomarker Discovery in Heart Failure with Reduced Ejection Fraction.” Also, Carolyn, [a] wonderful Cardiovascular News summary from Tracy Hampton, reviewing three articles. First, “Mechanisms Behind Cannabis Effects on Heart Health.” The second, “Exercise Inducible Metabolite Suppresses Hunger.” And then lastly, “Piezo1 Initiates the Cardiomyocyte Hypertrophic Response to Pressure Overload.” Dr. Carolyn Lam: Cool. There's also an exchange of letters between Doctors Jha and Borlaug on latent pulmonary vascular disease in therapeutic atrial shunt. And finally, an On My Mind, by Dr. David Kass entitled, “What's EF Got To Do, Got To Do With It.” I love it. You must read it. It's so, so cool. All right. But now, let's go on to our feature discussion, shall we? Dr. Greg Hundley: You bet, Carolyn. Welcome listeners, to our feature discussion today, and really delving into the world of in-hospital cardiac arrest, and how we manage those patients. And we have with us today, Dr. Kevin Roedl from Hamburg, Germany, Dr. Sebastian Wolfrum from Lubeck, Germany, and our own associate editor, Dr. Mark Link from University of Texas Southwestern in Dallas, Texas. Welcome gentlemen. Kevin, we're going to start with you. Can you describe for us, some of the background information that went into the construct of your study, and what was the hypothesis that you wanted to address? Dr. Kevin Roedl: Thank you, Greg. We thank you for the kind invitation to this podcast. We're very likened to do this podcast with you. And so, talking about the background of hypothermia in-hospital cardiac arrest, we have to go back like two decades almost, because there were two studies in New England Journal of Medicine published 2002, who introduced mild therapeutic hyperthermia to the treatment in post cardiac arrest. Primary, these two studies show the benefit of the therapy in this kind of patients. And then, 2003, it was introduced in also the international guidelines. However, these studies only addressed out-of-hospital cardiac arrest patients, and also, only shockable rhythms. And so, the question arised over the years, what about other patients like non shockable rhythms, or also in-hospital cardiac arrest? And so, that's basically was the primary aim of our study to address this special population. Because when you see the states, the numbers, there are 290,000 in-hospital cardiac arrests a year. So it's actually, a very large population. And there's no randomized control trial to show any benefit, or maybe harm, in this group. There were some observational studies, 2016 in China published. From China, in this group, they looked at the Get With The Guidelines registry, and actually, they saw that there was probably a negative influence of hypothermia in the study. However, it was only observational. So actually, there were no randomized control trials. And that primary hypothesis was, that we wanted to know actually, does thus mild therapeutic hyperthermia work in this group of patients in the in-hospital cardiac arrest setting? And what is the outcome? Is it like in the out-of-hospital cardiac arrest setting, or not? Dr. Greg Hundley: Wonderful, Kevin. And so, can you describe for us then, your study population and your study design? Dr. Kevin Roedl: Yes, of course. We did a randomized control trial. There were over 1000 people screened, and overall, we included 242. So you see how hard it is to get people in there. And actually, in terms of hypothermic temperature control, we are 120 about, and long term at 118, and the final others of the endpoints. And when we look at the baseline characters of these patients, they were well balanced actually, about 72 years. When we look at the initial cardiac arrest rhythm, that's interesting because about 70% non-shockable rhythms, and 25% shockable rhythms. And probably also interesting, the location of the cardiac arrest. Medical boards about 50%, and ICU or ED was 22%. So that's probably summed up the baseline characteristics of our study. Dr. Greg Hundley: Perfect. And so Kevin, can you describe for us what was the hypothermic target for the group that was going to have their temperature recused? Dr. Kevin Roedl: Yes, hypodermic target was 32 degrees to 44. And so two degrees Celsius, basically the same target like in earlier trials. Dr. Greg Hundley: Very nice. Well listeners, now we're going to turn to our second co-author, Dr. Sebastian Wolfrum. And Sebastian, can you share with us the study results? Dr. Sebastian Wolfrum: Yes, Greg. Thank you very much for the opportunity to participate in this podcast. Only wanted to include unconscious patients, and therefore, we took a time and took 45 minutes after their cardiac arrest, to let the patients get away if they did so. We also excluded patients that had severe functional deficit before the cardiac arrest; since we could not really define the neurological outcome if we would've included those. And we didn't see any differences. Neither in mortality, not in the functional outcome, either when they're treated with 33 degrees Celsius, or whether normothermia was used. The death rate after six month was in a range which is comparable to other in-hospital cardiac arrest studies, and higher than those performed in the out-of-hospital cardiac arrest studies. It was about slightly over 70% in both groups. And the number of patients with the good functional recovery after six months was 23% of the patients in the hypothermia group, and 24% of the patients in the normothermia group. And if we look at only the survivors, we see that the ones which are worse functional outcome, were most of them dead after six months. We then also focused on the temperature curves in our patients, and to see whether we have achieved our goal. And we saw that we have reached the target temperature within four and a half hours after cardiac arrest in our hypothermia group. Which is not as fast that we had expected, but still in the range, which is comparable to other studies on this field. And we also saw that our control group was about 37 degrees, within the first 12 and 48 hours. So we truly avoided fever, which has not been done in every previous study on cardiac arrests. Dr. Greg Hundley: Very nice. And any differences between the hypothermia and normothermia groups, related to the age of the patient? Or, whether or not they had a shockable rhythm at the time of presentation? Dr. Sebastian Wolfrum: We saw as a result of our study, that age is a predictive factor for mortality. But age did not differ between our treatment groups, and therefore, did not interfere with our results. And we didn't see differences in the shockable or non-shockable rate in our patients in the different treatment groups. Dr. Greg Hundley: Thank you. Well listeners, now we're going to turn to our associate editor, Dr. Mark Link, one of our expert electrophysiologists at Circulation. And Mark, you have many papers come across your desk, and what attracted you to this particular paper? Dr. Mark Link: There were a number of things. One, it's hard to do RCTs in resuscitation, and I thought they did a very nice job with this RCT. Two, the subject of hypothermia, or therapeutic temperature management, is a very hot one in resuscitation. It's one of the few treatments in the past that have been shown to make a difference in outcome. And so, all of those trials were done in out-of-hospital arrest. So to have a trial done in in-hospital arrest was very intriguing also. And I think we're all disappointed that it wasn't a positive trial, but we have to take the negative trials also. And I think, part of the reason it may have been a negative trial is because the normal thermic group avoided hyperthermia. And I think that's something that's coming out of a lot of these trials is avoid fever. It may not be so important to get hypothermic targets, actually, looks like it's probably not, but it looks like it's very important to avoid fever. Dr. Greg Hundley: Very nice. Well listeners, we're going to turn back to our expert panel here really, and start with you Kevin. Kevin, what do you think is the next study that needs to be performed in this sphere of research? Dr. Kevin Roedl: Thank you for this interesting question. Yeah, a bunch of studies could be performed, especially maybe in the out-of-hospital cardiac arrest study, because we don't know. This fever harmful, we have to find certain subgroups in which this treatment works. So maybe in this subgroups there is data on this and it could be a benefit. So these are, I think, the two main topics that should be done in the future. Dr. Greg Hundley: Thank you. Sebastian, what are your thoughts? Dr. Sebastian Wolfrum: As Mark said, the hypothermic treatment was, for decades, maybe the only treatment which we could give to cardiac arrest patients, which has been proven to reduce mortality. And all other studies following didn't see any be benefit of hypothermia, not even in a subgroup. Also, the TTM trials did not. So I'm questioning myself, where is the original HACA study group that benefits? Where did this hide in the other studies? So I would think, to do another study in out-of-hospital cardiac arrest patients, whether in ventricular fibrillation that had shown in the HACA trial to reduce mortality. This should be done in a similar way to the original study, to see whether there is this subgroup. People who support the idea of hypothermia also focus very much on the fast onset of their hypothermic treatment. And they say we saw a difference in mortality in the HACA trial, and we could very fast. And I think the other studies have to show that they cool as fast as the HACA study. So the main focus should be on the time calls of hypothermia after cardiac arrest, cooling very fast to a target temperature of 33 degrees, maybe holding on for 24, maybe 48 hours. Dr. Greg Hundley: Very nice, Sebastian. So focusing on the speed and the timing of that cooling. And Mark, anything to add? Dr. Mark Link: Yeah, so if I sit here with my writing group hat on for the HA and say, "What are we going to do for the resuscitation guidelines in 2025?" I think you look at the totality of the data for targeted temperature management. And I think, the main thing you say, walking away from this, is avoid fever. Don't let your patients get hot. I'm not sure you can say much more than that right now, until we get more data. Dr. Greg Hundley: Very nice. Well listeners, a really interesting provocative discussion today. And we want to thank Dr. Kevin Roedl from Hamburg, Germany, Dr. Sebastian Wolfrum from Lubeck, Germany, and our own associate editor, Dr. Mark Link from Dallas, Texas, bringing us the results of this study highlighting that hypothermic temperature control is compared with normothermia did not improve survival, nor functional outcome, at 180 days in patients presenting with coma after in-hospital cardiac arrest. Well, on behalf of Carolyn and myself, we want to wish you a great week, and we will catch you next week On The Run. This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors, or of the American Heart Association. For more, please visit ahajournals.org.
ESC TV Today brings you concise analysis from the world's leading experts, so you can stay on top of what's happening in your field quickly. This episode tackles: Cardiology this Week Factor XIa Inhibitors: A Breakthrough in Anticoagulation? Heart Failure Treatment: New Concepts for 2023 and Beyond Snapshots Host: Susanna Price Guests: Carlos Aguiar, Robert Storey, Carolyn Lam and Stephan Achenbach Want to watch that episode? Go to: https://esc365.escardio.org/event/602 Disclaimer: This programme is intended for health care professionals only and is to be used for educational purposes. The European Society of Cardiology (ESC) does not aim to promote medicinal products nor devices. Any views or opinions expressed are the presenters' own and do not reflect the views of the ESC. Declarations of interests Stephan Achenbach, Nicolle Kraenkel, Susanna Price and Robert Storey declared to have no potential conflict of interest to report. Carlos Aguiar declared to have potential conflict of interest to report: personal fees for consultancy and/or speaker fees from Abbott, Alnylam, Amgen, AstraZeneca, Bayer, Boehringer-Ingelheim, Daiichi-Sankyo, Ferrer, Gilead, Lilly, Novartis, Pfizer, Sanofi, Servier, Tecnimede. Davide Capodanno declared to have potential conflict of interest to report: Sanofi, Daiichi Sankyo, Terumo, Medtronic, Chiesi. Carolyn Lam declared to have potential conflict of interest to report: Carolyn S.P. Lam is supported by a Clinician Scientist Award from the National Medical Research Council of Singapore; has received research support from Bayer and Roche Diagnostics; has served as consultant or on the Advisory Board/ Steering Committee/ Executive Committee for Actelion, Alleviant Medical, Allysta Pharma, Amgen, AnaCardio AB, Applied Therapeutics, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Cytokinetics, Darma Inc., EchoNous Inc, Eli Lilly, Impulse Dynamics, Intellia Therapeutics, Ionis Pharmaceutical, Janssen Research & Development LLC, Medscape/WebMD Global LLC, Merck, Novartis, Novo Nordisk, Prosciento Inc, Radcliffe Group Ltd., ReCor Medical, Roche Diagnostics, Sanofi, Siemens Healthcare Diagnostics and Us2.ai; and serves as co-founder & non-executive director of Us2.ai. Emma Svennberg declared to have potential conflict of interest to report: Institutional research grants from Bayer, Bristol-Myers, Squibb-Pfizer, Boehringer- Ingelheim, Johnson & Johnson, Merck Sharp & Dohme
This week, please join author Sunil Rao and Guest Editor and Editorialist Gregory Lip as they discuss the article "A Multicenter, Phase 2, Randomized, Placebo-Controlled, Double-Blind, Parallel-Group, Dose-Finding Trial of the Oral Factor XIa Inhibitor Asundexian to Prevent Adverse Cardiovascular Outcomes After Acute Myocardial Infarction" and the editorial "Factor XIa Inhibition: Is It a Novel Alternative Antithrombotic Strategy for High-Risk ACS Patients?" Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, today's feature paper is about the factor XI inhibitor asundexian. It's the trial that we've been waiting for the PACIFIC-AMI trial. You really have to listen to it because these factor XI inhibitors are super interesting. What? We're going to tell you about the other papers in today's issue first. Aren't we, Greg? Do you want to go first? Dr. Greg Hundley: You bet, Carolyn. Thank you so much. Carolyn, did you ever consider the genetic underpinnings of venous thromboembolism? Well, as you know, venous thromboembolism is a complex disease with environmental and genetic determinants. And in this study, this large investigative team represented by Dr. Nicholas Smith from the University of Washington in Seattle, and their colleagues present new cross-ancestry meta-analyzed genome-wide association study results from 30 studies with replication of novel loci and their characterization through in silicone genomic interrogations. Dr. Carolyn Lam: Wow. Sounds like a really large effort, Greg. What did they find? Dr. Greg Hundley: Right, Carolyn. In the author's initial genetic discovery effort that included 55,330 participants with venous thromboembolism: 47,000 were European, 6,000 African, and a little over 1000 Hispanic ancestry. They identified 48 novel associations of which 34 are replicated after correction for multiple testing. In their combined discovery replication analysis, so that's 81,669 venous thromboembolism participants and ancestry stratified meta-analyses from the European, African and Hispanic ethnic groups. They identified another 44 novel associations, which are new candidate venous thromboembolism associated loci requiring replication. And many of the replicated loci were outside of known or currently hypothesized pathways to thrombosis. Carolyn, in summary, these findings from this very large GWAS analysis highlight new pathways to thrombosis and provide novel molecules that may be useful in the development of anti-thrombosis treatments with reducing the risk of bleed. Dr. Carolyn Lam: Wow. Super interesting and very related to that feature paper that we just discuss. But nonetheless, this next paper I love as well, if I may say so myself. It deals with frailty and as we know, frailty is increasing in prevalence. And because frail patients are often perceived to have a less favorable benefit risk profile, they may be less likely to receive new pharmacological treatments. And so, we and led by Professor John McMurray from the University of Glasgow, decided to investigate the efficacy and tolerability of dapagliflozin according to frailty status in the DELIVER trial. Dr. Greg Hundley: The DELIVER trial. Carolyn, tell us about the DELIVER trial? Dr. Carolyn Lam: Sure. In deliver dapagliflozin compared to placebo, reduced the risk of worsening heart failure events or cardiovascular death and improved symptoms in more than 6,000 patients with heart failure and mildly reduced and preserved ejection fraction, so ejection fraction above 40%. Now in this pre-specified analysis, we examine the efficacy and safety of dapagliflozin according to frailty status. That was determined using the Rockwood cumulative deficit approach. And so, what we found was that greater frailty was associated with more impairment of health status and worse clinical outcomes in patients with heart failure and ejection fraction of 40%. The beneficial effects of dapagliflozin compared to placebo on clinical outcomes were consistent regardless of frailty class. But interestingly, the improvement in symptoms, physical function and quality of life were larger in the frailest patients. Adverse events were not more common in individuals randomized to receive dapagliflozin compared to placebo irrespective of frailty class. And so, the take home message is the benefit risk balance related to frailty in patients with heart failure with mildly reduced and preserved ejection fraction is favorable for dapagliflozin. And so, these findings should challenge any clinical reluctance to introduce dapagliflozin in patients perceived to be frail. Dr. Greg Hundley: Wow. Carolyn, really interesting. You could see with the diuretic effect in someone that's frail, the potential hesitancy, but very interesting study results in this world of frailty and the use of dapagliflozin. Well, Carolyn, this next study is very interesting and it comes to us from the world of preclinical science that takes a very interesting approach to a scientific question. Now, as you may know, RNA-binding proteins or RBPs are master orchestrators of genetic expression regulation. They regulate hundreds of transcripts at once by recognizing specific motifs, thus characterizing RBPs targets is critical to harvest their full therapeutic potential. However, such investigation has often been restricted to a few RBP targets, thereby limiting our understanding of their function. Carolyn, these investigators led by Dr. Grégoire Ruffenach from UCLA were interested in assessing pulmonary arterial hypertension and they turned to the world of cancer research. Carolyn, in cancer, the RNA-binding protein hnRNPA2B1, and we're going to abbreviate that as A2B1, promotes a pro proliferative anti-apoptotic phenotype. The same phenotype is present in pulmonary arterial smooth muscle cells and is responsible for the development of pulmonary arterial hypertension. However, the A2B1 function that's never really been investigated in pulmonary arterial hypertension. Dr. Carolyn Lam: Oh, Greg, that's not only fascinating, but so beautifully described. Thank you. What did they find? Dr. Greg Hundley: Right, Carolyn. These authors found that A2B1 expression and it's nuclear localization are increased in human pulmonary arterial hypertension, pulmonary arterial smooth muscle cells. Using bioinformatics, they identified three known motifs of A2B1 and all mRNAs carrying them and demonstrated the complimentary non-redundant function of A2B1 motifs as all motifs are implicated in different aspects of the cell cycle. In addition, they showed that pulmonary arterial smooth muscle cells and A2B1 promote the expression of its targets. Additionally, in vivo A2B1 inhibition in the lungs rescued pulmonary hypertension in rats. And so, Carolyn, through the integration of computational and experimental biology, this team study revealed the role of A2B1 as a master orchestrator of pulmonary arterial smooth muscle cells in pulmonary hypertension and that phenotype and its relevance as a therapeutic target in pulmonary arterial hypertension. Dr. Carolyn Lam: Wow, that's super, Greg. Thanks. Shall we go through what else is in today's issue? Dr. Greg Hundley: You bet, Carolyn. There's a Research Letter from Professor Mustroph entitled, “Empagliflozin Inhibits Cardiac Late Sodium Current versus Calcium Calmodulin‐dependent Kinase II.” Dr. Carolyn Lam: There's also an exchange of letters between Doctors Omarjee and Diederichsen regarding vitamin K2 and D in patients with aortic valve calcification: [an] absence of evidence might not be evidence of absence? And finally, there's an On My Mind paper by me and Scott Solomon and it's entitled, “Delivering Therapeutic Efficacy Across the Ejection Fraction Spectrum of Heart Failure.” But let's go on now to talk about the Factor XI inhibitor, shall we, Greg? Dr. Greg Hundley: You bet. Well, listeners, welcome to this feature discussion on October 18th at a very special article today. And we have with us the lead author, Dr. Sunil Rao from NYU in New York City and also our associate guest editor as well as editorialist, Dr. Gregory Lip from Liverpool. Welcome, gentlemen. Sunil, we'll start with you. Can you describe for us some of the background information that went into the preparation of your study and what was the hypothesis that you wanted to address? Dr. Sunil Rao: Yeah, great. Thanks so much, Greg. It's a real pleasure to be here with you. The background of the PACIFIC-AMI study is really rooted in the fact that patients who have acute myocardial infarction are really at risk for recurrent thrombotic events, even after their event. And this risk continues despite the fact that we have evidence based therapies that are really around targeting the platelet as well as aspects of the coagulation cascade. There have been studies that have looked at the use of dual antiplatelet therapy plus an anticoagulant or single antiplatelet therapy plus an anticoagulant. And those studies have shown a benefit. However, their clinical use is limited because of the bleeding risk. Factor XI is an interesting target, because factor XI is likely involved in the amplification of thrombin generation after plaque rupture. But it really doesn't play much of a role in hemostasis. And so, as a target in reducing events after acute coronary syndrome, activated factor XI is a very attractive one. And so, the hypothesis of this study was that a highly bioavailable oral, direct, selective activated factor XI inhibitor called asundexian would be safe and effective in the treatment of patients who experience acute coronary syndrome at reducing adverse events. Now, this is a phase two study, so it really wasn't powered for clinical events. It was really a dose-finding study, so it was really looking at adverse events and sort of bleeding complications. Dr. Greg Hundley: Very nice. Asundexian, a new factor XI inhibitor. And Sunil, can you describe for us your study design and then maybe a little bit more about the study population, how many subjects? Dr. Sunil Rao: Sure. Again, this is a phase two study. It was a randomized, double-blind, parallel-group design where patients, who were admitted with acute coronary syndrome were randomized to three different doses of asundexian and or placebo in a one-to-one to one-to-one fashion. Patients who met criteria for enrollment were: patients who were admitted with a diagnosis of acute MI; if they were older than or equal to 45 years of age; they were hospitalized in acute coronary syndrome that did not occur in the context of revascularization, so it was not a type 4 event; and they were planned to be treated with dual antiplatelet therapy after hospital discharge. Dr. Greg Hundley: Sunil, thank you for describing this very interesting study design. Now, how many subjects did you include and could you just describe for us the study population? Dr. Sunil Rao: We had a total of 1,601 patients that were randomized at 157 centers in 14 countries between June 2020 and July 2021. And in order to be eligible for enrollment into the study: patients had to be admitted with a diagnosis of acute MI, they had to be greater than or equal to 45 years of age, and be hospitalized with that acute MI that did not occur in the context of revascularization, so type 4 MIs were excluded. The other inclusion criteria was that they had to be planned to be treated with dual antiplatelet therapy after hospital discharge. Now, we allowed randomization up to five days after hospital admission and randomization occurred after patients were clinically stabilized and any planned PCI was performed. We included both patients with STEMI as well as non-ST segmental elevation ACS, but we capped the number of patients with STEMI that were included to no more than 50%. Now, the main exclusion criteria were things that you would expect for a phase two trial. Obviously, hemodynamic instability at the time of randomization, active bleeding or bleeding dialysis, severe renal dysfunction, planned use of full-dose anticoagulation. Dr. Greg Hundley: Very nice. And so, we have several doses of this new factor XI inhibitor. Describe for us your study results? Dr. Sunil Rao: Again, this was a phase two trial that was really looking at safety and adverse events as you would expect. The study groups were pretty balanced across all of the dosing arms. When we looked at the pharmacokinetic and pharmacodynamic data, we found something really interesting, which was that there was a dose relationship between the dose of asundexian and the factor XIa activity. Factor XIa is activated factor XI. The higher the dose, the more suppression of factor XI activity. In fact, the highest dose nearly eliminated factor XI activity. The drug clearly works in the way that it was intended. Now again, the clinical data, it wasn't powered for clinical data. But when we look at the bleeding results, we found that there was in fact an increase in bleeding as the dose of asundexian increased. The overall rate of bleeding in the highest dose of asundexian was in 50 milligrams was 10.5% with type 2 or 3 or 5 BARC bleeding, a placebo is about 9.02%. Again, the efficacy outcomes, very, very low rates of overall events. Again, not powered to show a difference. Essentially, very similar across all the arms. Dr. Greg Hundley: And did you find the same results for the men and the women? And what about older individuals and younger individuals? Dr. Sunil Rao: Yeah. We did look at some subgroups. And you had to be a little bit cautious because again, the trial itself is relatively small. I mean, we didn't notice any significant patterns across these subgroups. And the overall interaction p-values were really non-significant. But I think what this does show is like a phase two trial that the drug works as in the way that it's intended. Overall, safety was as expected. And I think it really sets up data for a larger study. Dr. Greg Hundley: Well, listeners, what a fantastic presentation. And now, we're going to turn to our guest editor and editorialist, Dr. Gregory Lip from Liverpool. Greg, I know working for circulation, you have many papers come across your desk. What attracted you to this particular paper? And then maybe secondly, can you help us put the results of this study in the context of other studies that have been evaluating these factor XI therapies? Dr. Gregory Lip: Thanks, Greg. Well, I think this is an important paper, because it is a phase two trial with a novel, orally bioavailable inhibitor factor XI. And this is intriguing because factor XI efficiency in humans and experimentally in animals is associated with a reduced risk of thrombotic events like stroke or venous thromboembolism. But spontaneous bleeding is rare and also bleeding in response to trauma or surgery is much milder. Really it's the holy grail of trying to get an anticoagulant that reduces thrombosis but doesn't cause an excess of bleeding. Now, this was the quest with different anticoagulants. And I think it was very exciting to see this particular paper in the patients who've had an acute coronary syndrome, because there was a lot of interest in the use of anticoagulants, particularly in combination with antiplatelet therapy from trials such as ATLAS and COMPASS, where there was certainly a reduction in adverse cardiovascular events. But a downside with those drugs and when using combination, was an excess of bleeding by the combination of the available anticoagulants now plus antiplatelets. The factor XIs agents offered the possibilities we might have combination therapy to reduce cardiovascular events but not causing an excess of bleeding. Dr. Greg Hundley: Well, listeners, what a wonderful discussion that we've had here. Let's circle back with both individuals. Sunil, we'll start with you. What do you see as the next study to really be performed in this sphere of research? Dr. Sunil Rao: I think that factor XI is a very attractive target in patients with acute coronary syndrome. Again, the rationale for why we did this phase two trial was to show that inhibition of activated factor XI should result in a low rate of ischemic events without a significant increase in bleeding. This phase two trial was really to try and decide which doses result in potent inhibition of factor XIa and potentially which doses should be carried forward into a larger study. What we found in the PACIFIC-AMI trial was that the doses of asundexian and the factor XIa inhibitor were very, very well tolerated with a low rate of adverse events. It resulted in a dose-dependent near complete inhibition of factor XIa activity without a significant increase in bleeding and a low rate of ischemic events. I think, again, it's a very attractive target in patients with ACS and this really provides support for a larger adequately powered clinical trial in patients with acute coronary syndrome that is really looking at clinical events such as MACE as well as bleeding. Dr. Greg Hundley: And Greg as an editorialist, what did you see with this paper? Maybe some unanswered questions that we'd like to pursue further? Dr. Gregory Lip: Well, I think this does raise a lot of questions in the sense that it'll be interesting because as a phase two trial, it's a relatively moderate sized trial. It's not like a phase three large outcome trial and phase two trials also testing different doses of the novel agent. We need to see the definitive phase three trial and to look at the magnitude of benefit versus potential for bleeding if in the large phase three trial and obviously, the net clinical benefit and importantly are some of the subgroups: ST elevation, myocardial infarction, undergoing primary PCI, for example, those with renal impairment. And I think particularly intriguing would be looking at the patients in this scenario who get the new antiplatelet drugs such as ticagrelor and prasugrel. And the reason I say that is what we have with warfarin or Coumadin and from the current DOACs or NOACs, depending on the risk side upon. We refer to them, that's the direct oral anticoagulants or non-vitamin K antagonist or anticoagulants. Well, if you give a more potent antiplatelet like prasugrel or ticagrelor, the risk of bleeding not surprisingly is higher. Hence, the guidelines recommend that if you use an anticoagulant or a DOAC, you use it with a P2Y 12 inhibitor clopidogrel as opposed to the more potent ones. If this new class of drugs, the factor XI inhibitors can work well in combination with one of the more potent antiplatelets without causing an excessive bleeding, again, this is going to be a substantial advance. Well, with these new class of anticoagulants, will be really interesting to see the phase three trials when applied to other chronic conditions. For example, stroke prevention and atrial fibrillation. And the other category of patients would be those who've had an embolic stroke of uncertain source or ESUS or in old terminology cryptogenic stroke. With the ESUS group of patients, they're currently treated with aspirin because the trials which tried a NOAC or DOAC, they were not showing a positive result. They'll be interesting again with the factor XI inhibitors, whether we are going to see this benefit with the reduction in recurrence stroke with no excessive bleeding. Dr. Greg Hundley: Very nice. Well, listeners, we want to thank Dr. Sunil Rao from NYU in New York City and Dr. Gregory Lip from the University of Liverpool for bringing us this study highlighting that in patients with recent acute myocardial infarction, three doses of asundexian when added to aspirin plus a P2Y 12 inhibitor resulted in dose-dependent near complete inhibition of factor XIa activity without a significant increase in bleeding and a low rate of ischemic events. And certainly, the data from this study support the investigation of asundexian at a dose of 50 milligrams daily in an adequately powered clinical trial of patients following acute myocardial infection. Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week On the Run. This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Michelle O'Donoghue and Associate Editor Parag Joshi as they discuss the article "Long-Term Evolocumab in Patients With Established Atherosclerotic Cardiovascular Disease." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts, Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor and Director of the Poly Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, very interesting feature this week. Evolocumab, another application for that in patients with established atherosclerotic cardiovascular disease. But before we get to that feature discussion, how about we grab a cup of coffee and discuss some of the other very interesting articles in this issue? Dr. Carolyn Lam: Oh, I'd love that. And I'd like to go first, because Craig, have you heard of hybrid debranching repair? I know, I know. I had that same look, and can I tell you about it? Because I found it so interesting. Dr. Greg Hundley: Absolutely. Dr. Carolyn Lam: Now, the management of complex aortic aneurysmal disease involving the visceral vessels is challenging due to its very high morbidity and mortality. After four decades of experience in open repair, only a few centers worldwide report laudable results. And numerous factors limit total endovascular repair, including the access to devices, experience in deploying them, and several anatomical restrictions. So, hybrid debranching procedures were introduced for those patients who are unfit for the open or endovascular excluded patients. And while these have been developed, small series have only been done and revealed a wide range of short term results. So, today's paper is very important, and it's from Dr. Oderich from UT Memorial Herman Texas Medical Center and colleagues. It's a large multi-institutional study, which contains the five year outcomes in 200 patients offering greater clarity in the usefulness and limitations of these hybrid debranching repair procedures. What they found was that hybrid aortic debranching had a low early mortality when done in lower risk patients, but mortality remained very elevated in high risk patients. And so, this suggests that deep branching could be a good alternative in patients adequate for traditional open repair, although pulmonary complications are quite common. The bypass grafts to the visceral vessels had very good patency with a five year primary patency of 90%. Permanent spinal cord injury occurred in 6%, suggesting that deep branching in experienced centers may offer outcomes comparable to centers of excellence for open thoracoabdominal aortic aneurysm repair. Dr. Greg Hundley: Wow, Carolyn, very nice and so beautifully explained. Dr. Carolyn Lam: You know what, Greg? I'm on a roll and I'd like to tell you about one more, this time a preclinical study. First, a little bit about the background. You see, transplantation with pleuripotent stem cell derived cardiomyocytes, as we know, represents a very promising therapeutic strategy for cardiac regeneration. We even have first clinical studies in humans, but yet little is known about the mechanism of action underlying graft induced benefits. So in this paper from Dr. Weinberger from University Medical Center Hamburg in Germany and colleagues, they explored whether transplanted cardiomyocytes actually actively contribute to heart function by injecting these cardiomyocytes with an optogenetic off on switch in a Guinea pig cardiac injury model. Dr. Greg Hundley: Wow, Carolyn, this is so interesting. So what did they find? Dr. Carolyn Lam: So, light induced inhibition of endo-grafted cardiomyocyte contractility resulted in a rapid decrease in left ventricular function in about 50% of the animals that was fully reversible with the offset of photo stimulation. So in conclusion, this optogenetic approach demonstrated that transplanted cardiomyocytes can actively participate in heart function, supporting the hypothesis that the delivery of new force generating myocardium can serve as a regenerative therapeutic strategy. Dr. Greg Hundley: Oh wow, Carolyn. That was just fascinating. Such incredible preclinical science in our journal. Well, Carolyn, this next paper comes to us from the world of myocarditis. And Carolyn, it involves a population based cohort of 336 consecutively recruited patients with acute myocarditis enrolled in both London and Maastricht. And the authors, led by Dr. Sanjay Prasad from Royal Brompton Hospital, investigated the frequency and clinical consequences of dilated cardiomyopathy and arrhythmogenic cardiomyopathy genetic variants in this population based cohorts of patients with acute myocarditis. Now, Carolyn, all participants underwent targeted DNA sequencing for well characterized cardiomyopathy associated genes and their comparison to healthy controls, of which they had 1,053 that were sequenced on the same platform. Case ascertainment of their outcomes in England was assessed against their national hospital admission data, and the primary outcome was all cause mortality. Dr. Carolyn Lam: So what did they find, Greg? Dr. Greg Hundley: Right, Carolyn. So these authors identified for dilated cardiomyopathy or arrhythmogenic cardiomyopathy associated genetic variants in 8% of patients with acute myocarditis. This was dominated by the identification of desmoplakin truncating variants in those with normal LVF, and then titin truncating variants in those with a reduced LVF. So Carolyn, importantly, these variants have clinical implications for treatment, risk stratification, and family screening. Genetic counseling and testing would be considered in patients with acute myocarditis to help reassure the majority of individuals that don't have one of these genes, while improving the management of those that do have one of the underlying genetic variants. Very interesting findings from the world of myocarditis. Dr. Carolyn Lam: Great. And a great clinical take home message. Thank you, Greg. Well, this next paper sought to investigate the influence of age on the diagnostic performance of cardiac troponins in patients presenting with suspected myocardial infarction. Dr. Atul Anand from the BHF Center for Cardiovascular Science and University of Edinburgh and colleagues did this by performing a secondary analysis of the high stakes stepped wedge cluster randomized control trial that evaluated the implementation of a high sensitivity cardiac troponin ISA in consecutive patients presenting with suspected acute coronary syndrome. Dr. Greg Hundley: Oh wow. Carolyn. Super interesting, and very applicable clinically. So what did they find here? Dr. Carolyn Lam: In older patients presenting with suspected MI, the majority of cardiac troponin elevations are explained by acute or chronic myocardial injury or type two MI. The specificity and positive predictive value of high sensitivity cardiac troponin to identify myocardial infarction decreases with age and is observed, whether applying sex specific or age adjusted 99th percentile diagnostic thresholds or a rolling threshold for the triage of patients at high probability of myocardial infarction. Serial troponin testing incorporating an absolute change in troponin concentration increased the discrimination for myocardial infarction in older adults. Dr. Greg Hundley: Oh wow, Carolyn. Such clinically applicable findings in this particular study, particularly when managing our aging population. Well, Carolyn, how about we discuss some of the other articles in this issue. And there's a very nice In-depth piece by our own Sami Viskin entitled “Arrhythmogenic Effects of Cardiac Memory.” And then, there's an exchange of letters by Drs. Giannitsis and Mueller regarding the article, “Unexpected Sensitivity Issue of Three High Sensitivity Cardiac Troponin I-Assays in Patients with Severe Cardiac Disease and Chronic Skeletal Muscle Diseases.” Dr. Carolyn Lam: Nice. There's also a Research Letter by Dr. Szendroedi on “Impaired Mitochondrial Respiration in Humans with Prediabetes: A Footprint of Prediabetic Cardiomyopathy.” And there's a CV case series by Dr. Kalra on very high cholesterol mimicking homozygous familial hypercholesterolemia. Interesting case. Well, I suppose that wraps it up. Let's go on to the feature discussion, shall we, Greg? Dr. Greg Hundley: You bet. Evolocumab. Welcome listers to this feature discussion on October 11th, and we're very fortunate today. We have with us Dr. Michelle O'Donoghue from Brigham Women's Hospital and Dr. Parag Joshi from UT Southwestern, the Associate Editor for this paper. Well, Michelle, can you describe for us some of the background information that went into the preparation of your study, and then what was the hypothesis that you wanted to address? Dr. Michelle O'Donoghue: Sure. Happy to do so, and thank you for having me. So by way of background, the Fourier study, which was previously published in the New England Journal, compared Evolocumab to placebo in 27,000 plus patients with established atherosclerotic cardiovascular disease, and Evolocumab significantly reduced the risk of major adverse cardiovascular events. But, the follow up duration was relatively short. Median follow up was 2.2 years. So this was now an open label extension study to Fourier known as the Fourier OLE study that allowed an additional median follow up time of five years, during which time all patients were now treated with open label Evolocumab. T. He primary hypothesis that we were testing in this extension study was primarily to look at long term safety. We had limited data to really assure us of the safety of PCSK9 inhibitors over the course of several years. And so, safety was the primary hypothesis that we were testing, but also of course of key interest, during the parent Fourier study, we know that the benefit for cardiovascular risk reduction appeared to grow over time. So this was also an opportunity to see that pattern and to see whether or not there was in fact legacy effect for patients who were treated earlier with Evolocumab versus placebo. Dr. Greg Hundley: Very nice, Michelle. And so, sounds like we have a substudy of the Fourier trial. Can you describe for us a little bit more, for this substudy, your study population and your study design? Dr. Michelle O'Donoghue: Sure. So the patients enrolled in the open label extension were a subset of those who participated in the parent study. So as I previously mentioned, more than 27,000 participated in Fourier. It was a global study. For the open label extension, it was more than 6,500 patients who participated, and those were patients who were at sites in Europe and United States. And so, those patients were then followed on average for a meeting of five years. So that means that all together, patients who had been randomized to Evolocumab in the parent study had potentially more than eight years of drug exposure for us to examine safety. Dr. Greg Hundley: Very nice. And so, what did you find? Dr. Michelle O'Donoghue: Well, first, looking at the first hypothesis of safety, we saw no evidence that there was any increased risk of any adverse events of interest when it comes to PCSK9 inhibitors as a drug class, or achieving very low levels of LDL cholesterol. So there was no uptick in terms of neurocognitive events, the risk of diabetes. We do know that there was an increased risk of injection site reactions with the PCSK9 inhibitors, but not one that appeared to persist over time. So first was the safety, but importantly, I think that the more interesting results perhaps were those for MACE, for cardiovascular risk reduction. So we saw, even though all patients were being treated with open label Evolocumab during the extension phase, the benefit that was seen during the parent study persisted. So there was a 15% reduction in the primary outcome, a broad composite of cardiovascular events. There was also a 20% reduction in the triple composite of cardiovascular death, MI, or stroke. And then perhaps of the most interest to your listeners is that there was a 23% reduction in cardiovascular mortality, and that was not something that was seen in the parent study. It really took time for that mortality benefit to emerge. Dr. Greg Hundley: Very nice. Michelle. Just a couple quick clarification points. Did you see these effects in both men and women? And then was there any impact of age on those results? Dr. Michelle O'Donoghue: Great questions. Some of those subgroup analyses are still ongoing, but no, we did not see any evidence of effect modification at first pass. But again, we'll be continuing to dig into all potential subgroups. Dr. Greg Hundley: Very nice. Parag, I know you have many papers come across your desk. What attracted you to this particular manuscript? Dr. Parag Joshi: Yeah, thanks. And congratulations again, Michelle. It's a really phenomenal study, and the findings, as you highlighted, are just really impactful for the field. I think for our journal at circulation, this is a really high impact finding in terms of extending out, giving us a rigorous way to look at long term follow up for people on PCSK9 inhibitors and really reassure that there is safety there. And as you highlighted, a sustained reduction in LDL cholesterol, other compounds in the space, Bococizumab in particular, that there were induced antibodies against the monoclonal antibody, and that sustained response was not there. So I thought that was also really reassuring, that over the course of eight years, we see sustained LDL reduction. And with that, really reaffirming the idea that the longer you can reduce LDL, there's an associated reduction in events. And as you highlighted, the initial Fourier, there was some question about why there wasn't a CV death mortality signal while there was in the Odyssey outcome study and slightly different patient populations of course, but just really needed more time to start to tease that out. So all of this, I think this is the first that we're seeing this kind of long-term data on this impactful class of medications that really made this a fantastic manuscript for us at Circulation. Dr. Greg Hundley: Wow. Boy, Parag, I don't know that you could have stated that any better. So Michelle, looking forward, what is your group thinking? And then maybe just as your comment on the field in general, what do you think is the next study or series of studies that needs to be performed in this sphere of research? Dr. Michelle O'Donoghue: Well, I think he started to touch upon the areas of interest to us, is that I think that there are still many opportunities to answer more questions even within this existing data set. In particular, there was a dedicated neurocognitive substudy that was built into the parent study. And we also have that now through the extension period. So, that was a sort of more rigorous assessment of neurocognitive outcomes. And so, that's another analysis that we're going to be pursuing in the near future and I think is of potential key interest. And then beyond that, I think that the PCSK9 inhibitor class in general is just so interesting. There are additional compounds that are under study, such as small interfering RNA, so different mechanisms of getting to the PCSK9 protein. And I think it'll be reassuring to see whether or not they are consistent results, regardless of how you lower PCSK9, whether it translates into similar types of clinical benefit. So I think it's an exciting field. And then stay tuned. I think there'll be more to come. Dr. Greg Hundley: Parag, do you have anything to add? What do you see really as the next series of studies that might be performed here in this area of research? Dr. Parag Joshi: Yeah, I think Michelle hit the nail on the head that seeing confirmatory evidence here would be great. And then really, what's so exciting about this space is there's so much interest in ways to address this protein, including gene editing, vaccination against it. And now you're getting the necessary evidence that, hey, you can really suppress these levels in patients for years without concerning safety signals, at least from what we've seen so far. So that's more excitement as to long term ways to address cardiovascular risk. Dr. Greg Hundley: Wow. Well, listeners, we've been very fortunate today to have with us Dr. Michelle O'Donaghue from Brigham and Women's Hospital, and Dr. Parag Joshi from UT Southwestern as the Associate Editor of Circulation to really bring us these exciting results, highlighting that long term LDL-C lowering with Evolocumab was associated with persistently low rates of adverse events over eight years that did not exceed those observed in the original placebo arm during the parent Fourier study, and led to further reductions in cardiovascular events compared with delayed treatment initiation. Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join authors Jonas Oldgren and Signild Åsberg as they discuss the article "Early Versus Delayed Non–Vitamin K Antagonist Oral Anticoagulant Therapy After Acute Ischemic Stroke in Atrial Fibrillation (TIMING): A Registry-Based Randomized Controlled Noninferiority Study." Dr. Carolyn Lam: Welcome to Circulation on The Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Poly Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Today's featured paper is a very important discussion, and in fact, the first study to compare early versus delayed NOACs after acute ischemic stroke in patients with atrial fibrillation. The timing study. You're not going to want to miss this, but you're going to have to wait for it, because we're going to discuss all the papers in today's issue. Can I start, Greg? Because I want to start, or is it too early to start with a Greg quiz? With the quiz question being, what is cell-free DNA? Dr. Greg Hundley: Oh, thank you Dr. Lam. I really appreciate your wonderment into the world of preclinical science. So something maybe short DNA fragments, but I'm not sure. Dr. Carolyn Lam: Aw, you're absolutely right. It's circulating DNA fragments predominantly from mononuclear zones that represent cell injury and/or turnover. So what we know is elevated total cell-free DNA concentration has been associated with worse prognosis in a variety of conditions such as sepsis, trauma, malignancy. In addition, and this may be where a lot of us have heard of cell-free DNA, it's become clinically relevant as a noninvasive marker of solid organ transplant rejection as well as a tool for genotyping and surveillance in oncology. However, in today's paper, given the parallels in the pathogenesis of pulmonary artery hypertension, two of the diseases I've talked about before that are characterized by increased cell proliferation and turnover, like the cancers and inflammatory mediated tissue injury. Now this particular study sought to determine if plasma cell-free DNA concentrations were elevated in pulmonary artery hypertension, and if those levels would correlate with disease severity or predict outcomes. Dr. Greg Hundley: Oh wow, Carolyn, this sounds really informative. So what did they find? Dr. Carolyn Lam: Well, this study from corresponding authors, Dr. Solomon from NIH Clinical Center and Dr. Agbor-Enoh from NHLBI in Bethesda and their team found that circulating cell-free DNA is elevated in patients with pulmonary arterial hypertension compared to healthy controls. In two independent PAH patient cohorts, cell-free DNA concentrations increased with severity of disease and predicted transplant free survival in the larger of the two cohorts. Interestingly, methylation patterns revealed increased cell-free DNA originating from biologically plausible sites including erythrocyte progenator and myeloid lineage inflammatory cells, vascular endothelium, and cardiac myocytes. So the implications are that in pulmonary arterial hypertension, cell-free DNA concentrations could serve as a non-invasive biomarker of underlying disease activity, may add prognostic value to currently use risk scores, and may provide a unique noninvasive window into its pathogenesis. Dr. Greg Hundley: Wow, Carolyn. So another interesting technique and pathophysiologic study highlighting the utility of circulating cell-free DNA. Wow. Well, Carolyn, how about I start in with my first study and it comes to us from the world of clinical science and refers to the paradise MI echocardiographic substudy. So Carolyn, the prospective RNE versus ACE inhibitor trial to determine superiority in reducing heart failure events after myocardial infarction. So the Paradise MI echo study tested the effect of Sacubitril/Valsartan compared to Ramipril on LV function and adverse remodeling following high risk acute myocardial infarction. So this substudy included 544 Paradise MI participants that underwent echocardiography at randomization, and then again later at eight months. Patients were randomized within a half to seven days of their presentation with their index, myocardial infarction, to receive a target dose of Sacubitril/Valsartan of 200 milligrams or Ramipril five milligrams twice daily. Dr. Carolyn Lam: All right. So the Paradise MI echo substudy, what did they find? Dr. Greg Hundley: Right Carolyn, so treatment with Sacubitril/Valsartan compared to Ramipril following acute myocardial infarction did not result in changes in left ventricular ejection fraction or left atrial volume at eight months. Patients randomized to Sacubitril/Valsartan had less LV enlargement and greater improvement in filling pressure, and thus there are new insights here in that treatment with Sacubitril/Valsartan compared to Ramipril early following acute myocardial infarction may beneficially impact LV size and diastolic properties possibly due to reductions in LV filling pressure. Dr. Carolyn Lam: Oh, very nice, Greg. Thank you. Another clinical study here, and this time a paper aimed to evaluate the influence of sex on the effects of empagliflozin in patients with HFpEF enrolled in the Emperor Preserved trial. Dr. Greg Hundley: Ah, Carolyn, two of your favorite things, sex differences and SGLT2 inhibitors. So Carolyn, remind us, what did Emperor Preserved show us? Dr. Carolyn Lam: Ah, so Emperor Preserved studied the sodium glucose cotransporter 2 or SGLT2 inhibitor empagliflozin in patients with HFpEF, which is an ejection fraction above 40%, and showed a significant reduction in the risk of cardiovascular death or heart failure hospitalization. In the current paper, corresponding author Dr. Javed Butler from University of Mississippi Medical Center and colleagues found that empagliflozin reduced the risk of the primary outcome of cardiovascular death or hospitalization for heart failure to a similar degree in both women and men with HFpEF irrespective of baseline left ventricular ejection fraction. Empagliflozin produced comparable benefits for the pre-specified secondary outcomes of total heart failure hospitalizations, cardiovascular death, and all-cause mortality, as well as physiologic measures and health status. The pattern of the effects of empagliflozin and HFpEF in both sexes in EMPEROR- Preserved stands in contrast to the influence of sex on the response to neprilysin inhibition. So very interesting paper. I encourage everyone to pick it up, of course, because it's two of my favorite topics. Dr. Greg Hundley: Very nice, Carolyn. Well, my next paper comes to us from the world of pre-clinical science, and it's from Dr. Chunyu Zeng from Diping Hospital, the third military medical university. Carolyn, adverse environmental exposure during the prenatal period can lead to diseases in offspring, including hypertension. Now whether or not the hypertensive phenotype can be trans-generationally transmitted is really not new. Dr. Carolyn Lam: Wow, that's interesting. So what did this paper find? Dr. Greg Hundley: Carolyn, this was really interesting. So these authors in a rat model, they found that prenatal lipopolysaccharide exposure can impair the ability to excrete a salt load and induce hypertension from the first to the third generations, with the fourth and fifth generations inducing salt-sensitive hypertension. And Carolyn, really interestingly, and based on these findings, they treated lipopolysaccharide exposed pregnant rats with the reactive oxygen species scavenger temple, which successfully prevented hypertension in the first-generation offspring and the transgenerational inheritance of hypertension. So Carolyn, these findings show that adverse prenatal exposure induces transgenerational hypertension through an epigenetic regulated mechanism. And these findings identify potentially preventive and therapeutic strategies for this form of generationally transmitted hypertension. Really interesting. Dr. Carolyn Lam: Wow, that sounds wild. Very, very interesting. Well, let's go through the other things that are in today's issue. There's a research letter by Dr. Moayedi on anteroposterior pacer pad position is more likely to capture than anterolateral for transcutaneous cardiac pacing. Dr. Greg Hundley: Great, Carolyn. And I've got a research letter from Professor Porrello entitled, “Defining the Fetal Gene Program at Single Cell Resolution in Pediatric Dilated Cardiomyopathy.” And then lastly, there's an ECG Challenge from Dr. Chen entitled, “A Shark Thin Electric Cardiogram in the Intensive Care Unit.” Well Carolyn, how about we get onto that featured discussion and learn more about non-vitamin K antagonists after acute ischemic stroke? Dr. Carolyn Lam: Yep. In patients with EF, here we go. Today's feature discussion is all about atrial fibrillation, how it's a risk factor for stroke, but also about how we've never known really how soon after an acute stroke can we start oral anticoagulation to prevent recurrent strokes? Today we're going to talk about the timing study. It's the first randomized controlled study to evaluate the efficacy and safety of initiation of treatment with NOACs within 10 days of acute ischemic stroke in patients with atrial fibrillation. Wow. What an exciting study, and also how exciting that we have two co-first authors. We have Dr. Jonas Oldgren and Dr. Signild Åsberg from Uppsala University in Sweden, and this represents a partnership between neurology and cardiology. I mean really unique in many aspects as well as the way this study was performed, which is truly, truly a feat in itself. May I ask you both please to tell me the story of how this study came to be in the first place? Dr. Signild Åsberg: Well, we like to mention the late Professor Gesteruen student who actually was the first to bring this question to the table. Together we talked with the cardiology department and Jonas Oldgren to see if we can collaborate to solve this important question for us that works with stroke patient, because it's on a weekly or even a daily basis, troublesome question. Dr. Jonas Oldgren: My background is as a cardiologist and professor of coagulation research. I've been very interested in anticoagulants, antithrombotic treatments, and had the pleasure and privilege to be part of the development of the novel oral anticoagulants. And in all those pivotal trials, we excluded patients with a recent stroke at least seven days from the stroke, sometimes even 30 days from the acute stroke we excluded them from the studies. So when we found the exciting results with at least as good efficacy as warfarin and at least as good safety as warfarin and the tremendous reduction in intracerebral or intracranial bleeds, that was a finding which was not evaluated in acute stroke patients with atrial fibrillation. And when Signild approached me with this idea, I said, "Well this is absolutely a very important question and why hasn't it been resolved earlier?" And the problem is, of course, that these are patients who are in a sensible setting earlier after the acute ischemic stroke, and when are we able to safely start an effective treatment? Dr. Carolyn Lam: Oh, I couldn't agree more with you about how important that is. I mean, when we have an acute stroke patient, we just don't know whether we should start the NOAC early or delay it and we definitely need that evidence gap filled. But I'm also so intrigued with the way you did it with the Swedish Stroke Register. I mean, what a powerful way to look at important questions like this. Could you tell us a bit more about the method used? Dr. Jonas Oldgren: Yeah, so in cardiology we started rather early by using our national health registries for doing randomized controlled trials. We did a lot of observational studies in our registries, both in stroke and in cardiovascular medicine, otherwise in every other area of medicine. But in the end we realized that we could at best be hypothesis generating, but we still needed to add randomized controlled studies to have the last piece of the puzzle to provide good evidence. And then we ran a lot of studies in cardiologists, especially in myocardial infarction patients, by just adding to simplify, by adding a randomization module, and then follow the patients in the registries because we know that we have high quality data in the registry. For instance, in the stroke registry. So we anyway collect every important data on each and every patient in the register. So by adding a randomization module, we can facilitate the conduct of a clinical study. Dr. Carolyn Lam: Wow. The way you say it, you make it sound so simple, but I can tell you what you have there in Sweden is like the envy of the whole world, and everybody's thinking about how to do a registry based trial like that. So maybe after you tell us the results, you could also share a little bit of how difficult and challenging it can be as well. But would either of you like to share the results? Dr. Signild Åsberg: Well, the major result from our trial is that initiating NOAC within four days is non-inferior to starting in a delayed phase of up to 10 days. So that's our key finding. But equally important is that we didn't have any patients explaining as symptomatic and terrible hemorrhage, and that is extremely good news for us who worked with these patients. Dr. Carolyn Lam: That is such an important message. The early initiation was non-inferior. Could you expand on non-inferior in terms of what primary outcome? Dr. Jonas Oldgren: Yeah, so the primary outcome was really a clinically important outcome we think, both from the cardiac perspective but also from stroke specialists. So we had a combination composite of symptomatic intracerebral hemorrhages, ischemic strokes and death. And this is what matters to patients and to doctors. We would like to avoid strokes, and it doesn't matter if it's an ischemic stroke or if it's a hemorrhagic stroke. We would like to avoid them. And of course we would not like to have an increased mortality as well. So it's a relevant endpoint. And when we designed the study, the main drug used was warfarin, and there we knew that there was a lot of hemorrhagic transformations and a lot of intracerebral hemorrhages. So we designed the trial to look at these three endpoints to prevent ischemic strokes, but to avoid hemorrhagic strokes. And that is why we choose to have a non-inferiority design, because we also have the advantage of starting early if we can make the decision to start with the stroke specialists sometimes in collaboration with the cardiologist, and then we can have the patient step down unit earlier if the treatment is already started. So that was the choice of a non-inferiority design. We of course also tested for superiority, but unfortunately we didn't meet that superiority testing endpoint. But as Signal mentioned, I think thrilling results is to have no symptomatic intracerebral hemorrhage in any of the groups. That really speaks in favor of the safety of this drug or these drugs that we used, but also the concept to start early. We can also note that we had some ... I mean there were numerically lower rates of both ischemic strokes and deaths in the early group, albeit not meeting the significance for superiority, but it's important. And as we see also the events tend to occur very early. So we really gain with treating our patients earlier with this intervention. Dr. Carolyn Lam: Oh indeed. And to all the listeners, do pick up the paper because if you look at the Kaplan-Meier curves, they're really impressive, exactly like you said, numerical differences, although the trial did demonstrate non-inferiority and could not demonstrate the superiority. But have a look at those figures. And if I could just clarify the comparator arm, notice that we've been saying NOACs, not a particular NOACs. So could you expand on that a bit? Dr. Signild Åsberg: We used all the four NOACs that we have in Sweden, so that was to the physician's discretion to choose between them. So that was not a part of the randomization. So we only randomized the timing to the early phase or the delayed phase. Dr. Carolyn Lam: I love that. And then if you could please educate the cardiologist in me, please. There are symptomatic intracerebral hemorrhages, and then there are all kinds of little things that you can pick up if you image the brain and hemorrhagic transformation and microbleeds and all these things. So I think one of the things here was their systematic imaging and does it matter? Could you teach us a little bit more about these different types of bleeds? Dr. Signild Åsberg: We did not have a systematic imaging, but in Sweden that is performed mostly by CT on admission. So that was for all patients. And then on events, the imaging was performed and reported through the registry. And yes, there were hemorrhagic transformation actually in three patients, two in the early phase, and one in the delayed phase, but only one before day 10. So all blood that was seen on imaging was reported, but we used symptomatic criteria from the stroke severity scale. Dr. Carolyn Lam: Thank you. That's a good clarification. And then the study aimed for a larger number, and here perhaps if either of you could tell us the story, the struggles, and how you ended up with these beautiful results. Dr. Signild Åsberg: Yeah, struggle is the word. It was troublesome and we had long talks. So why was this happening? Why didn't science recruit more? But I think one issue might have been that NOACs had been on the market for a while once we started, and even the stroke physicians were getting used to it and had trouble not to start. Before the timing study started, we did a observational pre-timing study just to see how we were doing in Sweden at this stage. Because we didn't really know that. We know that a lot of patients were discharged with oral anticoagulation, but we didn't really know when they started. And so by that study we could see that in median time to initiation was five days, already before the timing study. So one thought was that this was for some physicians then had to delay their start. They were getting used to start early. So that could have been one explanation. Dr. Jonas Oldgren: And of course there has been a lot of observational studies looking at the safety of NOACs or other oral anticoagulants in the early setting after acute ischemic stroke in patients with atrial fibrillation. And of course with the evidence from such studies, albeit observational doctors felt perhaps more confident starting very early despite the lack of evidence from randomized control trials. So we had the opportunity to follow those patients as well in the stroke registry. Every patient with an acute stroke in Sweden attending a stroke unit is registered. So we have in the supplement of the paper in circulation, we have observational data from the centers participating in stroke, but patients not randomized in the timing study. And we also have observational data from all stroke centers in Sweden. So we can see that many start very earlier with NOACs based on observational data, based on experiences. And perhaps we're more and more reluctant to randomize the patient in the study because as Signal says, that means there is a 50% chance of delayed treatment by randomization. And when we started this study, there were no evidence from randomized controlled trials within the first 14 days. But while running the study for a couple of years, you start to believe that there seemed to be safety because no one saw any symptomatic intracerebral hemorrhage. And we discussed that, of course, at investigative meetings that this seemed to be a very good treatment, which is bad for running a clinical study, but it's of course good for the patients. Dr. Carolyn Lam: Interesting. So echo points kind of may have shifted a little bit even during the course of the trial. So just thank you so much all the more. Thank you for seeing this to completion in the sense of a beautiful manuscript with very meaningful results. If I could ask you both to each summarize just very quickly what the take home message is for clinical practice from neurologist's point of view and cardiologist's point of view? Dr. Signild Åsberg: Yeah, what I would say, it seems both safe and reasonable to initiate NOAC earlier after an acute ischemic stroke. So I think that's the key take home message that really to consider the acute secondary prevention. Dr. Jonas Oldgren: I may bring that from another perspective. I think when there's lack of data in collaboration, we can do a lot. So in this case, we had a great collaboration in the student committee, cardiologist and stroke specialists collaborating to run such a study. And we are extremely grateful for all the sites and all the investigators at the sites participating in the study. And then of course grateful to circulation for publishing it because we are very proud of this study. Dr. Carolyn Lam: And we are proud to be publishing this. So ladies and gentlemen, you heard it right here in Circulation On The Run. Remember this is about early versus delayed initiation of NOACs in patients after an acute stroke who also have atrial fibrillation. And this is a very, very, I think, important study that fills an important evidence gap. We're so grateful to both of you for being here to discuss it, and to the audience for listening today. You've been listening to Circulation On The Run. And don't forget to tune in again next week. Dr. Greg Hundley: This program is Copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit AHAjournals.org.
Advancements in cardiology are moving quickly as technology makes cardiovascular health more accessible. More tools are becoming available so that individuals can monitor their own health, without as many doctors' visits. So, what is next? Listen as our guests Dr. Carolyn Lam, a senior cardiology consultant and director of women's heart health at the National Heart Centre Singapore, and Dr. Richard Nkulikiyinka, a vice president at Bayer and head of clinical development and operations for the therapeutic areas of cardiology, nephrology and pulmonology talk about the future of cardiology, AI and cardiovascular health.
This week, please join authors Hanna-Kaisa Nordenswan and Jukka Lehtonen, as well as Associate Editor Mark Link as they discuss the article "Incidence of Sudden Cardiac Death and Life-Threatening Arrhythmias in Clinically Manifest Cardiac Sarcoidosis With and Without Current Indications for an Implantable Cardioverter Defibrillator." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center, VCU Health in Richmond, Virginia. Dr. Peder Myhre: And I'm Dr. Peder Myhre, Social Media Editor in Circulation from Akershus University Hospital, and University of Oslo, Norway. Dr. Carolyn Lam: Oh, I am so excited about our feature paper today. It is about a condition that may not be as commonly encountered, but this paper can change clinical practice. It's about cardiac sarcoidosis and the indications for an ICD. Listen up. Very important stuff and discussion coming right up. But first, let's grab coffees and discuss the other papers in today's issues. Shall we? Dr. Greg Hundley: Right. So Carolyn, Peder, how about I go first? And so, both of you... we start with a really interesting, very practical study. It's somewhat unclear whether replacing an oral glucose tolerance test with just a hemoglobin A1C measurement for diagnosing diabetes is justified. And so these authors led by Adam Tabák, from University College of London in the United Kingdom, aimed to assess proportion of oral glucose tolerance tests, diagnosed diabetes cases that can be confirmed with hemoglobin A1C measures. And to examine whether individuals with oral glucose tolerance test diagnoses, but non-diagnostic hemoglobin and A1C are at higher risk of macro and microvascular disease. So the study included 5,773 men and women from the population based Whitehall II prospective of cohort study in the United Kingdom. New oral glucose tolerance tests, diabetes cases diagnosed in clinical examinations between the years of 2002 and 2004. And again, in 2007 and 2009 were assessed for hemoglobin A1C confirmation of a value greater than 6.5% in these. And then again, so in those years, and then again, in subsequent clinical examinations in the periods of 2012 to 2013 and 2015 to 2016, now all participants were followed for major cardiovascular events via linkage to electronic health records until the year of 2017. And for incident chronic kidney disease by an estimated glomerular filtration blade of less than 60 mLs per minute per meter squared, until the last clinical examination. Dr. Peder Myhre: Thank you, Greg. That is such an important study with direct clinical implications. And I'm so curious to know what did they find? Dr. Greg Hundley: Right, Peder. Right, Carolyn. Carolyn's in the background, it's like a mind meld with Peder. She's going to keep pounding me with these same questions. Okay. So in this population based cohort study, with five yearly repeated oral glucose tolerance tests and hemoglobin A1C measurements, only 59.3% of the oral glucose tolerance tests diagnosed diabetes cases were confirmed by hemoglobin A1C at the same or a subsequent examination during 4.1 years of follow up. Incident oral glucose tolerance test diagnosed diabetes cases with hemoglobin A1C confirmation, and preexisting diabetes cases had similarly increased risks of cardiovascular disease and chronic kidney disease. While notably unconfirmed oral glucose tolerance test cases had a similar risk as the diabetes free population. Dr. Peder Myhre: Wow. That is really remarkable, Greg. Thank you for that summary. But can you please just give us, from this complicated paper, can you just give us some take-home points for the listeners. Dr. Greg Hundley: Right, Peder. So first, in this study, people with oral glucose tolerance tests diagnosed diabetes without diagnostic hemoglobin A1C have a risk of cardiovascular disease and chronic kidney disease, similar to the diabetes free population. And therefore, replacement of oral glucose tolerance tests with hemoglobin A1C based diagnoses appears justified. Second, there seems to be no need to consider oral glucose tolerance testing when hemoglobin A1C and fasting glucose levels are apparently inconclusive. Fasting glucose tests are needed only in exceptional circumstances where hemoglobin A1C results are felt to be unreliable. And then, finally, these findings lend confidence to widespread use of hemoglobin A1C for diagnosing diabetes in the vast majority of clinical settings. Dr. Peder Myhre: Wow. Greg, thank you so much. This was so helpful. Well, I'm going to move on to the second original research article. And that is from the DAPA-HF trial, that I know Carolyn has been quizzing you throughout the years about. So I'm not going to quiz you, but I'm just going to ask you. Did you know that SGLT-2 inhibitors increase hematocrit and that it has been identified as one of the key mediators of the clinical benefits on this class of drugs. Dr. Greg Hundley: So Peder, they're really interesting. And the second week of this you're popping out with these quizzes. I didn't do this to Carolyn. It was like a couple months. So anyway, but- Dr. Carolyn Lam: Way to go, Peder. Way to go. Dr. Greg Hundley: Yeah. Well, the good news is, I can just say yes. I did know that. Dr. Peder Myhre: That's nice. And in this paper, we're going to learn even more. Because the authors are taking this further by looking into the iron metabolism and assessing iron deficiency in the DAPA-HF trial. So just to remind you, although, you are familiar with it at this point, Greg, and of course, Carolyn, the DAPA-HF trial was large RCT testing efficacy and safety of the SGLT-2 inhibitor compared to placebo in patients with heart failure and a reduced ejection fraction. And in this post talk analysis, the authors examine the prevalence and consequences of iron deficiency and the effect of dapagliflozin on markers of iron metabolism. They also analyze the effect dapagliflozin on outcomes according to iron status at baseline. Dr. Greg Hundley: Oh, wow, Peder. So what did they find? Dr. Peder Myhre: So in total, 44% of patients in DAPA-HF were defined as iron deficient. And that was defined as having less than 100 nanogram per milliliter of ferritin or a key set of less than 20% and a ferritin level between 100 and 299 nanogram per milliliter. So the rate of the primary outcome was higher in patients with iron deficiency compared to those without. That was 16 versus 10 per 100% years. And the effect of dapagliflozin on the primary outcome was consistent in iron deficient compared to iron replace patients with a fever interaction of 4.59. And similar findings were observed for cardiovascular death, heart failure hospitalizations and all-cause mortality. And finally, and very importantly, ferritin, T cell, and hepcidin were reduced with dapagliflozin versus placebo. So the authors conclude that iron deficiency was common in DAPA-HF. And associated with worse outcomes. Dapagliflozin, appeared to increase iron utilization, but improved outcomes, irrespective of iron status at baseline. Dr. Greg Hundley: Very nice, Peder. Wow. Just another important piece of information that we're learning about SGLT-2 inhibition. Well, Peder, my next paper comes from the world of preclinical science and it's from a group of authors led by Dr. Osamu Takeuchi from Kyoto University. Primary pulmonary arterial hypertension, Peder, is often characterized by obliterative pulmonary vascular remodeling, resulting in right heart failure. And although, the pathogenesis of pulmonary arterial hypertension is not fully understood. Inflammatory responses and cytokines have been shown to be associated with pulmonary arterial hypertension, particularly with connective tissue disease. So in this sense, Regnase-1 and RNAs, which regulates mRNAs in coding genes related to immune reactions was investigated in relationship to the pathogenesis of pulmonary hypertension. Dr. Peder Myhre: Wow, Greg. Pulmonary arterial, a hypertension and mRNA degradation of IL-6. So what did they find, Greg? Dr. Greg Hundley: Right, Peder. So these investigators examined the expression levels of Z3H12A in coding Regnase-1, in peripheral blood mononuclear cells from pulmonary hypertension patients classified under various types of pulmonary hypertension, searching for an association between the ZC3H12A expression and the clinical features associated with pulmonary hypertension. They then generated mice lacking Regnase-1 and myeloid cells, including alveolar macrophages and examined right ventricular systolic pressures, and histologic changes in the lung. They found that Regnase-1 maintains lung innate immune homeostasis via the control of IL-6 and PDGF in alveolar macrophages, thereby, suppressing the development of pulmonary arterial hypertension in mice. And furthermore, the decreased expression of Regnase-1 in various types of pulmonary hypertension implied its involvement in pulmonary hypertension pathogenesis. And then, therefore, may serve as a disease biomarker as well as a therapeutic target for pulmonary hypertension. Very, very interesting work from the world of preclinical science. So how about we jump and see what else is in the mail bag? Dr. Peder Myhre: So we have From the Literature by Dr. Tracy Hampton, and this time we get three summaries from preclinical science papers published on their journals. First, there is a summary of a paper suggesting that circadian and pluripotency networks control longevity related genes, and that was published in cell metabolism. There is also a summary from a paper on the varied responses to a high fat diet using mouse models published in high science. And finally, there is a summary related to Brugada syndrome and how gene therapy is a potential future therapy. And that was published in scientific translational medicine. So Greg, what did you have in the mail bag? Dr. Greg Hundley: Sure. Well, Peder, I've got a research letter from Professor Fang entitled “Mitochondrial Stress Induces HRIEIF2A Pathway that's Protective for Cardiomyopathy.” Dr. Peder Myhre: And finally, we have clinical implications of basic research from Dr. Garry and colleagues entitled “Cardiac Xenotransplantation, the Clinical Impact of Science and Discovery.” So let's move on the future discussion, Carolyn. Dr. Carolyn Lam: Absolutely. Thank you for excellent summary, Greg and Peder. Now, let's go the feature discussion on cardiac sarcoidosis. Dr. Greg Hundley: You bet. Dr. Carolyn Lam: Wow. Today's feature discussion is on a rare, but very important topic. And it's that of cardiac sarcoidosis. And you have to listen up because today's paper could actually change practice. So I'm very pleased and grateful to have the authors of this paper. The corresponding author, Dr. Hanna-Kaisa Nordenswan and coauthor, Dr. Jukka Lehtonen both from Helsinki University Hospital. As well as our associate editor, Dr. Mark Link, from UT Southwestern to discuss this very important paper. Hannah-Kaisa if you don't mind, could you start by just telling us about your paper and what you found? Dr. Hanna-Kaisa Nordenswan: Thank you so much for inviting us to the podcast. So cardiac sarcoidosis predisposes to sudden cardiac death. But how well the current guidelines for implantable cardioverter-defibrillators in CS issued by the Heart Rhythm Society in 2014 and the American College of Cardiology, American Heart Association and Heart Rhythm Society, consortium guidelines from 2017, discriminate high from low risk of sudden cardiac death is unknown. And this is what we wanted to examine. So our study is a nationwide study, including 398 patients with cardiac sarcoidosis. All patients had clinical cardiac manifestations and a histological diagnosis of sarcoidosis. The histological diagnosis was myocardial in nearly one half of the population. So patients with and without class 1 to 2A indications for an implantable cardioverting-defibrillator at presentation were identified from this population. The occurrence of fatal or aborted sudden cardiac death and sustained ventricular tachycardias in follow-up were recorded. We also noted ICD indications emerging first on, follow up. Dr. Carolyn Lam: Great. What did you find? Dr. Hanna-Kaisa Nordenswan: So, first of all, we found that by the current ICD guidelines, 85 to 100% of our patients had at least one strong to modest class 1 to 2a indication for an early ICD implementation. And we also found a 10%, five-year cumulative incidence of sudden cardiac death in our population of cardiac sarcoidosis patients. Further, we found that patients without an early indication for an ICD by the Heart Rhythm Society guidelines had nearly 5% cumulative risk of sudden cardiac death at five years. These patients further had a 53% cumulative risk of either developing an indication or suffering from a life-threatening ventricular arrhythmia at five years follow up. Finally, we also found that a diagnosis of cardiac sarcoidosis based on myocardial histology, IE definite CS. So definite cardiac sarcoidosis predicted twice higher combined five-year risk of sudden cardiac death and life-threatening ventricular arrhythmia than diagnosis based on extra cardiac histology, IE probable cardiac sarcoidosis. Dr. Carolyn Lam: Wow. Thank you so much, Hannah-Kaisa and congratulations on such impactful findings. 398 patients and if I read correctly, a cohort spanning 30 years. Jukka, could you tell us a little bit more on how these patients were identified? And I think this is important too, because it speaks to the generalizability of your findings. Dr. Jukka Lehtonen: Exactly. Yeah. So we have a very proactive approach to cardiac sarcoidosis. So basically, if I give you an example, so we screen all patients less than 60 years of age with MRI. And if the MRI shows that there's any signs of myocardial damage, we do endomyocardial biopsy. And then, if we do biopsy, once take 10 samples from the right ventricular septum. If that comes out negative, as it very often comes, then we do a PET study. And if there's an extra cardiac signal, then we do biopsy that side. So usually, it's lymph nodes very often. And that gives us a probable cardiac sarcoidosis. So probable cardiac sarcoidosis is the terminology that's used in Heart Rhythm Society, 2014 guidelines. It has the same prognosis, basically, the definite cardiac sarcoidosis that's based on endomyocardial biopsy. So if the PET shows no signal outside the heart, we usually repeat the biopsy either right or left side, depending where there's most signal. And we can do that up to three times. So we have a very proactive approach. And that explains why we have so many patients. So because you may end up taking 30 biopsy samples and you have one sample that's positive. So that explains why 5.3 million people can have such a huge number of sarcoid patients. We don't think that we are special. We just think that we are very active in biopsy area. And I know that this is something that differs in different places, and the different centers in the US have very different policies, and in Europe as well. So why I think this explains why we have such a large population and why they're all biopsy verified cases. Dr. Carolyn Lam: Thank you so much, Mark. I know that as editors we spotted immediately what a precious, valuable cohort in data we were looking at. Could you frame that for us? Take us behind the scenes a little bit on what you thought when this paper first crossed your desk. Dr. Mark Link: Yeah. This was a paper that caught our interest right away for a number of reasons. One, is the large number of sarcoid patients, nearly 400, that's one of the largest series that's ever been published. And two, is the systematic way in which sarcoid was approached. And what we found fascinating is that once you had a diagnosis of cardiac sarcoid, be it either probable or actual, there was a high risk of having ventricular arrhythmias. And this is something that in the guidelines, it's not so clear, because it's clear if the EF's less than 35%, you should get an ICD. But if your EF's greater than 35% by current guidelines, that's not a class 1 indication. So we thought this paper had the possibility to move guidelines and that perhaps we should think about an ICD and any patient that has diagnosis of cardiac sarcoid. Dr. Carolyn Lam: Wow. That's a brave postulation though. Exactly, as I said at the beginning, I think it may be practice changing. What do you think about that? Jukka and Hannah? Dr. Jukka Lehtonen: I think that's exactly what we have noticed that we have, most of the cardiac sarcoid patients are less than 50 years of age. So I think, the average age is 49 or something. And they're mostly females, so 70% are females. So it's pretty unique cardiac disease, that's more common in females than in males. And I think this population is benefiting tremendously from the ICD therapy, so that's something that we can see. It's not based on randomized data, it's follow up data, but these patients have lots of ICD events, events treated by an ICD. So we think that this is a major problem. Our previous papers have shown that the mortality in sarcoidosis is 90% is ventricle arrhythmia. So this conclusion fits with that previous findings as well. Dr. Carolyn Lam: Wow. Hannah has this impacted your personal clinical practice? I mean, do you now therefore think any patient, especially, if they've got confirmed cardiac sarcoidosis biopsy proven. Are you going to just, no matter what, regardless, anything else be more likely to put an ICD? Dr. Hanna-Kaisa Nordenswan: Yeah. Based on this study, we think that all cardiac sarcoidosis patients presenting with clinical cardiac manifestations and with histologically proven cardiac sarcoidosis should be considered for an ICD implantation. But with patients, with having non-definite cardiac sarcoidosis and without class 1 to 2A indications for an ICD in these patients, probably, the pros and cons of an ICD should be carefully discussed. Well, if an ICD is not implanted, at least repeated risk appraisal is needed regularly during follow up. Dr. Carolyn Lam: That's great comments. Mark, what do you think is going to be needed as future steps to get it to change practice? Or do you think this is it? Because, I mean, this is... the issue is, it's not easy to say let's just do a trial in cardiac sarcoidosis, right? Where are we going to find those patients and so on. What do you think, Mark? Dr. Mark Link: Yeah. That's a very good question. Because this isn't randomized trial data, and the strength of evidence is best with randomized trial data. And will we get a randomized trial in sarcoid? I doubt it. I really doubt it. So we're going to be left with registry data. And so where I would see this going is other registries coming out, showing their data. I think we do need confirmatory data from another large registry or two, and that's going to change practice, but are we there yet? I don't know. I don't know. Based on the lack of randomized trial data. Dr. Carolyn Lam: Thanks. If I could then for the last questions, if I could give it to the authors, what are your plans for next steps, if any. Maybe, Jukka, do you want to start first? Dr. Jukka Lehtonen: Well, I think cardiac sarcoidosis has lots of open questions. It has only open questions. I think the direction we are going is to go to the drug trial. So whether treatment of the inflammation by different agents would provide benefit in terms of arrhythmias and heart failure. So there's an idea that take patients with, for example, that's something that we haven't finalized yet, but take patients with normal ejection fraction, randomized them to cortisone and no cortisone and see how they do. Because we don't really know whether even corticosteroids actually make a huge difference. I think we have more than 200 cardiac sarcoid patients under follow up in our hospital. And I can see that there are patients that have very good prognosis and no events whatsoever over many years or even decade. And then we have other patients that have lots of events, arrhythmias and develop heart failure. So I think we need trials that help us to distinguish those patients and also trials that help us select right medications for each group. Dr. Carolyn Lam: Thank you, Hannah? Dr. Hanna-Kaisa Nordenswan: Based on this particular study, we think that also the next study should preferably be a larger multicenter study that would focus on the prognostic factors in cardiac sarcoidosis. Perhaps, a risk score could be developed by using more detailed information of the presenting manifestations and ventricular function and imaging findings, cardiac magnetic resonance and positron emission tomography. Dr. Mark Link: Yeah. And we at the editorial staff thought this was important enough paper to have an editorial, to comment on its usefulness and way forward in dealing with cardiac sarcoid patients. And this editorial is written by Rick Patton and will accompany the printed issue. Dr. Carolyn Lam: Thanks. And so, you heard it, everyone pick up that editorial, pick up that paper. This is an important topic, and so grateful that it was published with us. Thank you once again to the authors. Thank you once again, Mark, for managing this paper. So lovely. And thank you, audience for joining us today from Greg and I, you've been listening to Circulation on the Run. Don't forget to tune in again next week. Dr. Greg Hundley: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Jonathan Sterne and Associate Editor Shinya Goto as they discuss the article "Association of COVID-19 With Major Arterial and Venous Thrombotic Diseases: A Population-Wide Cohort Study of 48 Million Adults in England and Wales." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor, director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Oh, Greg, we've got a special treat for everyone today. We have a third co-host and he is none other than Peder Myhre from Norway! Really adding to the diversity of our podcast: me from Asia, you from the US, and Peder from Europe. Welcome, Peder. Dr. Peder Myhre: Thank you so much, Carolyn. It's truly an honor to be here and I'm looking forward to being part of this podcast today. Dr. Carolyn Lam: Awesome. Well, here we go. Looks like we have a feature paper, Greg? Dr. Greg Hundley: Absolutely, Carolyn. Peder, welcome. So, listeners, our feature today will involve COVID-19 and its association with arterial and venous thrombotic diseases. But before we get to that, we're going to all grab a cup of coffee from all over the world and get into some of the other articles in the issue. Peder, Carolyn, how about I go first? My first study involves a prospective cohort of 94,000 individuals from the UK Biobank, who had device-measured physical activity from 2013 to 2015 and were free from myocardial infarction and heart failure. Now, Peder and Carolyn, the study was performed because although objectively measured physical activity has been found associated with acute cardiovascular outcomes, it has not been found associated with heart failure and, of course, a syndrome that's been expanding worldwide. As such this study led by Carlos Celis-Morales from the University of Glasgow aimed to investigate the dose response relationship between device-measured physical activity and heart failure by intensity of the physical activity. Now physical activity was measured with a wrist-worn accelerometer and time spent on light, moderate, and vigorous intensity physical activity was extracted. Incidental heart failure was ascertained from linked hospital and death records. Dr. Peder Myhre: Wow, Greg. That sounds amazing. Tell us, what did they find? Dr. Greg Hundley: You bet, Peder! These investigators found that, compared with participants who undertook no moderate to vigorous intensity physical activity, those who performed 150 to 300 minutes per week of moderate intensity physical activity or 75 to 150 minutes per week of vigorous intensity physical activity were at lower risk of heart failure. Now, interestingly, the association between vigorous intensity physical activity and heart failure was a reverse J-shaped curve with a potentially lower risk reduction above 150 minutes per week. And so, the take-home message for this first paper is that device-measured physical activity, especially moderate intensity physical activity, was associated with a lower risk of heart failure. Probably current vigorous intensity physical activity recommendations should be encouraged, but not necessarily increased. In contrast, increasing moderate intensity physical activity may be beneficial, even among those meeting current recommendations. Dr. Peder Myhre: Wow, Greg. That was a great summary. And the second original research article today is about high density lipoproteins. As you know, raising HDL cholesterol levels to prevent cardiovascular disease remains a hot topic. HDL plays a key role in reverse cholesterol transport and may be cardioprotective and reduce infarct size in the setting of myocardial injury. Lecithin cholesterol acyl transferase, LCAT, is the rate limiting enzyme in the reverse cholesterol transport and a recombinant human LCAT called MEDI6012 has previously been shown to increase HDL cholesterol. So in this study from the corresponding author, Marc Bonaca from University of Colorado School of Medicine, the investigators in the real team is 63B multicenter placebo control trial investigated whether randomized patients to, MEDI6012 or placebo would reduce the infarct size as measured by cardiac MRI, 10 to 12 weeks after the STEMI. Dr. Greg Hundley: Very interesting, Peder. So, MRI assessments of LV mass after PCI. So, what did they find? Dr. Peder Myhre: So, Greg, the authors successfully enrolled 593 patients with a median age of 62 years and 78% males. And the median time from symptom onset to randomization was 146 minutes and only 13 minutes from hospitalization to randomization. And the index MI was anterior in 70% and 65% had TIMI Flow grade 0-1. And then to the main results at 12 weeks, the infarct size did not defer between the treatment group. So that was a 9.7% infarct size for MEDI6012 versus 10.5% for placebo with a P value of 0.79. And there was also no difference in noncalcified black volume. So the authors conclude that enhanced reverse cholesterol transport with recombinant human LCAT did not reduce infarct size or late regression of noncalcified coronary REPL at 12 weeks. Okay, Greg. So tell me about the 3rd paper you have today? Dr. Greg Hundley: Peder, what a great description on that previous paper, beautiful job there. So Peder, this next article pertains to cardio toxicity related to the administration of anthracycline-based chemotherapy. And an example would be Doxorubicin. And this occurs in patients often with certain types of cancer. As you know, Doxorubicin is still utilized for the treatment of leukemia, lymphoma, soft tissue sarcoma and in the setting of adjuvant breast cancer treatment. And so to this end, the authors, led by Lorrie Kirshenbaum from St. Boniface Hospital abstract research, wanted to assess cytokine mediated inflammation in myocellular injury, as a result of some of the inflammation that's induced by the administration of Doxorubicin. So as a little bit of background, cytokines, such as TNF alpha, have been implicated in cardiac dysfunction and toxicity associated with Doxorubicin. Now, while TNF alpha can elicit different cellular responses, including survival or death, the mechanisms underlying these divergent outcomes in the heart really somewhat remain cryptic. The E3 ubiquitin ligase, TRAF2, provides a critical signaling platform for K63 length poly ubiquitin nation of rip K1, crucial for NF-kB activation by TNF alpha and survival. Whether alterations in TNF alpha, TRAF2, NF-kB activation signaling underlie the cardiotoxic effects of Doxorubicin, remains poorly understood. So herein, these authors investigated TRAF2 signaling in the pathogenesis of Doxorubicin cardio toxicity. Dr. Peder Myhre: Oh wow, Greg. So we're talking mitochondrial dysfunction in Doxorubicin cardiomyopathy. So please tell me, what did they find and what were the clinical implications? Dr. Greg Hundley: Very nice. Peder, you remind me of Carolyn, asking me the clinical implications. Okay, so first, in mouse models and in vitro measures in rats, mouse and human pluripotent stem cell derived cardiomyocytes, these investigators monitored TNF alpha levels, LDH, cardiac ultra structure and function, mitochondrial biogenics, as you just suggested, and cardiac cell viability. They found that a novel signaling axis exists that functionally connects the cardiotoxic effects of Doxorubicin to proteasomal degradation of TRAF2. Disruption of the critical TRAF2 survival pathway by Doxorubicin, sensitizes cardiomyocytes to TNF alpha and BNIP3 mediated necrotic cell death. Perhaps, interventions that stabilize TRAF2, so here's the clinical implication, may prove beneficial in mitigating the cardiotoxic effects in cancer patients undergoing anthracycline-based chemotherapy. Dr. Carolyn Lam: So Greg, he may sound like me, but this is me going what an amazing summary and especially in something that is your specialty cardio-oncology, that's amazing. Thank you. Peder, I assume you've got one more paper? Dr. Peder Myhre: So Greg, now I'm going to sound like you and say that we are going to stay within the world of preclinical science. So genome-wide association studies have identified many genetic loci that are robustly associated with coronary artery disease. However, the underlying biological mechanisms are still unknown for most of these loci, hindering the progress to medical translation. And there is evidence to suggest that the genetic influence of coronary artery disease sociability may partly act through vascular smooth muscle cells. So corresponding author, Shu Ye from University of Leicester, performed genotyping, RNA sequencing and cell behavior assays on the large bank of vascular smooth muscle cells with an N of almost 1500. And through these extensive analysis, they saw to identify genes whose expression was influenced by coronary artery disease associated variants. Dr. Greg Hundley: Very nice, Peder. So, more about cardiac gene expression. So, what did they find? Dr. Peder Myhre: Approximately 60% of the known coronary artery disease associated variants show statistically significant effects in vascular smooth muscle cells and the study identified 84 candidate causal genes whose expression quantitative trait, loci signals in vascular smooth muscle cells, significantly co-localized with reported coronary artery disease association signals, of which 38 of them are potentially druggable, so, that was the clinical implications. The authors conclude that a large percentage of coronary artery disease loci can modulate genes, gene expression in vascular smooth muscle cells and influence these cell behavior. Several candidate causal genes identified are likely to be druggable and thus represent potential therapeutic targets. And Greg, accompanying this paper is a beautiful editorial by doctors O'Donnell and Bradner entitled "Bridging the Gap to Translating Genome-Wide Discoveries into Therapies to Prevent and Treat Atherosclerotic Cardiovascular Disease." Dr. Greg Hundley: Very nicely done Peder, very nicely done. Well, as usual, we have some other items, we call it in the mail bag because we receive these wonderful research letters and also research correspondence. So I'll go first. First, Dr. Al-Khatib has a research letter entitled, "Duration of Anticoagulation Interruption before Invasive Procedures and Outcomes in Patients with Atrial Fibrillation Insights from the Aristotle Trial." And also there's a nice ECG analysis by Dr. Tsai entitled, "A Peculiar Wide-Complex Tachycardia During Flecainide Treatment." Dr. Peder Myhre: Nice, Greg, and there's also an exchange on letters to the editors and the response from Professors Zhao and Ding, and again, a response from Professor Zhang regarding the prior letter by Jin et al. pertaining to the previously published article "Micro RNA, 210 Controls, Mitochondrial Metabolism and Protects Heart Function in Myocardial Infarction." Dr. Greg Hundley: Beautifully done, Peder. Oh, wow. Welcome to this team. We're so excited to have you. And now Carolyn, I think we're going to jump over to that feature discussion and learn a little bit more about COVID-19 and arterial and venous thrombotic disease. Dr. Carolyn Lam: You bet! Let's go, Greg and Peder. Now we all know that infection with COVID 19 induces a pro-thrombotic state, but the long term effects of COVID-19 on the incidence of vascular disease, both arterial and venous, remain unclear. That is until today's feature paper. We're so grateful to have corresponding author Dr. Jonathan Stern, from the University of Bristol, as well as our associate editor, Dr. Shinya Goto from Tokai University School of Medicine to join us and discuss this very important paper today. Jonathan, could you start us off on telling us why it's so important to look at this? Haven't we always known that infections, COVID or not, are associated with pro-thrombotic state? So what's so different about what you did and what you found this time? Dr. Jonathan Stern: So, yes, I think we already knew that serious infections, in particular infections leading to hospitalization, can result in thrombotic events, either arterial or venous. And it was also clear from January, February, March 2020, that COVID led to very serious infection and therefore was likely to lead to vascular events. The questions that we set out to address, beyond simply establishing that COVID does indeed do this, was to quantify by how much COVID multiplies the rate at which these thrombotic events occurred, to do that separately for different events, such as myocardial infarction, stroke, venous thromboembolism, pulmonary embolism. And then to importantly, because we analyzed a very large dataset, which we might want to talk about, to try to separate out the amount by which the rating events was multiplied over time and in important subgroups, for example, in hospital people who were hospitalized for their COVID, compared with people who weren't hospitalized for their COVID, by age and sex, and by other demographic characteristics. Dr. Carolyn Lam: I love that, you see, that really set out the novel information this added with, may I add, very important clinical implications, which we'll get to them. You've already teed me up to talk about this 48 million adults that you managed to look at. Oh my goodness! Tell us, how in the world did you do that? Dr. Jonathan Stern: Well, I think the first thing to say is that it's my absolute privilege to talk about this paper on behalf of a really incredible team that put the work together. And a lot of that work, or that work started with really unlocking the power of NHS data because of the COVID pandemic. So in the UK, we have a national health service, free at the point of delivery to everybody. The NHS assembled electronic health records, and there's been a long and proud history of research based on electronic health records in the UK. But for the first time, because of the pandemic, a combined data resource for the whole of England, so that's a population of about 58 million people, was established and that linked primary care data - data from family doctors, data on secondary care hospital admissions, data on COVID testing and subsequently, although it's not the subject of this paper, data on vaccination. So those data were all linked and put into one place within what's called a trusted research environment with very strict controls on what can be output from the environment in order to protect patient privacy. And that was really done during 2020. And then the analyses for this paper took place during 2021, and it was an enormous amount of work by a large and absolutely fantastic team of people across multiple UK universities and national health service institutions. Dr. Carolyn Lam: Wow. Bravo! We talk about big data, we talk about using it. I trained in the NHS system. Who knew that this could come out to reveal such important results? So thank you for that as a background, but now, tell us what you found please? Dr. Jonathan Stern: So we found that rates of these conditions, they were primarily acute lymph infarction and ischemic stroke, which we grouped together with other conditions as arterial thrombotic events, and then deep vein thrombosis and pulmonary embolism, which we grouped together with other conditions as venous events. And we found that rates were substantially multiplied immediately after a diagnosis of COVID by up to 748 times, that the amount by which rates were multiplied diminished with time since COVID, but importantly that even six months to a year after that first diagnosis of COVID, rates of venous events were still about double in people who'd had COVID, compared to people who had COVID. And we found, it seemed quite clear that the persistence of the elevated risk was longer for venous events than for arterial events. Dr. Carolyn Lam: Just really fascinating results and Shinya, could I ask, what are your thoughts on this? And as you were managing this paper, the implications? Dr. Shinya Goto: First of all, thank you very much, Jonathan, for choosing saturation for your great paper. I'm handling quite a lot of papers, but your paper was very attractive. As Carolyn mentioned, it's huge data! 48 million, it's surprising, and also you also pick up booster rate of arterial embolism event for years, and you have also shown adjusted rate is initially increased quite a lot and then decreased gradually. And even after two months, three months still, there is a persisted higher risk. And as you mentioned, for the venous thrombo embolism, it's persisted for more than year to year. It's surprising. COVID-19's a different disease. Perhaps COVID-19 infection cuts to the vascular endarterial cell, perhaps, your research raised a lot of research questions, like endarterial damage induced by COVID-19 in the past 6 months; I would say more than half a year to one year. So that mechanistical insight is very important. And you raise a lot of any clinical questions. Dr. Jonathan Stern: Well, thank you very much for your kind words and you are right, I think we are left with questions about maybe in three areas. Firstly, for how long is there an elevation in risk? I should probably say, for those who haven't read the paper, that these results relate to events that occurred in England and Wales during 2020. And so that is in an era before vaccination and when we were dealing with the original variant, and to some extent, the alpha variant. So we are still waiting to see what the implications were over longer periods, and we will be doing that, we will be extending follow up. In fact, we are at the moment extending those results. I think, secondly, we are left with questions about the mechanisms, which you articulated, and thirdly, there's the question about, well, what are the implications for clinical management of patients with COVID-19? And in particular, for patients who've had severe COVID-19, for example, severe enough to be hospitalized for it? Dr. Shinya Goto: Yeah, you have also showed a very important point that even known hospitalization for COVID-19, the risk of thrombosis becomes high. So it's very surprising. And even non-hospitalized patients have a higher risk of thrombosis. That is probably the huge difference between other virus infections and COVID-19. Dr. Jonathan Stern: Yes. The good news, if you weren't hospitalized for your COVID, is that the elevation in risk declines more rapidly for people with less severe COVID who weren't hospitalized than for people with more severe COVID who were hospitalized. But nonetheless, as you say, particularly in the first week, two weeks, three weeks after COVID, there is a clear elevation in the risk of both arterial and venous events, even if you were not hospitalized for your COVID. We should probably also bear in mind that these results for 2020, when there were severe constraints for some of the time on health service resources. So you probably had to be pretty sick to get hospitalized at that time. Dr. Carolyn Lam: That was a very important caveat that you just highlighted. So thank you for contextualizing those findings for us, Jonathan, but then I kind of wish all podcast guests were like you, and you already asked a question, I was going to ask you. Which is, okay, so what's the clinical implication? Should we all be taking some low dose NOAC or aspirin? Whether you're hospitalized or not? Or if you were in 2020? Because, jokes aside, I know that you found some very important risk factors? Or these events which had clinical implications? Could you expand on it? Dr. Jonathan Stern: So maybe I'd start by saying that we didn't find that these patterns varied dramatically either by sex or by age. And in fact, when we were planning the analyses, I was convinced that we would see dramatic differences in these hazard ratios by age. And, broadly speaking, the facts on a multiplicative scale, the amount by which your rate is multiplied, looked similar across age groups and by sex. On the other hand, we did see the amount by rates of arterial and venous events were multiplied, appeared greater in people of Asian ethnicity or Black ethnicity than in people of White ethnicity. A counterintuitive finding was that the amount by which your rate was multiplied is lower, if you've had a prior event than if you hadn't. Those are the sorts of extents to which we can say something about how your own characteristics predict the consequences once you've had COVID. In terms of management, obviously the pandemic has been tumultuous for medicine and for medical research and things have moved on greatly since the pre-vaccination era, 2020 and early 2021, to which these analyses relate. So the first thing to say is, don't get hospitalized with COVID, and the best way to not be hospitalized with COVID, is to be fully vaccinated for COVID. And that's a message that I think the whole of the medical profession has communicated loudly and clearly for a long time now. So the second thing is, well, okay, what about if, nonetheless, you got COVID, particularly severe COVID, and we discussed this in the team extensively, and I particularly want to mention the senior clinical author, Dr. Will Whiteley from the University of Edinburgh in this regard, and I think the main message here is that risk factor management, cardiovascular risk factor management is always important, but it's probably particularly important in people who've had severe COVID to review risk factor management and make sure that existing guidelines in terms of cholesterol lowering, blood pressure lowering and so on, are being adhered to. We don't... So the most important thing is adherence to existing cardiovascular risk management guidelines. I think we don't have evidence that specific additional interventions are indicated in people who've had COVID, and COVID now in the era of Omicron and widespread vaccination is not the same as COVID during 2020. Dr. Shinya Goto: Jonathan, you have raised a very important issue. I strongly recommend all audiences to read this paper. We have to know persistent or higher risk of myocardial infarction, ischemic stroke, may be controlled more regularly controlled. Don't fear the COVID-19 infection to visiting the healthcare professional. In my country, some of the population stopped coming to the healthcare professional because they fear so much about infection from the hospital or clinic. But it's very important to keep that regular control like static and blood pressure control. Maybe we don't have that data about aspiring or not, but strong message your paper gave is that risk factor control after COVID-19 is very important. Dr. Jonathan Stern: I completely agree. Dr. Carolyn Lam: And I would add to that, remember the days when people were stopping their ACE inhibitors and so on for those fear? So what a great message and thank you for giving us a little bit of a peek into the future of what you're planning next with more follow up, in a population that is vaccinated from a different strain perhaps. And I think this still encourages hopefully more trials and research into this whole area of how we should be managing these patients. Well, thank you so much both of you for discussing this very, very current relevant, important paper. Thank you for publishing it in circulation with us. And to the audience, thank you for joining us today. From Greg and I, you've been listening to Circulation on the Run, and don't forget to tune in again next week. Speaker 6: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join authors Svati Shah and Senthil Selvaraj as well as Guest Editor and Editorialist Manuel Mayr as they discuss the article "Metabolomic Profiling of the Effects of Dapagliflozin in Heart Failure With Reduced Ejection Fraction: DEFINE-HF" and the editorial "SGLT2 Inhibitors in Heart Failure: Targeted Metabolomics and Energetic Metabolism." Dr. Carolyn Lam: Welcome to Circulation On Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts, I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health Richmond, Virginia. Dr. Carolyn Lam: In today's feature paper, we will be talking about the metabolomic profiling of the effects of dapagliflozin in heart failure, and this is from the DEFINE-HF trial. It's just such a cool paper with a lot of insights you have to hear from the authors. But, before we get there, let's talk about some of the other papers in today's issue. Shall we, Greg? Dr. Greg Hundley: You bet, Carolyn. Well, how about if I go first? Dr. Carolyn Lam: Please. Dr. Greg Hundley: Thank you, Carolyn. My first paper comes to us from Professor Paulus Kirchhof from the Universitäres Herzzentrum in Hamburg. Carolyn, in the randomized EAST-AFNET 4 study, so the early treatment of atrial fibrillation for stroke prevention, these trial investigators demonstrated that systematic initiation of early rhythm control reduced adverse cardiovascular outcomes in patients with recently diagnosed atrial fibrillation and stroke risk factors. However, the effectiveness and safety of early rhythm control in patients with multiple cardiovascular comorbidities is not known. Carolyn, in this study, it was a prespecified sub-analysis of the EAST-AFNET 4 trial and it compared the effectiveness and safety of early rhythm control with usual care stratified into patients with high CHA2DS2-VASc scores of greater than or equal to 4. Dr. Carolyn Lam: Nice. Okay. Important question, what did they find? Dr. Greg Hundley: Right, Carolyn. Quite a bit of data in this study, so let's walk through it carefully. First, in regards to the study population, the EAST-AFNET 4 randomized 1093 patients with CHA2DS2-VASc scores of greater than or equal to 4, these were predominantly women, 61% female, and then also 1,696 patients with CHA2DS2-VASc of less than four, and these were predominantly men, so only 37% women. Now let's get to the date. Early rhythm control reduced the composite primary efficacy outcome of cardiovascular death, stroke, or hospitalization for worsening heart failure or for acute coronary syndrome in patients with high CHA2DS2-VASc scores of greater than 4, but not in patients with CHA2DS2-VASc scores of less than 4. Second, now Carolyn, the primary safety outcome, so death, stroke, or serious adverse events of rhythm control therapy, was not different between study groups in patients with high CHA2DS2-VASc scores of greater than 4, but occurred more often in patients with low CHA2DS2-VASc scores randomized to early rhythm control. Now Carolyn, life threatening events or death were not different between the groups. When female sex was ignored for the creation of high and lower groups, the interaction P was not significant for the primary efficacy outcome, but remained significant for the primary safety outcome. Dr. Carolyn Lam: Oh, you are right. A lot of interesting data here. What's a take home message? Dr. Greg Hundley: Right, Carolyn. So the take home message is the following. Patients with recently diagnosed atrial fibrillation and multiple cardiovascular comorbidities should be considered to have priority access to early rhythm control to reduce cardiovascular outcomes, and a specific trial of early rhythm control in these patients is really needed as a next step. Dr. Carolyn Lam: Oh, thank you, Greg. The next paper focuses on arrhythmogenic right ventricular cardiomyopathy, which we know is characterized by a high propensity to life threatening arrhythmias and progressive loss of heart muscle. More than 40% of reported genetic variants linked to arrhythmogenic right ventricular cardiomyopathy, or ARVC, reside in a gene called plakophilin-2, or PKP2. In today's paper, Dr. Delmar and Lundby from NYU Grossman School of Medicine and University of Copenhagen, respectively, and their colleagues, described a comprehensive characterization of the ARVC molecular landscape using a multidisciplinary approach including human samples from ARVC patients with PKP2 mutations and left ventricular ejection fraction above 45%, as well as PKP2-deficient murine and human induced pluripotent stem cell-derived cardiomyocytes. They studied all of these with comprehensive proteomics and functional analysis. Dr. Greg Hundley: Wow, Carolyn, another great study in circulation combining both preclinical murine models as well as data from human subjects. So, what did they find? Dr. Carolyn Lam: Precisely, Greg. Here's what they found. Loss of nuclear envelope integrity and subsequent DNA damage is a key substrate in the molecular pathology of AR VC. The authors further showed transcriptional down regulation of proteins of the electron transcript chain as an early event in the molecular pathophysiology of the disease prior to an ejection fraction falling below 45%. This associates with increased oxidant production, with the clinical message being, therefore, that the authors propose therapies that limit oxidant formation may be a possible intervention to restrict DNA damage in ARVC. Dr. Greg Hundley: Very nice, Carolyn. Okay, our next paper comes from Dr. Donald Lloyd-Jones from Northwestern University, the Feinberg School of Medicine. Carolyn, you can tell the change in inflection of my voice because it's time for another Carolyn's quiz. Carolyn, open-ended question. Can you remind us of life's essential eight? Dr. Carolyn Lam: Oh boy, Greg. It's like asking me to name the dwarfs. I know I'm going to forget one, but here you go. Diet, exercise, cholesterol, weight, smoking, sugar must be there, diabetes, blood pressure. You see, I got seven. What's the eighth? Dr. Greg Hundley: Yeah. Remember seven dwarfs, Sleepy. Dr. Carolyn Lam: Sleep. Dr. Greg Hundley: Very good. Great job, Carolyn. Dr. Carolyn Lam: Thank you. Dr. Greg Hundley: Recently, the American Heart Association recently published an updated algorithm for quantifying cardiovascular health, the Life's Essential 8 score. In this study, the investigative team quantified US levels of cardiovascular health using the new score. They included non-pregnant, non-institutionalized individuals aged 2 through 79 years who were free of cardiovascular disease from the National Health and Nutrition Examination Surveys that were conducted between 2013 and 2018. Now, for all participants, they calculated the overall cardiovascular health score, and it ranged from 0, which is really low, to 100, which is the highest, as well as the score for each component. And Carolyn, yes, you are very close. Remember the eight? Diet, physical activity, nicotine exposure, sleep duration, body mass index, blood lipids, blood glucose, and blood pressure, and they used published American Heart Association definitions of these. The cardiovascular health scores were assessed across strata of age, sex, race, ethnicity, family income, and depression. Dr. Carolyn Lam: Okay, Greg. What did they find? Dr. Greg Hundley: Right, Carolyn. There were 23,400 plus participants, representing 201,728,000 adults and 74 million children. The overall mean cardiovascular health score was 64.7 among adults using all eight metrics, and it was 65.5 for the three metrics available of diet, physical activity, and BMI among the children and adolescents that were aged 2 through 19 years. Now, for the adults there were significant differences in mean cardiovascular health scores by sex, age, and racial ethnic group. Mean scores were lowest for diet, physical activity, and the BMI metrics. There were large differences in mean scores across demographic groups for diet, nicotine exposure, blood glucose, and blood pressure. In children, diet scores were low, 40.6, and were progressively lower in higher age groups. Large differences were also noted in mean physical activity and BMI by sociodemographic group. Carolyn, this study basically identifies wide ranges of scores across multiple domains of the essential eight, and thus, this new Life's Essential 8 score helps identify large group and individual differences in cardiovascular health. Additionally, overall, cardiovascular health in the US population remains well below optimal levels, and there are both broad and targeted opportunities to monitor, preserve, and improve cardiovascular health across the life course in both individuals, as well as the population at large. Dr. Carolyn Lam: Wow. Thanks, Greg. Truly really interesting. Everyone's going to have to pick up that paper and all the other papers in this issue, because there's also an In Depth paper by Dr. Whelton on “Harmonization of the ACC/AHA and ESC/ESH Blood Pressure Hypertension Guidelines, Comparisons, Reflections, and Recommendations. There's a Research Letter by Dr. Munshi on the accurate classification of cardiomyopathy etiology by chromatin accessibility. Dr. Greg Hundley: Carolyn, I have got to report an exchange of letters from Professor Sun and Weng regarding the article, “Legumain Is an Endogenous Modulator of Integrin αvβ3 Triggering Vascular Degeneration, Dissection, and Rupture.” And then Carolyn, lastly, there's a Perspective piece from Professor Vidal-Petiot entitled, “Thresholds for Hypertension Definition, Treatment Initiation, and Treatment Targets: Recent Guidelines at a Glance.” Well, Carolyn, how about we get on to that feature discussion? Dr. Carolyn Lam: Yes, let's go Greg. Wow, we have a star stud cast for today's feature discussion, and on a star studied topic, if I may. It's on the SGLT2 inhibitors, this time in the DEFINE-HF study and really going into the mechanism of action of SGLT2 inhibitors. Now, that's one question I personally get all the time. How do these things work? Today's paper brings us one step closer, for sure, in the understanding. I'm so grateful to have the first author, Dr. Senthil Selvaraj from University of Pennsylvania, as well as the corresponding author of the paper, Dr. Svati Shah, associate editor, as well as the corresponding author from Duke Molecular Physiology Institute. We also have Dr. Manuel Mayr who was both the guest editor and editorialist for this paper, and Dr. Mayr is from Kings College London, British Heart Foundation Center. Welcome, everyone. Senthil, get us started here. The DEFINE-HF study, just a quick summary, what that was about and then what you did, what you found. Dr. Senthil Selvaraj: Absolutely. Good morning, everyone, or maybe good evening for your time, Carolyn, but we were very excited about this study and the ability to do targeted metabolomic profiling in DEFINE. This audience is well familiar with the fact that SGLT2 inhibitors are foundational therapy in heart failure reduced ejection fraction, and the interesting thing is, despite a lot of literature, we still don't know why. Whether it relates to change in inflammation or endothelial function, but given the mechanism of action, metabolism is sort of at its core. So in this study we sought to identify metabolic pathways that were associated with dapagliflozin treatment using this targeted metabolomics platform in which we assayed 63 metabolites, acylcarnitine, which are markers of fatty acid oxidation, several amino acids, and ketone-related metabolites. To do this, we studied 234 participants from DEFINE, which is a 12-week placebo-controlled trial of dapagliflozin in this population, and we perform principal components analysis for dimensionality reduction techniques. In this study, briefly we found that, first, our principal components analysis yielded 13 different factors that accounted for the substantial proportion in the variation of the data, and that two in particular, ketone-related metabolites and short acylcarnitines in factor 6, as well as medium-chain acylcarnitines in factor 7 were differentially associated with dapagliflozin treatment. Specifically, there were increases in several ketone-related metabolites and short acylcarnitines, as well as several medium-chain acylcarnitines, really speaking to, potentially, changes in fatty acid as well as ketone biology with dapagliflozin treatment. The second aim of our study was to look at changes in metabolites and changes in endpoint studying DEFINE, which included NT-proBNP as well as KCCQ scores. We found that dicarboxylate long-chain acylcarnitines and aromatic amino acids really related to worsening heart failure endpoints there. So, a lot to impact, a lot that we found, and appreciative about the opportunity. Dr. Carolyn Lam: Oh, wow. Thank you so much for that amazing summary. Svati, I've heard you speak so many times on metabolomics on our calls, but this is really so important. First, I think the question is, congratulations for thinking ahead of time to collect the samples and to do all of this. Congratulations on that. Could I ask if you went in with any specific hypothesis or were you surprised by these findings, Svati? Dr. Svati Shah: Yeah, Carolyn, thank you so much. It was such a pleasure to work with Senthil on this and I really want to highlight what an incredible early career investigator he is. He's really going to set the metabolism world on fire. I also wanted to say thank you to the PI of the clinical trial, the parent clinical trial DEFINE-HF Mikhail Kosiborod, who did the really hard work of collecting the samples along with the clinical trial itself. To me, what's really cool is to be able to take a clinical trial like this with really important clinical outcomes well adjudicated and to be able to dig into the mechanism at a metabolic level of what might be going on with SGLT2 inhibitors. Going into this, Carolyn, we suspected that ketone-related biology was at play. There have been studies in other populations, non-HFrEF populations, that have shown that SGLT2 inhibitors have what appears to be beneficial impacts on ketone biology and induced ketosis. So, going into this, we suspected that this ketone pathway was going to come up. I think what's exciting is, not only did we find that the ketone pathway was differential modified by dapagliflozin, but that it wasn't at the level of severe ketosis that we would be concerned about. And then secondly, we found pathways of fatty acid oxidation. Some related to the effects of the medication and some related to changes in functional outcome. So it really enhanced beyond what we already knew about ketone biology, expanded our understanding of potential mechanisms of SGLT2 inhibitors, and expanded this into the HFrEF space, Carolyn. Dr. Carolyn Lam: Oh, that's so nice. I'm bursting with questions, but I really, really have to ask Dr. Manuel Mayr, first, could you put these findings into context for us and tell us what they mean clinically? Dr. Manuel Mayr: Yeah, Carolyn. First of all, I want to join you in congratulating the authors to this important study. As Svati mentioned, previous studies have reported effects of SGLT2 inhibitors on ketone bodies, but the present study really adds to the literature because it uses the state of the art metabolomic techniques. It uses a technique called mass spectrometry, but they also have a rating of, I think, in total, 63 metabolites in over 200 patients. Mass spectrometry is becoming increasingly important for cardiovascular precision medicine because we can use it in clinical trials to provide an unbiased assessment of metabolites and proteins. So it's a very versatile technology. I think this study really adds to the rapidly growing literature that SGLT2 inhibition is a principle of unloading the failing heart from metabolic stress. Dr. Carolyn Lam: Wow, I really like that and your editorial is just beautiful. I love that you say, "After the serendipitous findings of improved heart failure outcomes with SGLT2 inhibitors, mechanisms were postulated, but studies, such as the one we're discussing, are needed to really uncover what's the real thing." Now, I know this may sound really oversimplified and so on, but I'd really love for Senthil or Svati to just bear with me as I ask, what are you going to say to people who go, "Okay, then we should just be downing ketones," Or, "We should be Working on the fatty acid parts of it," Or taking conclusions like that. What would you say to something like that? Dr. Senthil Selvaraj: I'm happy to go first. It's a really wonderful question and I do think that this study raises the question of whether we should be exogenously increasing ketone levels to provide some sort of benefit. I would say the jury's still out there. I think it's a hot topic right now. But there are also differences between how we raise key tone levels, whether you do that endogenously in the body, or whether you give something like a ketone supplement, so exogenous ketone supplementation. And I think that there are completely different physiologies there. So more to come. I think there are a lot of studies in this space. The ketogenic diet is something that I'm often asked as well, whether that might provide benefit to heart failure. There are a lot of ways that I can, but one thing that we need to be mindful of is the fact that it will reduce glycogen stores as well, which may impact exercise capacity. So, we need more data. I would say the other thing that we found in our studies, while they were increased in ketone levels and markers of fatty acid oxidation with dapagliflozin treatment, we aren't necessarily sure that those mediate the benefits of SGLT2 inhibitors. DEFINE has important clinically relevant endpoints, but it is not an event-based trial. And so we don't know and we can't link the changes in metabolites with changes in outcomes quite yet. Dr. Svati Shah: Carolyn, just to add to the wonderful response that Senthil just gave, I think we do have to be careful. We don't know whether these are direct effects of SGLT2 inhibitors or whether these are related to the caloric loss that we know happens with these medications. I think it's important to point out that we're looking in the blood, we don't actually know what's happening at the tissue level, so we do have to be a little bit careful. We have made inferences that this is reporting on substrate fuel selection in the heart, but we also suspect that skeletal muscle and other organs are heavily involved in some of the pathways we're seeing. So I just wanted to make those important caveat to the epidemiologic work that we do. Dr. Carolyn Lam: And those are so important, so thank you Senthil and Svati. Manuel, I'd love to invite your thoughts because you did sort of point out some of these points in your editorial. Could you maybe discuss a bit of those and raise any questions, perhaps? Dr. Manuel Mayr: Yes. I think Svati and Senthil have nicely mentioned already that these measurements are performed in plasma. So the changes in plasma could be due to, for example, increased production in the liver due to decreased consumption in other tissues. So I guess the next step would be, and I would be really interested on what the authors want to pursue, is to provide direct evidence for the energetic hypothesis, that really the heart is consuming these keto bodies and what type of measurements could be performed to provide direct evidence in humans for these metabolic hypothesis. Dr. Senthil Selvaraj: That's a really great question, Manuel. There was a really nice study that was published about a year or two ago in Science in which the authors did coronary sinus sampling. So really to get arterial venous gradients, measure substances in the arterial system as well as the coronary sinus venous system and get extraction. I think that that study would be very interesting to understand. You take patients on SGLT2 inhibitors, those who are not, and to understand what is the heart chewing on. Obviously more invasive than some other approaches, but other studies that I think would be really interesting in those space would be flux studies and stable isotope studies. Again, as Svati really nicely mentioned, these are systemic physiology snapshots whenever we do less localized techniques like that, but they're still very important because heart failure is a systemic process. Dr. Carolyn Lam: Anything to add, Svati? Dr. Svati Shah: No, I think you said it beautifully. I'll just say on the sort of epidemiologic side, to be able to link this to harder outcomes, DEFINE-HF wasn't really designed to be able to do that. So as we expand our understanding of SGLT2 inhibitors, understand different populations, and to link these pathways to more objective outcomes, I think, will be really useful, also. Dr. Carolyn Lam: Indeed. Manual, in your editorial, you actually discuss some of your own work, which may be the ones that Senthil is actually talking about. What is your view? Dr. Manuel Mayr: Well, I think I'm very excited that beyond fatty acid metabolism and glucose metabolism, ketones have extracted increasing attention. Ketone body metabolism, I think, has long been underappreciated. We still need to understand to what extent it really acts as a fuel and that it can help to overcome the energy deficit that creates heart failure. I think, as mentioned by Svati and Senthil, we need more studies in this area, and of course other trials are ongoing where they're going to measure, for example, the phosphocreatine to ATP ratio by using phosphor-NMR spectroscopy. So we get direct evidence whether there really is an energetic improvement upon SGLT2 inhibition. I think this will be studies to look forward to and to add to the growing literature that metabolism is important as a therapeutic target for heart failure. Dr. Carolyn Lam: Oh, such exciting times. You mentioned the EMPA-VISION trial in your editorial. I think I'm trying to tell everybody, you have to pick up the paper and the editorial. You're going to learn so much. This is so cool. Thank you so, so much all of you for being on this podcast, for sharing your thoughts. I'm sure everyone has learned a lot and enjoyed it just as I have. On behalf of Greg and I, thank you for being here, thank you for joining us today, and don't forget to tune in again next week. Thank you. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Keith Channon as he discusses the article "Risk of Myocarditis After Sequential Doses of COVID-19 Vaccine and SARS-CoV-2 Infection by Age and Sex." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts, I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke-National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor, director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Oh, Greg, today's feature paper, something that's really been discussed a lot in the press and in lay public as well, the risk of myocarditis following sequential doses of the COVID-19 vaccine and SARS-CoV-2 infection by age and sex. Everyone's going to want to tune into that one. But before we get there, shall we go through some of the key papers in today's issue? Dr. Greg Hundley: You bet, Carolyn. How about if I go first? Dr. Carolyn Lam: Please. Dr. Greg Hundley: So Carolyn, this first manuscript involves the world of machine learning and ECG interpretation. And as you know, novel targeted treatments increase the need for prompt hypertrophic cardiomyopathy detection; however, it's low prevalence, 0.5%, and resemblance to common diseases really present challenges. So Carolyn, these authors, led by Dr. Rahul Deo from Brigham and Women's Hospital, sought to develop machine learning models to detect hypertrophic cardiomyopathy and differentiate it from other cardiac conditions using EKGs and echocardiograms with a robust generalizability across multiple cohorts. So Carolyn, what did they do? They used single-institution hypertrophic cardiomyopathy EKG models that were then trained and validated on data from three academic medical centers in the United States and Japan using a federated learning approach, which enables training on distributed data without data sharing. Models were validated on held out test sets for each institution and from a fourth academic medical center and were further evaluated for discrimination of hypertrophic cardiomyopathy from aortic stenosis, long-standing hypertension, and cardiac amyloidosis. And then finally, automated detection was compared to manual interpretation by three cardiologists on a data set with a realistic hypertrophic cardiomyopathy prevalence. Dr. Carolyn Lam: Wow, incredible. So what were the results? Dr. Greg Hundley: Right, Carolyn. So the authors identified 74,476 EKGs for 56,129 patients and 8,392 echocardiograms for 6,825 patients across the four academic medical centers. Now, while ECG models trained on data from each institution displayed excellent discrimination of hypertrophic cardiomyopathy on internal test data, the generalizability was limited, most notably for a model trained in Japan and then subsequently tested in the United States. Now, however, when trained in a federated manner, discrimination of hypertrophic cardiomyopathy was excellent across all institutions, including for phenotypic subgroups. The models further discriminated hypertrophic cardiomyopathy from hypertension, aortic stenosis, and cardiac amyloid. Analysis of ECG and echocardiography paired data from 11,823 patients from an external institution indicated a higher sensitivity of automated HCM detection at a given positive predictive value compared with cardiologists. So Carolyn, in conclusion, federated learning improved the generalizability of models that use EKGs and echocardiograms to detect and differentiate hypertrophic cardiomyopathy from other causes of left ventricular hypertrophy compared to training within a single institution. It will be really interesting to see the future applicability of these methods. Dr. Carolyn Lam: Oh, I'm such a fan of this work. Awesome. Thank you, Greg. My paper, it's a preclinical paper that uncovers a novel mechanism through which GATA4 mutations can lead to heart disease. Dr. Greg Hundley: All right, Carolyn, no quiz this time, I'm just coming right out. I'm reversing the question on the teacher. Tell me, what is GATA4? Dr. Carolyn Lam: I'm glad you asked, Greg. GATA4 is a zinc finger-containing DNA binding transcription factor essential for normal cardiac development and homeostasis in mice and humans, and mutations in this gene have been reported in human heart defects. Now, in today's paper, authors led by Dr. Srivastava from Gladstone Institutes in San Francisco, California, showed that GATA4 regulated cell-type-specific splicing through direct interaction with RNA and the spliceosome in human-induced pluripotent stem cell-derived cardiac progenitors. An unbiased search for GATA4 interacting proteins in these human iPS cells revealed interaction with many members of the spliceosome complex. GATA4 also bound to pre-messenger RNAs in a sequence-specific manner that resulted in generation of alternatively spliced isoforms in human iPS cells. Many of these GATA4-dependent isoforms had distinct functional properties illustrating the importance of the splicing regulation to cardiac function. Dr. Greg Hundley: Wow, Carolyn, another really interesting study from the world of preclinical science. So what's the take home message here? Dr. Carolyn Lam: So these results essentially uncover a previously unrecognized function for GATA4 in regulating alternative splicing through direct RNA interaction. Several genes that have splicing regulated by GATA4 have functional consequences and many are associated with dilated cardiomyopathy, thus suggesting a novel role for GATA4 in achieving the necessary cardiac proteome in normal and stress-responsive conditions. Dr. Greg Hundley: Very nice, Carolyn, wow. Well, my next paper comes to us from back in the world of clinical science and it's from Professor Bertrand Cariou from L'institut du Thorax in Inserm UMR1087. So Carolyn, only a few genes causally related to plasma LDL-C levels have been identified so far, and only one, ANGPTL3, has been causally related to combined hypocholesterolemia. In this study, the authors aim to elucidate the genetic origin of an unexplained combined hypocholesterolemia inherited in four generations of a French family and used next generation sequencing and identified a novel dominant rare variant in the LIPC gene encoding for hepatic lipase, which co-segregates with the phenotype. They characterize the impact of this LIPC-E97G variant on circulating lipid and lipoprotein levels in family members using nuclear magnetic resonance based lipoprotein profiling and lipids. Dr. Carolyn Lam: Wow, what an interesting approach to study patients and families with hypocholesterolemia for once instead of hyper. Interesting. So what did they find? Dr. Greg Hundley: Right, Carolyn. So the investigative team found that this unique LIPC-E97G variant specifically increases the phospholipase activity of hepatic lipase without affecting triglyceride lipase activity. And second, the hypocholesterolemic phenotype related to LIPC-E97G variant is due to an increased clearance of cholesterol within triglyceride-rich lipoprotein remnants predominantly by extrahepatic tissues. Dr. Carolyn Lam: Wow, so what are the implications? Dr. Greg Hundley: Right, Carolyn. So the novel gain of function variant in LIPC potentially represents the second cause of familial combined hypocholesterolemia after loss of function variants in ANGPTL3. And second, this study highlights an unexpected and critical role of the phospholipase activity of hepatic lipase encoded by LIPC in LDL-C metabolism and identifies it as a potential novel drug target. And then finally, Carolyn, additional data, I think, are warranted to clarify the impact of LIPC-E97G-related combined hypocholesterolemia on atherosclerosis and atherosclerotic cardiovascular disease due to the occurrence of documented coronary stenosis and evolutive carotid atherosclerosis in index cases. Dr. Carolyn Lam: Oh, very, very interesting. Thanks, Greg. Well, let's wrap up with the discussion of what else is in today's issue. There's an In Depth paper by Dr. Hadley on protecting cardiovascular health from wildfire smoke. There's also a Research Letter by Dr. Mevorach on myocarditis after BNT162b2 COVID-19 third booster vaccine in Israel. Dr. Greg Hundley: Right, Carolyn. And then I've got an exchange of letters from Professors Condello and Doenst regarding the article Cytokine Hemoadsorption During Cardiac Surgery Versus Standard Surgical Care for Infective Endocarditis from the REMOVE study: Results From a Multicenter Randomized Controlled Trial. Well, how about we get on to that feature discussion and learn a little bit more about COVID-19 vaccine and SARS-CoV-2 infection. Dr. Carolyn Lam: Let's go, Greg, thanks. Dr. Greg Hundley: Listeners, welcome to this September 6th feature discussion. And with us today, very interesting topic pertaining to vaccination for SARS-CoV-2 virus prevention. And we have with us Dr. Keith Channon from Oxford, England, to discuss this very interesting paper. Well, Keith, welcome. I wanted to start by asking you, can you describe for us a little the background information that went into the preparation of your study, and what was the hypothesis that you wanted to address? Dr. Keith Channon: Thanks, Greg, for the opportunity to join you in this interesting conversation today. A group of cardiologists in the UK based at the University of Oxford, and principally at the University of Edinburgh, have been interested in the question as to whether COVID infection and/or COVID vaccination might lead to a higher incidence of myocarditis. And this is a topic that has been the subject of previous publications in the field. And the provocation for us undertaking this study is that those previous studies have tended to be relatively small, and they've also not been able to necessarily test the details, time association, between myocarditis occurring in relation to sequential doses of vaccination. And that's important because, of course, we're now all receiving sequential doses of booster vaccines, and also those vaccines are often delivered, different vaccine types to different people in different countries. So we wanted to test whether there does appear to be a significant association between the occurrence of myocarditis and both COVID infection and the sequential different COVID vaccinations. Dr. Greg Hundley: Very nice. So Keith, can you describe for us, what study population did you enroll for this initiative? And then also, what was your study design? Dr. Keith Channon: Thank you. So, one of the really exciting things about this type of study and probably what makes it unique is that in countries with healthcare system, like that in the UK, which is the National Health Service, and universities, such as the University of Oxford and the University of Edinburgh, where there are very strong academic links between researchers and the National Health Service, we've been able to leverage an enormous data set, which is almost 43 million people in the UK who underwent vaccination against COVID-19. And rather than having to follow up 43 million people as part of a research study, we were able to take advantage of National Health Service centralized coded hospital records, number one. Number two, we took advantage of the UK's national database on COVID vaccination. And number three, we were able to look at hospital outcomes and also COVID testing. So we were able to put together those three data sets for us to understand who developed COVID infection, who received COVID vaccination, and if so, which vaccine and when, and who then was admitted to hospital with a coded diagnosis of myocarditis. And in 43 million people, even though myocarditis is a very uncommon outcome, there were sufficient cases in that very large population to draw statistically meaningful conclusions. I think that the UK is probably one of the few countries where this type of research can be done. And academic organizations, like our universities, the National Health Service, and also cardiovascular research funders, such as the British Heart Foundation, have put in a lot of resource and effort into giving us those capabilities to answer questions like this, and it's turned out to be a very powerful capability. Dr. Greg Hundley: Very nice. And so Keith, can you describe for us your study results? Dr. Keith Channon: So the study looked at a large 43 million people approximately over a period of time during the early to mid-phase of the COVID pandemic and looked at the likelihood that people would be diagnosed with myocarditis following either vaccination or COVID test positive. And we compared that likelihood with the likelihood of myocarditis occurring outside of those periods; because, of course, myocarditis occurs reasonably commonly in the general population. So this is another powerful aspect of the study design. It has a curated approach to look at the incidence of myocarditis in the 28 days after either vaccination or COVID infection, and it corrects, or it controls for that relative to the incidence of myocarditis outside of those sampling periods. And what we found simply is that there is indeed, as previous studies have shown, a small but significant association between receiving a COVID-19 vaccine and being diagnosed with myocarditis in the following 28 days. However, in the population as a whole, the risk of myocarditis after vaccination is substantially lower than the risk of developing myocarditis after COVID infection, and I think that's an important finding. When we looked at subgroups, which is interesting, we found that the highest risk of developing myocarditis was in men less than age 40, so younger men, and that was one finding. And also, there did seem to be some differences in the risk of myocarditis occurring after different sequential vaccine doses. Dr. Greg Hundley: Keith, just a quick clarification point, what vaccines did you examine? Dr. Keith Channon: So in the UK, the three vaccines that have been largely used of the AstraZeneca Oxford viral vaccine, ChAdOx1, which was of course introduced very early in the UK, along with the Pfizer mRNA vaccine, and then laterally, Moderna vaccine, which of course in the UK was brought in rather later. And I think that's interesting because, as we can go on and discuss, there do appear to be some possible differences between those vaccines in terms of the likelihood of being diagnosed with myocarditis afterwards. But of course, even our experiment in 43 million people is not a perfect design because it's an observational study, and the periods in the pandemic when people were receiving principally the first two vaccines, which were by far the most numerous, was a different period in the natural history of the pandemic than when we started administering Moderna. So it is important to recognize that it was not a prospectively controlled randomized trial of different vaccines; it was an observational study of pretty much a whole country and how it responded to the implementation of those different vaccines, which were all given to different people at different times of the pandemic. And of course, different times of the pandemic means that many different people will have already had a COVID infection and then gone on to have a booster or third vaccination. So, if you like, the immunological landscape in which these different vaccines were given in this very large population will have been different. Dr. Greg Hundley: Right. So I understand there are differences in timing, great point, but did you see any differences in the occurrence of myocarditis relative to either of the mRNA vaccines versus the adenovirus vaccine? Dr. Keith Channon: Yeah, we did. What we found is that, interestingly, there did appear to be a higher likelihood of being diagnosed with myocarditis in the 28 days after the mRNA-1273 vaccine, Moderna vaccine, and that was particularly, as I've already said, in men younger than the age of 40 years. I should say again, of course, that vaccine was given to the smallest number of people in the UK and it also tended to be rolled out later, so it was the second or third dose of the vaccine where that signal was most seen. But again, the second and third dose was by definition typically the booster vaccine later on in the pandemic. But that's what we found. We did find these interesting differences. The incidence of myocarditis was increased after all of the vaccine doses compared with the period when people had not received a vaccine, but this was a very modest increase for most of the vaccines; but for the mRNA vaccines, particularly Moderna, it seemed to be more strikingly increased in the 28 days after the second or third dose of the vaccine. So I guess the message from that result is that there do seem to be these intriguing differences, both in the response to different COVID vaccines, either viral or mRNA or indeed even different types of mRNA vaccine, and possibly after the different dose of vaccines. In other words, after second or third sequential doses. Dr. Greg Hundley: And Keith, you mentioned a few minutes ago that you also had an opportunity to examine situations where maybe a patient had a vaccine and then subsequently contracted COVID, or vice versa, maybe they had had COVID and then later on had a vaccine, did you find any differences in the incidence of myocarditis in those situations as opposed to, perhaps, patients that really never had a documented episode of a COVID infection and then always had received the two vaccines and the booster dose? Dr. Keith Channon: Yeah, that's a harder question and is less powerfully addressed by our study, even though we were able to temporally control for that. Previous COVID infection did not preclude the risk of myocarditis after subsequent vaccine doses, but it wasn't a big enough signal to be able to give much detail over the relative risk between... Because if you think of the permutations of COVID infection plus or minus three vaccines, there's a lot of different sequential steps there, but having had COVID first doesn't prevent this small but significant signal; having a vaccine before you then get COVID infection does reduce your risk of myocarditis along with pretty much all other COVID complications. So I think that's a really important public health message here and indeed the overarching finding of our study, which you could argue is the least exciting one but perhaps the most important, which is that you have a higher likelihood of suffering with myocarditis after COVID infection compared with after a COVID vaccination. And if you have COVID vaccination, in general, your risk of myocarditis is lower, obviously your risk of COVID infection is lower, and your risk of getting myocarditis after that COVID infection, should you still get one is also lower. So I think these are very intriguing, interesting findings that might make us think about mechanism and vaccine policy, but ultimately there are very strong endorsement of getting vaccinated to prevent the consequences of COVID-19. Dr. Greg Hundley: Excellent point. And then, Keith, just quickly, next study that maybe your group is considering in this space with this large database? Dr. Keith Channon: Yes. Well, I think there are two aspects to the study. Our group, which, as I've said, focuses mainly on large epidemiological data sets, having established this infrastructure in the UK led by universities like Oxford and Edinburgh and funded by the British Heart Foundation and others, means that we now have this infrastructure. So the surveillance and the data collection and the analysis is ongoing and we'll be able to add more cases and more power and more data, and there will be other studies that we can look at. Second, I think there are some really quite interesting mechanistic studies that could be done based on these provocative findings to try to understand which different types of vaccines and, indeed, the immune responses which those vaccines generate. How are they linked to myocarditis and, indeed, to other cardiac and even other organ complications from COVID-19? And there are ongoing studies in the UK and elsewhere in the world that are very much focused on looking at the organ-specific consequences of COVID infection in patients who've been vaccinated or not. For example, using detailed cardiac MRI to look at the heart and look for subclinical myocarditis and to correlate any evidence of subclinical myocarditis with the immune signature, both the antibody and the cellular immune response, in the blood from those patients. So I think what we're going to see here are enormous epidemiological studies with n=43 million, and we're also going to see more mechanistic experimental medicine immunology studies to try and tease out mechanism, and I think to understand two things. One is how to protect ourselves best against COVID-19, and what are the best vaccines and how best to use them. And second, if we can learn something about the mechanisms of myocarditis along the way, that's a really useful bonus that's come out of this pandemic. Dr. Greg Hundley: Very nice. Well, listeners, we want to thank Dr. Keith Channon for bringing us this very interesting article from Great Britain highlighting that, overall, the risk of myocarditis is greater following SARS-CoV-2 infection as opposed to a COVID-19 vaccination, and even really remains modest following sequential doses, including the booster dose of some of the mRNA vaccines. Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. This program is a copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit AHAjournals.org.
This week, please join author Rod Stables and Associate Editor Nick Mills as they discuss the article "Routine Pressure Wire Assessment Versus Conventional Angiography in the Management of Patients With Coronary Artery Disease: The RIPCORD 2 Trial." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast, summary and backstage pass through the journal and its editors. We're your co-hosts! I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature... Very interesting. There is a lot of information about using fractional flow reserve during contrast coronary angiography. But how does that compare to just reviewing the angiograms when managing patients with coronary artery disease? Well, we are going to hear some results from the RIPCORD 2 trial, and they may surprise you a little bit. But, before we get to that interesting feature discussion with authors and editors, how about we grab a cup of coffee and dive into some of the other articles in the issue? Dr. Carolyn Lam: Yeah, let's do that, Greg. Do you have a paper to share first? Dr. Greg Hundley: Oh, thanks Carolyn. Sure. So Carolyn, as we know, Apolipoprotein B or apoB, provides an integrated measure of atherogenic risk. But whether apoB levels and apoB lowering hold incremental predictive information on residual risk after acute coronary syndromes, beyond that provided by low density, lipoprotein cholesterol, or LDLC, that's uncertain. So Carolyn this study emanates from the Odyssey Outcomes trial, which compared the Proprotein Convertase Subtilisin/Kexin Type 9 inhibitor, Evolocumab with placebo in 18,924 patients with recent ACS and elevated atherogenic lipoproteins despite optimized statin therapy. Now the primary outcome was major adverse cardiovascular events. So MACE was coronary heart disease, death, nonfatal myocardial infarction, fatal non-fatal ischemic stroke, and hospitalization for unstable angina. And associations between baseline ApoB or ApoB at four months and MACE were assessed in adjusted Cox proportional hazards and propensity score matched models over median of 2.8 years. Dr. Carolyn Lam: Oh, right. So what were the results, Greg? Dr. Greg Hundley: Right, Carolyn so impatience with recent ACS and elevated atherogenic lipoproteins, MACE increased across baseline ApoB strata, and now evolocumab reduced MACE across all strata of baseline ApoB, with larger absolute reductions in patients with higher baseline levels. Lower achieved ApoB was associated with lower risk of MACE, even after accounting for achieved LDLC or Non-HDLC indicating that ApoB provides incremental information. And therefore, Carolyn, if it is modified achievement of an ApoB level less than or equal to 35 milligrams per deciliter may reduce lipoprotein attributable residual risk after ACS. Isn't that interesting? Dr. Carolyn Lam: Yes. Very nice, Greg. Thank you. This next paper is a pre-specified analysis of the EMPEROR-Preserved trial, looking at patients with and without diabetes. Dr. Greg Hundley: So remind us, Carolyn, what was the EMPEROR-Preserved trial and what did it show? Dr. Carolyn Lam: Well, in EMPEROR-Preserved Empagliflozin, the SGLT2 inhibitor reduced risk of the composite of cardiovascular death or heart failure hospitalization, as well as first and recurrent heart failure hospitalizations and slowed renal function decline in patients with heart failure and an ejection fraction greater than 40%. So the current paper sought to determine if effects were consistent in patients with, and without diabetes, of the almost 6,000 patients enrolled, 49% had diabetes. The risk of adverse outcomes, first of all, was higher in patients with diabetes. Now the treatment effect of Empagliflozin was however, similar in that Empagliflozin reduced the rate of the primary outcome and total heart failure hospitalization, irrespective of diabetes status. The effect of Empagliflozen falls into attenuate GFR decline, however, was also present in patients with, and without diabetes, although more pronounced in patients with diabetes. Now across all these three endpoints, the effect of Empagliflozen did not differ in patients with prediabetes or normal glycemia. And importantly, there was no increased risk of hypoglycemic events in either subgroup compared with placebo. So a very nice paper there. And that was from Dr. Gerasimos Filippatos from Athens University Hospital Attikon and colleagues. Dr. Greg Hundley: Wow, Carolyn, just really interesting information coming out of the world of SGLT2 innovation. Well, Carolyn, my next paper comes to us from the world of preclinical science and it's from Dr. Kunhua Song from the University of Colorado Anschutz Medical campus. So Carolyn, abnormalities of calcium homeostasis are closely associated with cardiac arrhythmias and heart failure and conditions that cause death of millions of people every year. Now, Carolyn Triadin physically interacts with the Ryanodine receptor 2 and plays an important role in releasing calcium from the sarcoplasmic reticulum to increase the free intracellular calcium concentration in cardiomyocytes. Now alternative splicing of a single Triadin gene produces multiple Triadin isoforms, the predominant cardiac Triadin isoform mouse Mt1 or human Trisk 32 is encoded by Triadin exons from one to eight. In humans, mutations in the Triadin gene that lead to a reduction in Trisk 32 levels in the heart cause cardiac dysfunction, cardiac arrhythmias and sudden death. Decreased levels of Trisk 32, in the heart, are also common in patients with heart failure. However, mechanisms that regulate alternative splicing of the Triadin gene to maintain levels of cardiac Triadin protein in the heart, remains somewhat elusive. Dr. Carolyn Lam: Wow. I am always learning from these cool papers. Thanks Greg. So what were the results? Dr. Greg Hundley: So Carolyn, the investigators found several things. First, the cardio MyoSite specific long non-encoding RNA or link RNA Triadin AS is essential for maintenance of cardiac function, exercise capacity and normal lifespan and Triadin AS knockout mice were found predisposed to cardiac arrhythmias in response to catecholamine challenge. And finally Carolyn, Triadin AS controls, levels, of cardiac Triadin isoforms, by regulating the splicing of the Triadin gene. Dr. Carolyn Lam: Oh, wow. All right. So could you bring it home for us, Greg? What are the clinical take home messages? Dr. Greg Hundley: Right, Carolyn. So cardiac explants from human heart failure patients as well as patients with cardiac arrhythmias, demonstrate reduced expression of Triadin AS and Triadin. And then next the mechanism of the Triadin AS and Triandin AS mediated alternative splicing of the Triadin gene to specifically control levels of cardiac isoforms of Triadin in the heart, provides a potential strategy for the treatment of cardiac arrhythmias and heart failure. Dr. Carolyn Lam: Wow. Thank you, Greg. Well, let's talk about what else is in today's issue. There's a Research Letter by Dr. Agarwal on Chlorthalidone for resistant hypertension and advanced chronic kidney disease. Dr. Greg Hundley: And Carolyn, I've got a perspective piece by Professor Cowie pertaining to atrial fibrillation entitled, “I'm Sorry, Mrs. Jones, but We Cannot Make You Feel Better Today.” Well, Carolyn, how about we get onto that feature discussion and review the utility of fractional flow reserve measurements, in patients undergoing contrast coronary angiography. Dr. Carolyn Lam: Great, let's go. Dr. Greg Hundley: Welcome listeners to this August 30th feature discussion. And we have with us this afternoon, Dr. Rod Staples from Liverpool and our own associate editor, Dr. Nick Mills from Edinburgh, Scotland. And gentlemen, welcome, Rod we'll start with you. Can you describe for us the background information that went into the preparation of your study and what was the hypothesis that you wanted to address? Dr. Rod Staples: Okay, well thanks very much for hosting today. I'm very grateful to be working circulation on this. I'm working with my co-lead investigator Professor Nick Harrison from Southampton, who's been doing an enormous amount of work on coronary physiology. He actually did the original RIPCORD study, what I suppose we'd now call RIPCORD 1, but it was called RIPCORD in the early days, an observational study that showed that systematic use of fractional flow reserve at the time of diagnostic angiography. Assessing the functional significance measured in each of the major coronary vessels, appeared in an observational study to have a dramatic effect on the subsequent management plans allocated to patients. And we decided to test this in a prospective randomized trial. Dr. Greg Hundley: Very nice. And so the exact hypothesis that you were going to test was what? Dr. Rod Staples: At the time of coronary angiography, a strategy of systematic measurement of fractional flow reserve in each and every coronary vessel, large enough to be considered for revascularization, would improve outcomes compared to a strategy based on angiographic assessments alone. Dr. Greg Hundley: Very nice. And so you mentioned a randomized trial. Can you describe further your study design and then which study population did you include? Dr. Rod Staples: Well, this is a classic multicenter randomized trial performed in the UK. We actually recruited in 17 different UK centers. We asked them to assess patients who were scheduled for invasive, currently angiography for participation against some very minimal inclusion and exclusion criteria, trying to keep the trial generalizable with good external validity. I think one important point to note is that we did allow the inclusion of both patients being assessed with elective angiography for stable symptoms, but in the end half of the population were recruited in the context of a stabilized acute coronary syndrome, a Non-ST-elevation event a day or so down the line. Dr. Greg Hundley: And just a quick breakdown, how many men, how many women? Dr. Rod Staples: Well, it's in that respect, the population is very, very typical for this type of cardiovascular trial. A 70, 30 split an age in the midsixties, a diabetic population in the high teens. So a very typical population we've seen in all this kind of trial environment. Dr. Greg Hundley: Very nice. And so about 1100 patients. And then what were your study results? Dr. Rod Staples: Well, I think there was a very good adherence to the study protocol, very, very few crossovers. And also we were pleased to see that our investigators stayed true to the protocol in that the median number of epicardial vessels assessed by FFR in that randomized arm was four. So there was a good assessment by FFR. The trial was interesting in another respect, in that we assessed an economic outcome based on all NHS hospital costs over the following year and a patient reported outcome based on quality of life using the WHOQOL, and interestingly we found no significant differences either in total subsequent hospital costs from randomization for a year, or indeed in patient reported quality of life by WHOQOL or Angina symptoms by the Canadian Cardiovascular Society classification. Dr. Greg Hundley: Very nice. And then, what about clinical events? Did you examine those as well? Dr. Rod Staples: We did. And again, just a little caveat here, the trial is again interesting in that, what is often in the UK these days called a lean efficient methodology. Whereby, rather than individually contacting individual trial participants or scouring medical records, we interrogated the central national NHS digital repository of all hospital admissions. And we examined electronically a download of every hospitalization event for every patient using algorithms based on diagnostic and procedural codes to define events. And again, we found a very credible representative rate exactly at incidents and events we would've predicted, but again, no difference between the randomized groups. Dr. Greg Hundley: Very nice, well listeners, now we're going to turn to our own Associate Editor, Dr. Nick Mills. And Nick, again, you see many papers come across your desk. What attracted you to this particular manuscript? And it's very interesting study results. Dr. Nick Mills: Thanks, Greg. Firstly, it addresses an important clinical question. Going beyond that, what appealed to me was it was investigator initiated. It was managed by independent trials unit. It recruited a target, it reported the registered outcomes and it was thoughtfully interpreted. And the fact that it didn't prove the hypothesis was irrelevant because it addresses a really important clinical question. And I think it requires some context, and that is that from the previous randomized trials The FAME series, we have been chastised as interventional cardiologists for not using FFR for relatively low use of FFR clinical practice. It's always around one in 20 patients in most series, given the evidence that FFR guided intervention improves outcomes. But actually what FFR is good at is discouraging you from stenting patients with stable Coronary Disease. And so, I think a pragmatic trial that addresses that, the fundamental question, should we be doing more FFR more broadly in both acute and stable disease to guide revascularization with a definitive message that we shouldn't, it doesn't improve quality of life. It doesn't alter costs. Clinical outcomes are similar, but there are more complications associated with routine pressure wire use, gives us a very clear steer for the future. So this is a really important trial addressing a fairly fundamental clinical question. Dr. Greg Hundley: Very interesting. Well, Rod, we're going to turn back to you with Nick's comments and how we're really seeing an evolution in thought processes regarding both diagnostic angiography, and then also the use of functional testing. What do you see is the next study, really in this sphere of research that would be performed? Dr. Rod Staples: Well, I agree with Nick in a way that this raises important philosophical points about the use of intelligence, selective employment of tests or interventions, and that perhaps we need to reflect this in the way we conduct our future studies. I think we're all aware that fractional flow reserve and other measures of functional significance are tremendously valuable in certain clinical settings. And that value's been proven in randomized trials, but in PRECORD 2, for example, if a patient randomized to angiography only was an acute coronary syndrome patient, who had inverted their T waves in their anterior leads, had an associated troponin rise, an echocardiogram had shown some Hypokinesia in the anterior territory. Then I think the potential value of PCI in the LAD does not necessarily require FFR confirmation, and hence that patient will have an equivalent outcome in the angiography group. Similarly, high quality pre-angiography preparation in the elective population with functional testing, stress testing, other forms of imaging mean that we can reserve the use of invasive fractional flow reserve, tight indices to more selective use. Dr. Greg Hundley: And Nick, turning to you, what do you think is the next research study that could be informative in this space? Dr. Nick Mills: I think our whole philosophy by how to manage stable coronary disease is changing. In part because of some other landmark trials that the Ischemia trial and some of the key secondary analyses of the Ischemia trial that tells the Pathoma burden, low attenuation plaque, other aspects of chronic disease are vitally important in predicting major events in the future. And that leaves us with the role for FFR or CT FFR, primarily to manage symptoms. And I think we're getting increasingly good evaluating patients before they get to the Cathflow, optimizing their medical treatment. And so for me, the trial that we really need to help us, is a CT FFR trial to understand the role of Ischemia testing plus anatomical testing and how they dovetail in guiding treatment decisions before they get to the cath lab. I think we need to move this before the lab, always going to be a role for intelligent FFR testing in selected patients once we get to it. But I think that the question probably needs to be addressed before they get to the cath lab. Dr. Greg Hundley: Very nice. Well listeners, we want to thank, Dr. Rod Staples from Liverpool and Dr. Nick Mills from Edinburgh, Scotland for bringing us this very interesting study, highlighting that a strategy of systematic FFR assessment, when compared to angiography alone, did not result in a significant reduction in cost or improvement in quality of life. Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week On the Run. This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Kory Lavine and Associate Editor Thomas Eschenhagen as they discuss the article "Donor Macrophages Modulate Rejection After Heart Transplantation." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: I'm Dr. Greg Hundley, associate editor and director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature, we are going to the world of preclinical science and we are going to learn about a very important new finding pertaining to heart transplant rejection, and macrophages may modulate this, but before we get to that feature, how about we grab a cup of coffee and go through some of the other articles in the issue? Dr. Carolyn Lam: I got mine. Would you like to go first, Greg? Dr. Greg Hundley: You bet, Carolyn. Well, my first study comes to us from Dr. Michael Pencino from Duke University. Carolyn, this study was performed to understand the predictive utility of a previously derived polygenic risk score for long-term risk of coronary heart disease and its additive value beyond traditional risk factors and how that might be able to inform prevention strategies. To accomplish this, data from adults aged 20 to 59 free of cardiovascular health disease from the Framingham Offspring Study and the Atherosclerosis Risk in Communities, or ARIC Study, were analyzed. Now, since the polygenic risk score was derived from people of predominantly European ancestry, individuals who self-reported white race were those that were included. Dr. Carolyn Lam: Oh, interesting, so what did they find, Greg? Dr. Greg Hundley: Right, Carolyn. Somewhat surprisingly, they found that, among 9,757 participants, both the traditional risk factor score and the polygenic risk score where significantly associated with incident cardiovascular heart disease in young, early midlife, and late midlife. Now, the delta C index, when the polygenic risk score was added to the traditional risk factor, score was 0.03, 0.02, and 0.002 in the young, the early midlife, and the late-midlife participants, respectively. Carolyn, despite a statistically significant association between the polygenic risk score and the 30-year risk of cardiovascular heart disease, the C index improved only marginally with the addition of the polygenic risk score to the traditional risk factor model among young adults and did not improve among midlife adults and, thus, Carolyn, the polygenic risk score, an immutable factor, has limited clinical utility for long-term cardiovascular heart disease prediction when added to a traditional risk factor model. Dr. Carolyn Lam: I really like that, Greg, because I think it also tells us that the traditional risk factors, which we can do something about, are still very important. Isn't that great? Well, the next paper is about POTS. Remember what that is? Should I give you a quiz? All right. It's okay. POTS, or Postural Orthostatic Tachycardia Syndrome, is a disorder of orthostatic intolerance that primarily affects females of childbearing age. While the underlying pathophysiology of POTS is not fully understood, it has been suggested that autoimmunity may play a role. Now, the aim of this study was to compare concentrations of autoantibodies to cardiovascular G protein-coupled receptors between 116 POTS patients and 81 healthy controls, and they were from Calgary, Canada, and Malmo, Sweden. Dr. Greg Hundley: Carolyn, really interesting, so what did they find here? Dr. Carolyn Lam: The investigators, led by Dr. Raj from University of Calgary in Canada, found that commercially available autoantibody concentrations to G protein-coupled receptors were not increased or altered in POTS patients relative to healthy controls as assessed using ELISA. Now, while this study suggests that these G protein-coupled receptor autoantibody concentrations alone cannot explain the pathophysiology of POTS, autoantibody activity and signals not picked up by ELISA should still be explored as these results may provide more insights into the pathophysiology of POTS. Dr. Greg Hundley: Very nice, Carolyn. Well, my next study comes to us from the world of pulmonary arterial hypertension. Carolyn, clinical worsening is commonly used as an endpoint in pulmonary arterial hypertension trials. These authors, led by Dr. Steeve Provencher from the Institut Universitaire de Cardiologie Pneumologie de Quebec, aimed to assess the trial-level surrogacy of clinical worsening for mortality in pulmonary artery hypertension trials and whether the various clinical worsening components were similar in terms of frequency of occurrence, treatment-related relative risk reduction and importance to patients. Dr. Carolyn Lam: Okay, so what did they find? Dr. Greg Hundley: Right, Carolyn, so they searched MEDLINE, Embase and the Cochrane Library for trials evaluating the effects of pulmonary arterial hypertension on clinical worsening and, among 35 independent cohorts, so 9,450 patients, the effects of pulmonary arterial hypertension-specific therapies on clinical worsening modestly correlated with mortality. Additionally, study-level clinical worsening was not found to be a surrogate for mortality in pulmonary arterial-hypertension trials. Moreover, components of clinical worsening largely vary in frequency, response to therapy and importance to patients and, thus, are not necessarily interchangeable. Dr. Carolyn Lam: Thank you, Greg. Can I tell you about some other papers in today's issue? There's a Research Letter from Dr. Cosentino on cardiorenal outcomes with ertugliflozin by baseline metformin use, and this is a post hoc analysis of the VERTIS CV trial. Dr. Greg Hundley: Oh, very good, Carolyn. Well, I've got an exchange of letters from Professors Boriani and Steinberg regarding the article “Driving Restrictions and Early Arrhythmias in Patients Receiving a Secondary Prevention Implantable Cardioverter-Defibrillator, the DREAM-ICD-II Study.” There's also an ECG Challenge from Professor Gao entitled “Syncope in a 3-Year-Old Child During the Perioperative Period. What is the diagnosis? What Signs Point Toward Impending Life-threatening Event?” Then, finally, there's a nice, On My Mind piece from Professor Greenland entitled “Insurance Payers Should Cover Selective Coronary Artery Calcium Testing in Intermediate Risk Primary Prevention Patients.” Well, Carolyn, how about we get on to that feature discussion and dive into the world of rejection after heart transplantation? Dr. Carolyn Lam: Yay. Here we go. Dr. Greg Hundley: Welcome, listeners, to this feature discussion on August 23rd. We have a very interesting article today to discuss with our author and associate editor pertaining to preclinical science and cardiac transplant rejection. Our author today is Dr. Kory Lavine from Washington University in St. Louis and our associate editor today is Dr. Thomas Eschenhagen from Hamburg, Germany. Welcome gentlemen. Kory, we'll start with you. Can you describe for us some of the background information pertaining to the construct of your study and what was the hypothesis that you wanted to address? Dr. Kory Lavine: Well, thank you for having me. Our study focused on heart transplant rejection, which remains a major clinical challenge that limits both the survival of heart transplant recipients as well as availability of donor hearts. Current clinical practice really focuses on suppressing the immune system in a global way, and that is somewhat effective, but carries important risks that include infection and life-threatening malignancies. Many studies have appropriately focused on immune cells that infiltrate the transplanted heart that come from the recipient to search for new ways to suppress the immune system safely. What we've understood and learned over the past several years is that the donor heart has its own immune system and its own immune cells, and the majority of those immune cells that come with the donor heart are macrophages that can be broadly divided into two distinct lineages with different functions, tissue-resident macrophages, which lack the cell surface receptors CCR2, and monocyte-derived macrophages with expressed cell surface receptors CCR2. We tested the hypothesis in this study that these macrophages that come with the donor heart remain active for a period of time after transplantation and play important roles in either suppressing or accelerating heart transplant rejection. Dr. Greg Hundley: What was the hypothesis that you wanted to address with your study? Dr. Kory Lavine: Yeah, so our prior work and others' work within this field had suggested that tissue-resident macrophages, CCR2-negative macrophages, are inflammatory, and CCR2-positive macrophages have the opposite functions being inflammatory and play roles in potentiating and initiating inflammation in the heart. In this study, we hypothesized that CCR2-negative macrophages would protect from rejection, while CCR2-positive macrophages may promote heart transplant rejection and could serve as a new therapeutic target to prevent rejection in transplant recipients. Dr. Greg Hundley: Excellent. Kory, can you describe for us the study design that you used to test your hypothesis? Dr. Kory Lavine: Yeah. The study design and approach we used involved a mouse model of heart transplantation where we transplant a donor heart into a recipient mouse that's fully mismatched at all the MHC loci, and this serves as a nice model for both cellular and antibody-mediated rejection. To facilitate tracking these donor macrophages, we used various genetic lineage tracing systems and, to study their phenotypes, we used single-cell RNA sequencing and, to understand their function, we used mouse models that allow us to specifically deplete each of the donor macrophage populations as well as genetic models to manipulate their activation and signaling. Dr. Greg Hundley: The outcome measures were going to be what? Dr. Kory Lavine: Yeah. The outcome measures for transplant rejection in this mouse model are allograph survival, so the survival of the transplanted heart. We're able to directly look at how much rejection is present by histopathology, and then we're able to observe various mechanistic features using detailed phenotyping such as single-cell RNA sequencing and T-cell activation assays. Dr. Greg Hundley: Very nice, Kory. Well, all, our listeners, we're very excited to hear what were your study results? Dr. Kory Lavine: We learned that donor macrophages are dynamic and they survive for a period of time after transplantation or eventually lost due to transplant rejection. When we phenotyped the macrophages that came from the donor heart, we learned that they remained transcriptionally distinct from immune cells that enter the heart that were derived from the recipients, and they had important and distinct functions. If we depleted the tissue-resident macrophages that were CCR2-negative, we observed reduced allograph survival and increased rejection. If we depleted CCR2-positive macrophages that came from the donor heart, we observed improved allograph survival and reduced rejection. Mechanistically, we learned that CCR2-positive macrophages are activated through a MyD88-dependent pathway and, if we inhibited MyD88 cytokines which controls the expression of pro-inflammatory cytokines and chemokines, we could prolong the survival of the donor heart for a very significant period of time, reduce rejection and prevent the development of T-cells that would attack the donor heart. From a mechanistic aspect, what we uncovered is that this signaling pathway in CCR2-positive macrophages regulated the recruitment of an activation of antigen-presenting cells which played important roles in generating T-cells that would target the transplanted heart. Dr. Greg Hundley: It sounds like a really informative and leap forward in the whole sphere of transplant rejection. Well, listeners, now we're going to turn to our associate editor, Dr. Thomas Eschenhagen. Thomas, you have many papers come across your desk. What attracted you to this particular paper and then, secondly, how do you put the results of this study really in the context of other research examining heart transplant rejection? Dr. Thomas Eschenhagen: Yeah, thanks for having me. I mean, first, we got attracted by this paper because it's somewhat an out-of-the-box approach. It's not the standard approach to improve the systemic immunosuppression as many studies did and with actually a lot of success over the last 30 years, survivor got much better. There had been a lot of progress in the field of transplantation medicine as we all know, but as Kory said already, we still have 30% rejection, and these immunosuppressions come at a price. Having this study which turns around somehow the argumentation and looks at the donor organ was something which really attracted us. It uses advanced methods and it applies somewhat in a practical way a concept which emerged over the last, I don't know, maybe decade this concept that macrophages are really very different kind of cells. They're all called macrophages, but they're quite different and even maybe in certain respects having opposing effect. I think many people know about this M1/M2 concept. It's CCR2 receptor positive and negative. It's criticized by some people, but here we see that it really seems to be really important and, of course, then the third argument why we really like the story is that it has a specific, clear translation impact. I mean, looking at the heart, the donor heart, and potentially even treating the donor heart before transplanting it is something which comes immediately out of the story, and that's something which we found super attractive. Dr. Greg Hundley: Really interesting, so really understanding the mechanism and focusing on donor hearts. Well, listeners, let's circle back with Kory. Kory, given that, what do you think is the next study that really needs to be performed in this sphere of research? Dr. Kory Lavine: I think Thomas said it exactly as we're thinking about it, so the next area that we're really excited to attack and we're hopeful that the field will focus on is ways to build methods and technologies to treat the donor heart between the time of procurement and the time of transplant, when it's being transported and potentially even being perfused for a period of time. We're really interested in finding approaches to identify small molecules and other potential biologic therapies that could be used to prevent the activation of donor CCR2-positive macrophages. It's a really attractive approach because treating the donor heart ex vivo decreases the risk of adversely affecting other organs that may be transplanted if you're treating the donor, for instance, and it may decrease the risk of immunosuppression and infection by not having to treat the recipient and we're catching the heart in this window where the risks are much lower. The other area that we're really excited to focus on is trying to identify the exact mediators that are generated from donor CCR2-positive macrophages that mediate the recruitment and activation of antigen-presenting cells because that would represent another potential therapeutic target. Dr. Greg Hundley: Very nice. Thomas, what are your thoughts about what might be the next study to be performed really in this sphere of research? Dr. Thomas Eschenhagen: It's obviously something rather a question to Kory than to me, but I agree to what he said. I think it is pretty obvious what are the next steps mechanistically on the one hand, but practically on the other hand. I mean, at this point, we are at the mouse level, so the question is to which extent can this concept be translated into larger animals and then finally in humans? I was wondering, given these newer methods to keep donor hearts alive for long, extended periods, I was wondering which extent you are already collaborating with the respective groups who develop this approach because that obviously would increase the window of opportunity here for drugs. I think it's really an exciting and pretty visible next steps which we see here, and I can just hope that you're going this path and that it will be successful. Dr. Greg Hundley: Kory, any thoughts on those collaborations that Thomas just spoke of? Dr. Kory Lavine: We're definitely establishing collaborations to focus on ex vivo profusion of donor hearts because that's, as Thomas mentioned, is a perfect window to manipulate the immune populations that are within the donor heart. Those studies have to be team science, they have to be collaborative and they have to have a focus on large animals and then moving into clinic. We're definitely forming those collaborations and excited to work as a group. Dr. Greg Hundley: Very nice. Well, listeners, what an exciting paper to discuss here as part of this feature discussion from the world of preclinical science. We want to thank Dr. Kory Lavine from Washington University in St. Louis, Missouri, and also our own associate editor, Dr. Thomas Eschenhagen from Hamburg Germany, for really bringing us this research study highlighting that distinct populations of donor and recipient macrophages coexist within the transplanted heart, and donor CCR2-positive macrophages are key mediators of allograph rejection and deletion of MyD88 signaling in donor macrophages is sufficient to suppress rejection and extend allograph survival. Well, on behalf of Carolyn and myself, we want to wish you a great week, and we will catch you next week on the run. Dr. Greg Hundley: This program is copyright of the American Heart association, 2022. The opinions expressed by the speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
Historically, echo analysis has been too expensive or inaccessible for many heart disease patients to receive the care they need. Today's guests, James Hare and Dr. Carolyn Lam of Us2.ai, are changing that. Us2 is a decision support tool that uses artificial intelligence to automate reading any DICOM (Digital Imaging and Communications in Medicine), anytime, from any device. It is FDA-cleared, vendor-agnostic, and delivers peer-reviewed results that are shown to be interchangeable with expert human sonographers. Us2's mission is to give everyone full access to their heart health with easy, mobile echo analysis. Today, James and Dr. Lam discuss why echos can be tricky even for medical experts to get right, how Us2 supports both physician and patient use across a variety of cardiac conditions and the healthcare democratization movement. Notable Quotes “It should be accessible to everybody to look at the heart. Why shouldn't you be able to look at the heart and see you've got a hole in your heart or a part of the heart that's not working well or a valve is not working well? I mean, we should be able to do that everywhere.” – Dr. Carolyn Lam (04:02) “There's a lot of well merited skepticism about new AI technologies and the burden is on us to prove that what we have done is useful and it works. But once we push beyond that, once people actually see it, it's just the best feeling in the world. And the reality is that everybody in this, as skeptical as they are, everyone knows what the future is. It's just a matter of how soon we're gonna get there.” – James Hare (18:37) In This Episode (03:36) Us2's origins (15:20) How it works (19:40) Use cases and the intricacies of heart failure that Us2 can identify (25:38) Us2 uses beyond heart failure (31:30) Us2's commercial outlook (33:25) The biggest challenge during Us2's development (35:13) Finding a shared language across business, medicine and tech (39:05) The future of Us2 in hospitals and physician offices Our Guests Us2.ai CEO and Co-founder James Hare previously served as the Co-founder and President of eDreams, which IPO'd in 2014 and has become one of the world's most successful e-commerce sites. Before starting Us2, James worked at organizations including EFI, UbiSoft and Netscape, and earned his MBA from Stanford and BA from Harvard. Dr. Carolyn Lam is the Co-founder & Non-Exec Head of Medical Affairs, and is a tenured Professor at Duke-National University in Singapore, where she founded and continues to run the first Women's Heart Clinic. Dr. Lam received her Masters from the Mayo Clinic, graduated from the Stanford Executive Program and then earned her PhD from the University Medical Center Groningen in the Netherlands. Resources & Links Mike Moore LinkedIn James Hare LinkedIn Dr. Carolyn Lam LinkedIn Us2.AI Website LinkedIn The Bleeding Edge of Digital Health Apple Podcasts Google Amazon Spotify YouTube LinkedIn
This week, please join author Philipp Lurz and Editorialist Daniel Burkhoff as they discuss the article "Characteristics of Heart Failure With Preserved Ejection Fraction Across the Range of Left Ventricular Ejection Fraction" and the editorial "HF?EF: The Mysterious Relationship Between Heart Failure and Ejection Fraction Continues." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-host. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: I just cannot wait to tell you about today's feature discussion, Greg. It's about heart failure with preserved ejection fraction and characteristics in the range of that ejection fraction that's above 50%. So, okay. I know, I know. It's like, "Oh my gosh. Wow. How much are we going to be talking about this ejection fraction thing?" But I'm telling you, everybody has to listen to this. It's really a big stride forward in our understanding of these patients with heart failure and a higher ejection fraction. Plus it includes one of my mentors from Mayo Clinic days, and I just can't wait for everyone to hear this. But before we go there, we've got really, really cool original papers in today's issue too. Would you like to start first? Dr. Greg Hundley: You bet Carolyn, and I can't wait for that feature discussion, especially this is a real area of your expertise. So listeners, hold on for that feature discussion. Well, my first paper, Carolyn, really pertains to physical activity. And Carolyn, the study is led by Dr. Don Hoon Lee from the Harvard T.H. Chan School of Public Health. And it evaluated a total of 116,000 adults from two large prospective US cohorts, the Nurse's Health Study and the Health Professional's Follow up Study that took place from 1988 to 2018. And they were examining self-reported leisure time physical activity and assessed the association between long term leisure time physical activity intensity and all cause and cause specific mortality. Dr. Greg Hundley: Now Carolyn, two types of physical activity were assessed. First, moderate physical activity and we're going to abbreviate that as MPA and that was 150 to 300 minutes per week, which is really recommended. Or second, vigorous physical activity for which it's really recommended that one performs 75 to 150 minutes per week. Now, Carolyn, as you know, some individuals accomplish both of these in their routine, some neither, some one or the other. And so it really remains unclear whether higher levels of long term vigorous or moderate are independently or perhaps jointly associated with lower mortality. Dr. Carolyn Lam: Oh, that's so interesting, Greg. Quick, quick, quick, tell us the results. Dr. Greg Hundley: Right Carolyn. So the nearly maximum association with lower mortality overall was achieved by performing approximately 150 to 300 minutes per week of long term leisure time vigorous physical activity or 300 to 600 minutes per week of long term leisure time moderate physical activity or an equivalent combination of both, so mixing those minutes. Also Carolyn, very interestingly, higher levels, suppose you go beyond those limits of either long term leisure time vigorous physical activity of more than 300 minutes per week or moderate physical activity of more than 600 minutes per week did not show clearly further lower all cause cardiovascular disease or non-cardiovascular disease mortality and nor did they show harm. So if you went above those thresholds, you really didn't experience greater harm. Dr. Carolyn Lam: Thanks, Greg. You know I'm going to be trying to apply that. That's so cool. All right. Well the next paper refers to the Cabana Trial, which I'll remind you is a trial in which catheter ablation did not significantly reduce the primary endpoint of death, disabling stroke, serious bleeding or cardiac arrest compared to drug therapy by intention to treat, but did improve quality of life and freedom from atrial fibrillation recurrence. In Cabana, the heart failure subgroup, ablation appeared to improve both survival and quality of life. The current paper led by Dr. Mark and colleagues from Duke Clinical Research Institute looked at the cost effectiveness of this ablation versus angio-rhythmic drug therapy in atrial fibrillation and which was a pre-specified Cabana secondary endpoint. Dr. Greg Hundley: Ah, Carolyn. So what did they find? Dr. Carolyn Lam: Well in this trial based economic evaluation, catheter ablation was estimated to cost $57,893 per QALY or Quality Adjusted Life Year gained compared to drug therapy in the overall cohort. And this was primarily driven by improvement in quality of life. It also cost $54,135 per QALY gained in the heart failure subgroup, driven by both gains in quality of life and survival. In summary, catheter ablation of atrial fibrillation was found to be economically attractive compared to drug therapy in the Cabana trial overall at present benchmarks of healthcare value in the US and based on projected incremental qualities, but not live years alone. Dr. Greg Hundley: Very nice Carolyn. Well, my next paper comes to us from the world of Preclinical Science and it's corresponding author is Dr. Swapnil Sonkusare from University of Virginia School of Medicine. So Carolyn, calcium signals in smooth muscle cells contribute to vascular resistance and control blood pressure. Now increased vascular resistance in hypertension has been attributed to impaired smooth muscle cell calcium signaling mechanisms. And in this regard, transient receptor potential vanilloid four or TRPV4 smooth muscle cell ion channels are crucial calcium entry pathways for smooth muscle cells. However, their role in blood pressure regulation has not been identified. Dr. Carolyn Lam: Wow. TRPV4 smooth muscle cells. Cool Greg. So what did they find? Dr. Greg Hundley: Right, Carolyn. So these authors provide the first evidence that TRPV4 smooth muscle cell channel activity elevates resting blood pressure in normal mice. A1AR stimulation activated TRPV4 smooth muscle cell channels through protein kinase calcium signaling, which contributed significantly to vasoconstriction and blood pressure elevation. Dr. Greg Hundley: Surprisingly, intraluminal pressure induced TRPV4 smooth muscle cell channel activity, opposed vasoconstriction through activation of calcium sensitive potassium channels indicating functionally opposite pools of TRPV4 smooth muscle cell channels. And so Carolyn, this team identified novel smooth muscle cell calcium signaling nano domains that regulate blood pressure and demonstrate impairment in hypertension. Dr. Carolyn Lam: Oh wow, Greg. Thank you so much for that. Well, let's cover the other articles in today's issue. There's a primer by Dr. Jaffe on High Sensitivity Cardiac Troponin and the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guidelines for the evaluation and diagnosis of acute chest pain. There's also Research [Letter] in there by Dr. Fordyce on the eligibility for non-invasive testing based on the 2021 American Heart Association and ACC guideline for the evaluation and diagnosis of chest pain, implications from the Promise trial. Dr. Greg Hundley: Great Carolyn. Well, I've also got an exchange of letters to the editor from Professors Benali and Professor Della Bella regarding a previously published article, “Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients with an Implantable Cardioverter Defibrillator, Results from the Multicenter Randomized Partita Trial.” And also there's a very nice Perspective piece from Dr. Udelson entitled “Glucose Insulin Potassium Therapy for Acute Myocardial Infarction, 50 years on and Time for a Relook.” Well, Carolyn, I can't wait to hear more of the discourse between you, the authors and editors on heart failure and preserved ejection fraction. Dr. Carolyn Lam: Yay. Here we go. I'm so excited about today's feature discussion. It's on my favorite topic, heart failure with preserved ejection fraction. Although thanks to one of the authors, Dr. Daniel Burkhoff of the editorial that accompanies it, I don't even know how to pronounce, it's Heart Failure question mark Ejection Fraction. I love it. How would you pronounce that? Dr. Daniel Burkhoff: Yeah, no, we debated how to pronounce it. HFQRef…a question mark? Dr. Carolyn Lam: HFQRef. Oh my goodness. What are we going to come up with next? Dr. Daniel Burkhoff: And we actually thought the editors would have a problem with that. Whenever we put something cute in the title, we always get knocked down. So we haven't yet got knocked down, so we'll see. Dr. Carolyn Lam: No, I'm not knocking you down. Dr. Daniel Burkhoff: But it just really emphasizes that we're in a very confusing time now as it comes to heart failure and ejection fraction, that we have to move on beyond ejection fraction. And although we have these strict buckets and upper and lower limits for each range, that maybe this is in a little bit of a way, doing us a disservice and doing the patients at disservice in terms of treatment. Dr. Carolyn Lam: That's really great. And everybody that was Dr. Daniel Burkhoff from the Cardiovascular Research Foundation in New York. He's the editorialist of today's feature paper. And I'm so excited that we have the corresponding author of today's feature paper as well, Dr. Philipp Lurz from Heart Center Leipzig in Germany. So first, I mean, or second, heartfelt congratulations on this beautiful paper, Philipp. If you could start with telling us all about what you did and what you looked at and what made Dr. Daniel Burkhoff call it now, Heart Failure, QREF? Dr. Philipp Lurz: Yeah. So thank you so much, first of all, obviously for having me for the kind introduction and your kind words about our work. The whole thing started with the observation that in recent drug trials, the response in HFpEF patients to drugs which were before proven to be quite successful in HFrEF actually showed a quite heterogeneous response in HFpEF patients. And that there were some patterns according to the range of ejection fractions. So it seemed that those HFpEF patients with the lower ejection fractions, they respond a little bit better to HFrEF medication than those with a higher ejection fraction. Dr. Philipp Lurz: And HFpEF studies, they included patients within and ejection fraction or 40 and above who normally would probably would consider HFpEF to start with 50 and above. But even in those truly HFpEF patients, so from 50 and anything above to 70, there was a suggestion that there might be differences. 50 to 60 might be something else and then 60 and above. And this is where we started to look into our cohort and to group them according to ejection fraction and see whether we can see some important and clinically meaningful differences in morphology, obviously in function, but then even also in terms of our biopsy results. Dr. Philipp Lurz: And that also implies that we did quite a deep phenotyping of our patients. So we use imaging, echo obviously. We use magnetic resonance imaging. We were able to acquire in a larger percentage of that cohort, by the way, it was 56 patients in total, we were able to get some left ventricular biopsies. And most importantly, when it comes to the functional properties of the left ventricle, we also acquired pressure volume loops. And that has the great advantage that we obviously we can look at low dependent parameters, but more important, also low independent in disease of both systolic and diastolic function. And that's pretty much what we did. Dr. Carolyn Lam: Oh my goodness. I mean, as an editor at Circulation, can I just first tell you that's what really, really stood out? It's the comprehensive, careful, in-depth characterization. It may be 56 patients, but MRI, echo, biopsies, exercise, PV loops. I mean, it was a lot, a lot that you did. Could you boil it down to what you found and maybe just to first clarify to the audience, how did you bend the ejection fraction? And then what you found? Dr. Philipp Lurz: We divided the cohort in two groups. One with an ejection fraction 50 to 60, and the other groups higher than 60% left ventricular ejection fraction. We ended up in lower group, 21 patients, in the higher group with 35 patients. And they were quite different. They had distinct features in terms of morphology, means that the lower injection fraction group, they had larger ventricles. That's probably what you would expect when you group them according to eject fractions. So not that surprising. Dr. Philipp Lurz: And at that point, and they had the same stroke volume. The low ejection fraction group, you could say that they had a certain degree of eccentric modeling, whereas those were the high ejection fraction group, that concentric modeling. When we then looked at the biopsies, the group with the low ejection fraction group, so 50 to 60, they had higher percentage of myocardial fibrosis at 15%. Dr. Philipp Lurz: And then on left ventricular biopsy, we saw that patients with a high ejection fraction group, they had less myocardial fibrosis, so more fibrosis in those with the lower ejection fraction group. And this is really interesting because when we then look at the real size of the pressure volume loop analysis, despite the fact that the high ejection fraction group had less fibrosis, they had the most stiff ventricles on pressure volume loop analysis. So that's already a very important point because it illustrates once again that we should not mistake fibrosis with stiffness, and also not the other way around. There are other parameters which can cause stiffness such as cellular stiffness, and it's not just the extracellular matrix. Dr. Philipp Lurz: So that's an important point. Those patients with high ejection fraction, they had the most stiff ventricles. They had the most relevant limitations in left ventricular filling, so the most marked diastolic dysfunction. We also looked at systolic parameters and there we found that they had a very high contractility. So this is the end systolic pressure volume relationship or also called elastics and that's a marker for contractility. So these ventricles with high ejection fraction, they can contract very well. They have high contractivity. But this is also a marker of systolic stiffness. So they stiff, both in terms of diastolic properties, but also systolic properties. And there, their most important limitation is the limitation in filling. Dr. Philipp Lurz: The other group, injection fraction 50 to 60, they do have some stiffness. Obviously we are talking about HFpEF. This is a disease of a diastolic dysfunction. So they have increased stiffness, but to a lesser extent. They can feel a little bit better, but what we see there is a reduction in contractility, so systolic properties. So you could argue that in some extent, that group 50 to 60, they behave a little bit more like HFrEF. Whereas those with high ejection fraction, they're completely different. Very stiff, both doing diastolically and sistolly. Dr. Carolyn Lam: Thank you so much. Now I really have to get the gurus insight into this. And of course by guru, I mean, Dr. Daniel Burkhoff. First, I'm going to take this opportunity to share a little private personal story that it's very hard for me to call Dr. Burkhoff, "Dan", although if you will allow me it's because I was a fellow when I first met Dr. Burkhoff. And one of my first papers was actually communicating with Dr. Burkhoff trying to draw these PV loops based on the noninvasive measurements that I was obtaining at the Mayo Clinic in the Olmsted County Cohort. And so this is just really making me smile. So Dan, if I may, what do you make of all this? And if you could give us what you think may be the clinical take home message. Dr. Daniel Burkhoff: Thank you so much, Carolyn. And also again, Philipp, congratulations on really a really important paper. I think as Carolyn was saying, one of the many things that impressed me was the multifaceted aspects of the thorough evaluation using multi modality characterization, which is in my mind, unprecedented, especially for this particular group of patients. And you summarized the main results very well. But to me, the thing that really struck me and that we really tried to emphasize in our editorial was the differential response to exercise, to hand grip exercise in this point. Dr. Daniel Burkhoff: As you already said, and I don't think this could be understated, that in the lower range, the 50 to 60, these patients were able to fill, the ventricle was able to fill more, the end diastolic pressure still went up significantly into an abnormal range, which is of course is one of the requirements for the diagnosis of HFpEF. But those patients, the end diastolic volume was able to increase and that helped them to increase their cardiac output. Dr. Daniel Burkhoff: In the higher EF group, the greater than 60, the end diastolic pressure went up, but the volume did not increase. So the end diastolic pressure volume relationship became higher elevated. And this of course, was reminiscent of what was identified in the early nineties by Dalane Kitzman. And really, he didn't make this distinction between the lower half and the higher half. And we had also in a paper that we did with David K and others, seen a similar finding a couple years ago. And I think this is really, to me, was the along with the apparently disparate findings on myocardial biopsies with fibrosis going the wrong way, if you will, as you already commented on. So this is at least for the higher EF group, is identifying what I would refer to as really true diastolic dysfunction. Dr. Daniel Burkhoff: That means that the patients can't fill, there really is some problem why the EDP can go up, but the volume does not increase. And this is obviously for future research, we have to understand what is the difference between these two groups. There are several speculations about why it might. For example, one thing that has been proposed in the literature is the pericardial restraints. If the heart is constrained in a tight pericardium, the volume is recruited from the venous system, which is another what I think is a very important part of this HFpEF phenotype, but the heart is already constrained. That would elevate both the CVP and the wedge pressure without concomitant increases in RV or LV volumes, and therefore limit the ability to increase the cardiac output. Dr. Daniel Burkhoff: Another alternative is delayed relaxation. That means a true abnormality of active relaxation. The tau if you will, but I believe in your study, if I remember correctly, the tau was not that abnormal and did not really change very much in either group. So it was harder to really pin it on an abnormality of active relaxation. So that was one really, I think, really important finding. Dr. Daniel Burkhoff: The second is now in the group 50 to 60 where they could fill, one of the limitations of the study that you pointed out was that there's no control group. So why this population, this HFpEF population, the EDP increased, but the EDV the end diastolic volume also increased, so what's different between those patients and normals? That we don't really have an answer for yet. So that would be one thing is to compliment these findings with results in a true control group that does not have HFpEF. Dr. Daniel Burkhoff: So we still have this mystery of why does EDP go up in this group? My perspective is not an abnormality of diastolly. It's not a diastolic dysfunction, even though it's a HFpEF. I've been trying to promote this idea for more than 20 years, that all HFpEF is not an abnormality of diastolic ventricular properties. There may be extra cardiac factors even beyond the pericardium in this group. So I think these results are just further telling us how complicated and individualized our approach to the pathophysiology of these patients should be. Dr. Daniel Burkhoff: And also just one final comment, making a strict cutoff at 60% or 57% as we saw from Valsartan Cuba trial, Valsartan study, is clearly also not going to do us justice. Let's say that we're dealing with anyway, patients with two different pathophysiologies. There's going to be a distribution of these different mechanisms and there's going to be an overlap of these distributions. So we need to start thinking about how we individualize and characterize the pathophysiology in individual patients. So maybe patients with EF of 55, certain patients with EF 55 will not respond to Sacubitril- Valsartan and maybe some patients with an EF of 62 will. So we need to go more deep into the clinical characterization. Dr. Daniel Burkhoff: And methods that you use in particular, the pressure volume loop, seem to separate, very nicely, these two different, at least two different subtypes. So I think it's very exciting, and I think people should really take notice of what you found and build on this as a foundation and understand that we need to go deeper on the clinical side to phenotype these patients. Dr. Carolyn Lam: Philip, what are your thoughts? Dr. Philipp Lurz: No, I think that the concept about stress and unstressed volume is extremely important and fascinating, but that's where it gets really complex because you could make the conclusion from our results that especially the high ejection fraction group, they are have a very high preload sensibility, which means that when we reduce pre-load too much in them, they drop the stroke volume very suddenly. So that's probably also the clinical question for the future. There are many patients, HFpEF patients in whom we should reduce stress volume and they can benefit from that. Dr. Philipp Lurz: But I also believe that there is a cord of patients, and those are probably more those with high ejection fraction. They actually, they could experience some harm if you reduce preload too much because of the severe filling restrictions, because of the inability to increase end diastolic volumes, especially as an adaptation to exercise. And I think if we find out ways to differentiate who will benefit from preload reduction and from decongestion and who actually might experience even harm from these interventions, then we are certainly one step further. Dr. Carolyn Lam: If I may, I just, I could go on forever, but I know that there's going to be this question that the audience is immediately thinking. Here we are going into the weeds, hemodynamics, we all love it. In fact, I think we're all kind of a little bit geeky about it, but then you've got, Emperor preserved, the Deliver Trial sort of being positive in heart failure with ejection fraction above 40. So, do we really need to understand the different hemodynamic? What do you think is happening that this sort of blanket benefit can occur? Dr. Philipp Lurz: I don't think that everyone will benefit. And I think that a better understanding of the underlying pathophysiology will help to even increase the rate of responders and dissect of those who will not respond or we need a different therapy. Obviously here we group patients according to ejection fraction. We just discussed that this is a very rough way to characterize patients. So the next step certainly would be to understand or to see distinct patterns in left ventricular functional behavior irrespective of ejection fraction. Because you might can skip ejection fraction at one day, but the conclusion is not, at least not in my opinion, that all heart failure is the same. Dr. Carolyn Lam: Nice. And Dan, what do you think? Dr. Daniel Burkhoff: Well, I think with STLT2 inhibitors, first of all, we're looking forward to actually seeing the results from Deliver what the details of it in terms of mortality versus hospitalizations and quality of life. But with regard to HSGL2 inhibitors, I don't think we know the mechanism. I mean, I've read about six papers that definitively talk about different mechanisms of action. I think we don't know. And even despite, let's say positive studies, there's still a significant residual risk that these patients have. So these are not the end of the story by any means. I think this is the beginning of the story and there's still going to be a lot to learn. Dr. Daniel Burkhoff: I think with SGLT2 inhibitors, I think it's difficult to identify who is or how do you define a responder on an individual patient basis? When we look at groups and you look at mortality and hospitalizations, yes, you can identify them. But that group does not overlap exactly with those who have an improvement in quality of life. So I think that we're just at the beginning, Dr. Daniel Burkhoff: I do think that a deeper phenotyping is going to be the way to go ultimately and I think we're going to need more therapies. Thanks again, Carolyn for inviting me to do the editorial and to participate in this. And I would really be remiss if I did not mention the extraordinary contributions for Mickey Brener and also Barry Borlaug who were equal contributors to this editorial and the evaluation of this paper. So I'm really indebted to both of them for this interpretations. And thank you again, Philipp, for just a wonderful paper. Dr. Carolyn Lam: Couldn't have said it better and I just want to thank you once again for providing that deeper phenotyping for opening the door. Many of us said it again and again, this is the beginning and we need more studies, frankly, in yours. I mean, I think Dr. Burkhoff wants you to send normal, healthy people for MRI biopsies, exercise, echo. I'm kidding, on PV loops, but it's true. We need that data. We need the same and the HFrEF and really just to understand the whole thing. I'm so excited about what this paper opens up. Dr. Carolyn Lam: I am thrilled to see your editorial, Dan. I'm sure it's going to be well received. Everyone who's listening to this, Pick up the paper, pick up the editorial. Thank you so much for joining us today. You've been listening to Circulation on the Run and from Greg and I, don't forget to tune in again next week, Dr. Greg Hundley: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit hajournals.org.
This week, please join authors John McMurray and David Cherney, editorialist Kausik Umanath, as well as Associate Editors Ian Neeland and Brendan Everett as they discuss the original research articles "Initial Decline (Dip) in Estimated Glomerular Filtration Rate After Initiation of Dapagliflozin in Patients With Heart Failure and Reduced Ejection Fraction: Insights from DAPA-HF" and "Renal and Vascular Effects of Combined SGLT2 and Angiotensin-Converting Enzyme Inhibition" and editorial ""Dip" in eGFR: Stay the Course With SGLT-2 Inhibition." Dr. Carolyn Lam: Welcome to Circulation On the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-hosts, I'm Dr. Carolyn Lam, Associate Editor from the National Heart Centre and Duke National University of Singapore. Dr. Greg Hundley: I'm Dr. Greg Hundley, Associate Editor and director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, it's the season of double features. Except this time, we're having a forum discussion of two related articles and an editorial that discusses both. What is it on? SGLT2 inhibitors. In the first paper, an analysis from the DAPA-HF trial, looking specifically at that initial dip in GFR that follows initiation of dapagliflozin in patients with HFrEF. Then we will discuss further, in a mechanistic way, the renal and vascular effects of combining SGLT2 inhibition on top of ACE inhibition. Lots and lots of good learning and insights, but let's go on first to the other papers in today's issue. Shall we? Dr. Greg Hundley: You bet, Carolyn, and I'm going to grab a cup of coffee. Carolyn, in this issue, wow, so many exciting original articles. In fact, there are two more articles that were going to pair together, both clinical and pertaining to TAVR procedures. In the first one, it was a group of authors led by Dr. Duk-Woo Park from the Asan Medical Center at the University of Ulsan College of Medicine. They conducted a multicenter, open-label randomized trial comparing edoxaban with dual antiplatelet therapy or DAPT, aspirin plus clopidogrel, in patients who had undergone successful TAVR and did not have an indication for anticoagulation. Now in this study, Carolyn, the primary endpoint was an incidence of leaflet thrombosis on four-dimensional computed tomography, CT, performed at six months after the TAVR procedure. Key secondary endpoints were the number and volume of new cerebral lesions on brain magnetic resonance imaging or MRI and the serial changes of neurological and neurocognitive function between six months and that time immediately post the TAVR procedure. Dr. Carolyn Lam: Oh, interesting. What did they find? Dr. Greg Hundley: Right, Carolyn. In patients without an indication for long-term anticoagulation after successful TAVR, the incidence of leaflet thrombosis was numerically lower with edoxaban than with dual antiplatelet therapy, but this was not statistically significant. The effect on new cerebral thromboembolism and neurological or neurocognitive function were also not different between the two groups. Now because the study was underpowered, the results should be considered really as hypothesis generating, but do highlight the need for further research. Dr. Greg Hundley: Carolyn, there's a second paper pertaining to transcatheter aortic valve prosthesis. It's led by a group directed by Dr. Paul Sorajja from the Minneapolis Heart Institute Foundation and Abbott Northwestern Hospital. Carolyn, these authors prospectively examined 565 patients with cardiac CT screening for HALT, or what we would define as hypoattenuating leaflet thickening, at 30 days following balloon-expandable and self-expanding TAVR. Now, deformation of the TAVR prosthesis, asymmetric prosthesis leaflet expansion, prosthesis sinus volumes, and commissural alignment were analyzed on the post-procedural CT. For descriptive purposes, an index of prosthesis deformation was calculated, with values greater than 1 representing relative midsegment underexpansion. A time-to-event model was also performed to evaluate the association of HALT with the clinical outcomes. Dr. Carolyn Lam: Oh, interesting. What did they find? Dr. Greg Hundley: Right, Carolyn. Nonuniform expansion of TAVR prosthesis resulting in frame deformation, asymmetric leaflet, and smaller neosinus volume was related to the occurrence of HALT in patients who underwent TAVR. What's the take home here, Carolyn? These data may have implications for both prosthesis valve design and deployment techniques to improve clinical outcomes in these patients. Now, Carolyn, both of these articles are accompanied by an editorial from Dr. Raj Makkar from the Smidt Heart Institute at Cedars-Sinai's Medical Center. It's a very lovely piece entitled Missing Pieces of the TAVR Subclinical Leaflet Thrombosis Puzzle. Well, how about we check what else is in this issue? My goodness, this was a packed issue. First, Carolyn, there are three letters to the editor from Professors Ennezat, Dweck, and then a response from Dr. Banovic pertaining to a follow-up from a previously published study, the AVATAR study, in evaluating valve replacement in asymptomatic aortic stenosis. There's also a Perspective piece from Dr. Wells entitled “Treatment of Chronic Hypertension in Pregnancy: Is It Time For A Change?” There's a Global Rounds piece from Professor Berwanger entitled “Cardiovascular Care in Brazil: Current Status, Challenges, and Opportunities.” Then there's also a Research Letter from Professor Eikelboom entitled “Rivaroxaban 2.5 mg Twice Daily Plus Aspirin Reduces Venous Thromboembolism in Patients With Chronic Atherosclerosis.” Dr. Carolyn Lam: There's another Research letter by Dr. Borlaug on longitudinal evolution of cardiac dysfunction in heart failure with normal natriuretic peptide levels. There's also a beautiful Cardiology News piece by Bridget Kuehn on the post-COVID return to play guidelines and how they're evolving. Well, that was a great summary of today's issue. Let's hop on to our feature forum. Shall we? Dr. Greg Hundley: You bet, Carolyn. Can't wait. Dr. Carolyn Lam: Today's feature discussion is actually a forum because we have two feature papers in today's issue. They all surround the cardiorenal interaction, should I say, of the SGLT2 inhibitors. For the first paper, discussing that initial decline or that dip in the GFR following initiation of dapagliflozin would be Dr. John McMurray, who's the corresponding author of this paper from DAPA-HF. Dr. John McMurray's from the University of Glasgow. Now next, we have also the corresponding author of another paper, really going into the mechanistic insights of the renal and vascular effects of combined SGLT2 and ACE inhibition. Dr. David Cherney is from Toronto General Hospital, University of Toronto. Dr. Carolyn Lam: We have the editorial list of these two wonderful papers, Dr. Kausik Umanath from Henry Ford Health in Michigan. Finally, our beloved associate editors, Dr. Ian Neeland from Case Western Reserve and Dr. Brendan Everett from Brigham and Women's Hospital, Harvard Medical School. Thank you, gentlemen. Now with all of that, what an exciting forum we have in front of us. Could I start by asking, of course, the respective authors to talk a little bit about your papers? I think a good place to start would be with Dr. McMurray. John, please. Dr. John McMurray: Thanks, Carolyn. I think our paper had three key messages. The early dip in eGFR that we saw was, on average, very small in patients with heart failure, about 3 mLs/min or about 5%. Very few patients had a large reduction in the eGFR. It was around 3%. Dapagliflozin-treated patients had a 30% or greater decline compared to about 1% of placebo patients. Finally, very few of those patients had a decline in the eGFR below a critical threshold, which for cardiologists might be around 20 mLs/min. We saw that in only five patients; that's 0.2% of the dapagliflozin-treated patients. Second message was that that early decline partially reverses. The nadir in our study was about 14 days. But by 60 days, on average, eGFR had increased again. Hold your nerve if you see an early decline in eGFR. Dr. John McMurray: Maybe the most important message was that that decline in the eGFR is not associated with worse cardiovascular or renal outcomes. In fact, if anything, the opposite. If you look at the patients in the dapagliflozin group with a 10% or greater decline in eGFR, then compare it to patients who didn't have that decline, these individuals were about 27% less likely to experience the primary composite outcome of worsening heart failure and cardiovascular death. If you look at the placebo group, we saw exactly the opposite. Amongst those who had a greater than 10% decline in eGFR compared to those who didn't, those people with the early decline in eGFR were 45% more likely to experience the primary composite endpoint. The same is true for other cardiovascular outcomes for worsening kidney function. In the dapagliflozin group, decline in eGFR was not associated with more adverse events, not associated with more treatment discontinuation. That small decline in the eGFR is not a bad prognostic sign. If anything, it might be the opposite. Dr. Carolyn Lam: Thank you so much. That was really clear. David, are you going to tell us why this decline occurs? Dr. David Cherney: Yeah. Perhaps the paper that we published gives some insights into the mechanisms that are responsible for some of those changes in GFR that are thought to be acute hemodynamic effects. In the between trial, which is the trial that we published examining the effect of ACE inhibition followed by SGLT2 inhibition in patients with type 1 diabetes, we also saw that there was an expected effect of adding SGLT2 inhibition on top of an ACE inhibitor in people with uncomplicated type 1 diabetes. This acute dip in GFR was seen in this cohort of patients. We included only 30 patients in this small mechanistic study. At the same time, along with that dip in GFR, we also saw an increase in measures of proximal natriuresis. That proximal sodium loss is linked with changes in sodium handling in the kidney, which then causes changes in both probably afferent and efferent tone, which causes this dip in GFR primarily through natriuresis in this phenomenon called tubuloglomerular feedback. That was one major observation that gives insight into what we see in larger trials around the dip in GFR. Dr. David Cherney: In our mechanistic study, we also saw an additive effect on blood pressure. Blood pressure went down further with the addition of empagliflozin on top of an ACE inhibitor. In terms of the mechanisms that are responsible for the reduction in blood pressure, natriuresis certainly may be in part responsible, but we also saw a novel observation whereby there was a reduction in peripheral vascular resistance using noninvasive measures. There are likely several mechanisms that are responsible for the reduction in blood pressure. Then finally, we also saw reductions in markers of oxidative stress, which may also account for some of the effects that we see in blood pressure, as well as potentially some of the anti-inflammatory and anti-fibrotic effects that we see at least in experimental models that may have some clinical translatability to humans as well around the clinical benefits. I think the blood pressure, the renal hemodynamic effects, and some of the neurohormonal mechanisms are the major observations that we saw that may in part explain some of the really nice changes that were seen in Dr. McMurray's study. Dr. Carolyn Lam: Right. Thanks, David. But these were patients with type 1 diabetes and no heart failure. John, do you have any reflections or questions about how that may apply? By the way, what a beautiful study. Thank you, David. Dr. David Cherney: Pleasure. Thank you. Dr. John McMurray: Yes, David. I really enjoyed your study. In fact, I think, Carolyn, it does shed some insights perhaps to what's going on. As David pointed out, the reduction in peripheral arterial resistance, reduction in blood pressure, that may play some role in that early dip in eGFR as well as autoregulation in the kidney. Then the other interesting thing is that the distal nephron seems to adapt to that effect in the proximal tubule. Again, that may account for some of that recovery in eGFR, that reversal in the early dip that I spoke about, and which I think is very clinically important because, of course, physicians should make sure that they recheck eGFR if they see that early dip. Because they may find that few weeks later that that dip is much smaller and of much less concern. Dr. Carolyn Lam: Thank you, John. In fact, you're saying, stay the course, right- Dr. John McMurray: I have. Dr. Carolyn Lam: ... with the SGLT2 inhibitors. I'm actually stealing the words of the title of the editorial, a beautiful editorial by Kausik. I love that. Stay the course. Kausik, please, could you frame both papers and then with an important clinical take home message for our audience? Dr. Kausik Umanath: Sure. I think the analysis by John and his group was really relevant with the large sample size. What's impressive? Similar to a lot of these other SGLT2 studies that have come out, both in heart failure and in kidney disease progression and so on, it's remarkable how the other analysis, like the analysis of EMPA-REG and CREDENCE and so on, of similar dips. All show more or less the same magnitude, the same relative proportions of this GFR trajectory. I think the mechanistic study only highlights that though it's working with a slightly different population of type 1 patients and much earlier in their course in terms of where their GFRs are. Dr. Kausik Umanath: The other piece is that ultimately we need to understand this dip and know to monitor for it and so on. But I think the general clinician should really understand that a dip of greater than 10% really occurs in less than half the population that takes these agents. That dip, if it occurs, certainly doesn't do any harm. That said, if they see a bigger dip in the 30% range, monitor more closely and consider making sure that there aren't any other renal issues out there for that patient because they are a much smaller proportion of patients in these large trials that generate that level of dip. They should be monitored. Dr. Kausik Umanath: The other thought that we had, and thinking through this in a practical sense, is because you expect this dip, many of our cardiologists or even the nephrologists when we titrate these drugs, they're on a suite of other drugs. It's probably best to not adjust their Lasix or their loop diuretic, or their RAAS inhibitor at the same time as you're adjusting the SGLT2 inhibitor or starting it because then you may just introduce more noise into the GFR changes that you see over the next several weeks. It may be a sequential piece or at least holding those other agents constant while this gets titrated and introduced is a prudent course of action, so you don't misattribute changes. Dr. Carolyn Lam: Thanks so much. What clinically relevant points. In fact, that point about the diuretic especially applies in our heart failure world. You see the dip. Well, first, make sure the patient's not overdiuresed. Remember, there's more that the patient's taking. Thank you. That was a really great point. Brendan and Ian, I have to get you guys to share your views and questions right now. But before that, can I take a pause with you and just say, aren't you just so proud to be AEs of Circulation when we see papers like these and we just realize how incredible the data are and the clinical implications are? I just really had to say that. All right. But with that, please, what are your thoughts, Brendan? Dr. Brendan Everett: Yeah, sure. Thank you, Carolyn. Hats off to all three of our authors today for doing some amazing science. Thank you for sending it to Circulation. I think, in particular, I handled David's paper. I'm not a nephrologist and I'm probably the furthest thing from a nephrologist. Had to do my best to try and understand these concepts that I'm not sure I ever even was exposed to in medical school many years ago. I think it shows the breadth of the interest in our readership. The fact that these changes in eGFR have become a primary focus for our cardiovascular patients and that the clinical implications are really important. I guess my question, David, is... In your paper, you talked a little bit about this hypothesis of hyperfiltration and the role that hyperfiltration plays in setting patients with diabetes up for kidney disease. Is that playing a role in John's observation or not? Again, as a non-nephrologist, I have trouble connecting the dots in terms of that hypothesis and John's observation of the clinical benefit for patients that have a reduction in eGFR as opposed to no change. Dr. David Cherney: Yeah. It's a great question. It's very difficult to know with certainty in a human cohort because we can't measure the critical parameter, which is intraglomerular pressure, which we think these changes in GFR are a surrogate for. But if we go along with that train of thought, along reductions in glomerular hypertension, it very much makes sense that the patients who dip are those who have the... They're taking their medication, number one. Number two, they respond physiologically in the way that you expect them to, which is that their GFR dips at least transiently and then goes back up again through some of the compensatory mechanisms that John mentioned earlier. As was mentioned not only in this paper, but also in previous analyses from CREDENCE and previous analyses from VERTIS CV and others have shown that indeed that dip in GFR is linked with longer term renal benefits, at least. That is reflected in a reduction in the loss of kidney function over time. Dr. David Cherney: The patients who are on an SGLT2 inhibitor and those who dip by around 10% or less, those patients tend to do the best over time in terms of preserving GFR, not losing kidney function compared to patients who are on an SGLT2 inhibitor but do not dip, or those patients who actually have an increase in GFR. That is consistent with this idea that there may be a reduction in glomerular pressure, which is protective over the long term. That ties back into your question around hyperfiltration that this may indeed be due to a reduction in glomerular pressure, which is linked with risk over the long term. Dr. Carolyn Lam: Ian? Dr. Ian Neeland: I wanted to echo Brendan's comments about the excellent science. When I read these papers, it really speaks to the existential struggle that cardiologists have between kidney function and these medications that we know have cardiovascular benefits. How do we manage that practically? It's so clinically relevant, both the observation that John's paper made about the dip in the DAPA-HF trial as well as, David, your mechanistic insights. Dr. Ian Neeland: I wanted to ask John potentially about the most fascinating aspect to me of this paper was that patients with a dip of 10% or more actually ended up doing better in terms of cardiovascular outcomes, specifically hospital heart failure and hospitalizations than people on placebo with a greater than 10% dip. It speaks to the fact that... Is the physiology going on here different between those individuals whose GFR went down on placebo versus those who are on SGLT2 inhibitors? All the mechanistic insight that David's paper had in terms of blood pressure and intraglomerular pressure, how does that feedback and speak to why heart failure is strongly linked to this mechanism? We see this not just with SGLT2 inhibitors, but there are other medications now coming out showing that there's a relationship between this dip in GFR and heart failure. Can you speak to why this heart failure-kidney connection is so important and becoming greater and greater in terms of our understanding? Dr. John McMurray: Well, thank you for asking me the hardest question and one that I truly don't think I have a good answer to. I think it's obvious to all of us that the kidney is central in heart failure and perhaps cardiologists have neglected that fact, focusing more on the other organ. But by definition, almost the fluid retention that characterizes heart failure in terms of signs, and probably is the primary cause of symptoms, that clearly is a renally-mediated phenomenon. The kidney must be central to all of this. I think David right. I think the decline in eGFR that you see with this drug is simply a marker that the drug is having its physiological effect or effects. Whatever those are, they're beneficial. Clearly, patients who have an eGFR decline on placebo are different and they reflect, again, the patients that we see all the time. As our patients with heart failure deteriorate, one of the things that we commonly see, in fact becomes one of the biggest problems that we have to deal with, is that their kidney function declines. As their symptoms get worse, as their cardiac function gets worse, their kidney function also declines. Dr. John McMurray: I think you're seeing two contrasting effects here. One is the background change in eGFR, which is the placebo patients, and we've always known that that's a bad thing. Then we're seeing that early within 14 days marker of the pharmacological or physiological action of the drug. I hope you don't ask me how SGLT2 inhibitors work in heart failure. That's the other most difficult question I can think of, but I think this is just a marker of the fact that they are working. Dr. David Cherney: Yeah. Just to add to that briefly, there is this difficulty in sorting out the mechanisms that are relevant around the acute effects in the kidney that the dip in GFR reflects natriuresis that could keep patients out of heart failure; that the reduction in glomerular pressure reduces albuminuria. Albuminuria reduction is linked with kidney protection. It's linked with heart failure and ASCVD protection. Then there's also this concept of if you dip and then you stay stable afterwards, your GFR stays stable afterwards, those patients with stable kidney function that's not declining, the dippers in other words, those patients are probably able to maintain salt and water homeostasis better than someone who's declining more rapidly. All these things probably tie together in order to reflect, of course, there's a renal protective effect, but that some of those mechanisms may also tie into the heart failure mechanisms that John was mentioning. Dr. John McMurray: But, David, it's hard to imagine if we don't protect the kidney, we won't protect patients with heart failure given how fundamental, as I said, the kidney is, and how fundamentally important worsening kidney function is. Not only because it is a marker of things going badly, but also because it often results in discontinuation or reduction in dose of other life-saving treatments. To Kausik's point, it was very important about the risk of changing background life-saving disease modifying therapy. Actually, we didn't see that in DAPA-HF, which was very intriguing. There was no reduction in use of renin-angiotensin system blockers or mineralocorticoid receptor antagonists. Dr. Carolyn Lam: Thank you so much, gentlemen. Unfortunately, we are running out of time, but I would really like to ask one last question to the guests, if possible. Where do you think the field is heading? What next? What's the next most important thing we need to know? David, do you want to start? Then John, then Kausik. Dr. David Cherney: I think one of the aspects that we need to know in the future is where else can we extend these therapies into novel indications and extend the boundaries of where we currently work with these therapies. People with type 1 diabetes, for example, with either heart failure or with significant kidney disease, patients with kidney transplantation, is there a renal or cardiovascular protective effect? Then another high risk cohorts who have not been included in trials, those on immunosuppressants, for example, who were excluded from the trials. I think those are some of the areas that we need to extend into now that we understand how these therapies work in even very sick patients and that we also know that they likely have at least some benefit through suppressing inflammation, and possibly reducing infectious risks. That would provide a rationale for extending into some of these new areas. I think that's certainly, hopefully on the horizon for us. Dr. Carolyn Lam: John? Dr. John McMurray: Carolyn, obviously I think looking at post myocardial infarction population, that's an obvious place to go. There are a couple of trials there. I suppose the trial that I would love to see, and which I think would address the core question that we've been discussing today, which is: Is this all about the effect in the kidney and how important is the diuretic and natriuretic action of these drugs in heart failure? I think the key study that would address this would be doing a study in patients on dialysis. Because in those patients we could, I think, separate the issue of natriuresis, diuresis, and maybe even the dip in EGR that we've been talking about. If these drugs prove to be effective in end-stage kidney disease, patients on dialysis, that would be really fascinating. Dr. Carolyn Lam: Kausik? Dr. Kausik Umanath: That is a very interesting point. I don't know that we know necessarily outcomes, but I think from working with the DAPA-CKD, we do have a little bit of the safety data because we did continue it. I was the US MLI for that study and we did continue the SGLT2 passed into renal failure. There is a little bit of safety data there. But I don't think once you've declared an outcome, you're not collecting outcomes data after that point. That's a very interesting area to look into. Dr. Kausik Umanath: I also think the other place where this field's heading is trying to better tier and layer the multitude of agents. I think we've been waiting for about 20 to 30 years, at least in the kidney field, for something new to affect the progression of kidney disease after the ACE/ARB trials and so on. This one we've got SGLT2 inhibitors. We've got the new MRA, finerenone, and so on, which also have very beneficial cardiovascular effects. The question becomes: How do we layer these therapies? Which sequence to go in? Some of the others that are in pipeline as well that are out there that have very beneficial cardiovascular effects that may indeed also help kidney function and diabetes control, which do you go with first and so on? Dr. Carolyn Lam: Wow! Thank you so much. We really could go on forever on this topic, but it has been tremendous. Thank you once again. On behalf of Brendan, Ian, Greg, thank you so much for joining us today in the audience. You've been listening to Circulation On the Run. Don't forget to tune in again next week. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join authors Paul Ridker and Eric Van Belle, editorialist Robert Harrington, and Guest Editor Allan Jaffe as they discuss the original research articles "Effects of Randomized Treatment With Icosapent Ethyl and a Mineral Oil Comparator on Interleukin-1β, Interleukin-6, C-Reactive Protein, Oxidized Low-Density Lipoprotein Cholesterol, Homocysteine, Lipoprotein(a), and Lipoprotein Associated Phospholipase A2: A REDUCE-IT Biomarker Substudy" and “Cerebral Microbleeds During Transcatheter Aortic Valve Replacement: A Prospective Magnetic Resonance Imaging Cohort” and the editorial "Trials and Tribulations of Randomized Clinical Trials." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center, and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: It's double feature time Greg. We've got two totally unique and interesting papers that we'll be discussing. The first, a biomarker substudy from the REDUCE-IT trial, that is looking at the effects of randomized treatment with icosapent ethyl, versus a mineral oil comparator, on inflammatory biomarkers. Now, don't use roll your eyes at me, because I'm telling you, this has results that you may not expect, and very, very important clinical implications, and implications for clinical trials. The second paper, very much up your alley, Greg, is a prospective MRI study of cerebral microbleeds during TAVR. But okay, enough now to whet your appetite, let's now just first grab coffees, and discuss the other papers and the issue, shall we? Dr. Greg Hundley: You bet, Carolyn. And how about if I go first? Dr. Carolyn Lam: Please. Dr. Greg Hundley: So, Carolyn, my first paper comes from a group of investigators led by Dr. Araz Rawshani from the Institute of Medicine, and it included 715,143 patients with diabetes, registered in the Swedish National Diabetes Register, and compared them with over two million match controls, randomly selected from the general population, to determine the role of diabetes in the development of valvular heart disease, and particularly, the relation with risk factor control. Dr. Carolyn Lam: Huh? Interesting, diabetes and valve disease. All right. What did they find, Greg? Dr. Greg Hundley: Right, Carolyn. So they found, that individuals with type one and two diabetes, have greater risk for stenotic lesions. Whereas, risk for valvular regurgitation was lower in type two diabetes. Patients with well controlled cardiovascular risk factors, continued to display higher risk for valvular stenosis, without a clear stepwise decrease in risk between various degrees of risk factor control. So Carolyn, diabetes and a link with valvular heart disease. Dr. Carolyn Lam: Wow. Really interesting, Greg. Thanks. Well, the next paper is a preclinical study with really interesting clinical implications. Now, we know the human heart has limited capacity to regenerate new cardiomyocytes, and that this capacity declines with age. Now, because loss of cardiomyocytes may contribute to heart failure, it is important to explore how stimulating endogenous cardiac regeneration, to favorably shift the balance between loss of cardiomyocytes and birth of new cardiomyocytes, occurs in the aged heart. Now, these authors, Doctors Rosenzweig, from Massachusetts General Hospital, and Dr. Lee from Harvard University and colleagues, previously showed that cardiomyogenesis can be activated by, guess what? Exercise in the young adult mouse heart. However, whether exercise also induces cardiomyogenesis in aged hearts, however, is not yet known. So in today's paper, the authors aim to investigate the effect of exercise on generation of new cardiomyocytes in the aged heart. And here, we're talking about 20 month old mice, who were subjected to an eight week voluntary running protocol, and age matched sedentary animals who served as controls. Dr. Greg Hundley: Wow, Carolyn. Really interesting evaluation of exercise on cardiomyogenesis. So what did they find? Dr. Carolyn Lam: Endogenous cardiomyogenesis can be stimulated by exercise in aged hearts. Comparative global transcriptional analysis further revealed, that exercise and age specific changes occurred in gene programs. The regulator of calcineurin RCAN1.4 was specifically found to be induced with exercise in aged hearts, and was accompanied by reduced calcineurin activity. So what's a take-home message? Exercise induced cardiomyogenesis may counter the increased cardiomyocyte loss and reduced cardio myogenic capacity in elderly patients. Dr. Greg Hundley: Great, Carolyn. Well from the mail bag, there's an exchange of letters to the editor from Professor Zhou and Veith regarding a prior letter to the editor from Professor Jin and associates, pertaining to the previously published article “SPARC, A Novel Regulator of Vascular Cell Function in Pulmonary Hypertension.” And also, there's a Perspective piece, from Professor Mentz entitled, “Catastrophic Disruptions in Clinical Trials.” Dr. Carolyn Lam: There's also a Research Letter by Dr. Kumar on [entitled] “von Willebrand Factor Is Produced Exclusively by Endothelium, Not Neointima, in Occlusive Vascular Lesions in Both Pulmonary Hypertension and Atherosclerosis.” There's also this beautiful tour of Cardiology News from the literature, from Tracy Hampton, which ranges from a study linking COVID-19 to higher long term cardiovascular risks, which was published in Nature Med, to uncovering alternative metabolic pathways involving cell fate transitions, published in Nature, to designing an autonomous biohybrid fish, from human stem cell derived cardiac muscle cells, that was published in Science. Wow. Isn't that amazing, Greg? Well, let's get on now though, to our two feature papers. Shall we? Dr. Greg Hundley: You bet. Welcome listeners, to these two feature discussions on this particular day. And our first feature today, we have with us Dr. Paul Ridker, from Brigham and Women's Hospital in Boston, Massachusetts. Dr. Bob Harrington, from Stanford University in California. And also, Dr. Allan Jaffe, from Rochester, Minnesota. Welcome to you all. And Paul, we're going to start for you. Can you describe for us, the background information that really went into the construct of your study, and what was the hypothesis that you wanted to address? Dr. Paul Ridker: Sure, Greg. So first of all, my thanks to the AHA and the Circulation for publishing this paper, we always want to support the AHA, and we're delighted to be here today for these podcasts. The field of omega-3 fatty acids has been a complicated one for a long time. Epidemiology suggested that, fish consumption would lower cardiovascular risk, and there was a number of trials done. And my friend and colleague here at the Brigham, Deepak Bhatt, was the lead of a very big trial, called REDUCE-IT. Some 8,000 plus patients who received EPA alone, and they got a terrific result. A 25% reduction in their primary endpoint. And this was a New England Journal paper, back in 2019 or so. But another friend of mine, Steve Nicholls, ran another large trial of a combination of eicosapentaenoic acid, or EPA, plus docosahexaenoic acid that's DHA called STRENGTH. And that one showed, really, no benefit. And so, there's been some controversy out there. In any event, when Deepak and his colleagues published their original paper, they said it's interesting, because they got this big risk reduction, but it wasn't apparently due to the triglyceride lowering of the drug. And so, my interest, as many people know, has largely been in inflammation biology. And so we said, well maybe we should just do a test. Well, we said, we'll measure a number of biomarkers that we know were associated with atherosclerosis, some inflammatory, some with coagulation. And so, that was the core hypothesis, was simply to look at some other markers, and see what we might learn. And sometimes, you learn things that you didn't expect. And I think, that goes to the heart of what complicated clinical trials are all about. And I'd also say perhaps, what the roles of surrogate endpoints are, as compared to hard clinical endpoints, and things that make this whole field kind of interesting. Dr. Greg Hundley: Right. Very nice, Paul. So you mentioned REDUCE-IT, so describe a little bit more for your study. What was the study population, and what was your study design? Dr. Paul Ridker: We were fortunate enough to work with REDUCE-IT investigators, to use their biobank. They had put together, again, it's 8,000 plus patients. I think, it was two thirds secondary prevention, one third primary prevention. And when they received the combination of EPA and DHA, as I said earlier, they had about a 25% reduction in the risk of their primary endpoint, which was cardiovascular death, nonfatal AMI, nonfatal stroke, coronary revascularization, and the like. What we did is, we basically said, "Okay, since the mechanism was uncertain, why don't we go ahead and measure a series of biomarkers?" Things that a lot of us are interested in, homocysteine, LPLa, oxidized LDL, my own interest in inflammation. We measured, IL-1β, we measured, IL-6, we measured CRP. We measured another molecule, Lp-PLA2, that people have been interested in. And the hypothesis, of course, was to see what the drug did, as compared to the comparator did. And the findings were interesting to us, in that, to simplify them, the actual icosapent ethyl arm didn't do much to most of those biomarkers, very little change. But the mineral oil comparator arm had some small to modest effects on all those biomarkers, all of which went up again. Now, some of these effects are pretty small, two to 3% for things homocystine, LPLa. Others were moderate, 10 to 20% increases in oxidized LDL, Lp-PLA2. And the inflammatory markers went up about 25%, sometimes, even a little more. So it's complicated. It's important to point out, that these changes on an absolute scale are relatively small. On a percent scale, they're different. The REDUCE-IT investigators themselves, to their credit, had earlier published that, they saw some increase in LDL cholesterol as well, about 10, 11% in those who had received the mineral oil comparator. So it's not exactly what we thought we were going to find, I guess, is the simplest way to express it. Dr. Greg Hundley: Very nice. And so, describe for us just a little bit more, any differences in men and women, and what about age? Or for example, premenopausal, postmenopausal women. Dr. Paul Ridker: No, the effects were quite consistent across all various subgroups. It's a very large study. There were, again, 8,000 patients, lots of blood samples been drawn. And I should again, commend the REDUCE-IT investigators, for allowing us to do this work with them. And again, as I point out, sometimes you find things out that weren't what you expected. And the hard part, I was glad this got tossed over with Dr. Harrington, is sort to figure out well, what's it really mean? Because again, as a clinical trial list, I will say, my instincts are to trust the primary endpoint of the trial. That's what they did. They're going to go out and lower heart attacks and strokes. And then, here we are a couple years later, trying to figure out what the mechanism might be, and just came across some puzzling results. Dr. Greg Hundley: Very nice. Well, next listeners, we're going to turn to the editor that actually processed this manuscript, Dr. Allan Jaffe. Allan, what drew you to this particular article? Dr. Allan Jaffe: Well, I was asked to be a guest editor this week, by the Journal, because of some conflicts that were intrinsic to the editorial board. And since I have an interest in biomarkers, and had for a long time, it made perfect sense for me to become involved. I was particularly interested in this particular area, because I was aware that there were these two trials that had found different endpoints, and that there were some controversy as to what the mechanisms might be by which these effects could occur. And so I was pleased to get involved. And I think it's a compliment to the REDUCE-IT investigators, and to Dr. Ridker, that they were willing to put the data out there so that everybody could see it. And we could then begin to look. So it was of interest to me. I thought it was important to the field, to get really good reviewers who would be, make sure that the data that would eventually be published was clear, so that readers would understand it. And so that, at the end, we'd be able to at least, come to some conclusions that we could end up having an expert in clinical trials. And I thought about Bob Harrington, right from the beginning, might be able to comment on. Dr. Greg Hundley: Very nice. Well, Bob he's setting you up here nicely, both Paul and Allan, to really help us put these results in perspective with other studies that have been performed in this space. What are your thoughts? Dr. Robert Harrington: So first off, Greg, thanks for having me. And Allan, thanks for inviting me to review and comment on the paper. As both Allan and Paul have indicated, that I've spent the last 30 plus years doing clinical trials of all sizes. Very small, where we try to understand mechanisms, and very large, where what we're trying to understand is clinical outcomes. And I've been intrigued in this field, because of the inconsistency of the data across the field. Where in some trials, Paul had indicated this STRENGTH, there seemed to be no effect of omega-3 fatty acids, and in REDUCE-IT, there was quite a pronounced effect of the test agent. And so, when one sees discordance in a field, one tries to understand, well, why might that be? And so in the editorial, I took the position that, well, what are we trying to do in clinical trials? And in outcomes trials, we're trying to figure out what matters to patients. Do they live longer? Do they feel better? Do they avoid bad stuff happening to them? Like having to undergo revascularization procedure. So you're trying to do things that are really clinically meaningful, but that doesn't say that you're also not trying to understand mechanism. And as Allan said, there have been some questions raised. And so, trying to understand mechanism in the edit in trials can be quite useful, not just to understand that trial results, but to really form hypothesis for a field going forward. And so, I took the approach of, we learn things from different trials, and sometimes we learn things in the same trial. Meaning that, there's mechanistic work embedded in the large trial. One of the most famous examples of this, in the GUSTO trial 30 years ago, we learned through the mechanistic substudy, that it was rapid reprofusion TIMI-3 establishment of TIMI-3 flow, that really explained the difference between TPA and streptokinase. So I was very intrigued by how we might use these data to explore the results. And I find the findings fascinating, as Paul said. It is complicated, but it raises a really fundamental issue in clinical trials. There's an assumption in a placebo control trial, that because randomization is allowing you to balance everything, except for the randomized treatment groups, and therefore, that comparison has causal information in it. There's an underlying assumption that's really important. And that is, that the placebo is inert. That it has no biological effect of its own. Well, that assumption was violated here. The placebo is not inert in this clinical trial. Now, the investigators, I think to their credit, have said, "Well, this is small, probably doesn't matter." And that might be right, but it also may be wrong. And you can't just say, well, it doesn't matter, these are small effects. As Paul said, some of the effects are small, some are medium, some are large. So what explains it? And I made a point in the editorial, you could model all of this. If you get 5% of this, and 10% of this, and 20% of this, you could make some assumptions and say, well, the magnitude of the benefit was so great that it couldn't have been overcome by this. But that's just modeling, and there's uncertainty. So for me, as a trialist, and somebody who really believes in using evidence to guide practice and to guide public policy, I think there's uncertainty here. It's likely that the treatment effect is not as large as was observed, but how large is it? And how large is important? And how large might we want to consider to put into our practice guidelines? I think all of those open questions, particularly in a field where there is inconsistency across trials, in terms of the observation of the outcome. So my conclusion is, we need more work. We need another trial, if we really want to understand this. And we need to use an inert placebo, to really understand what the contribution was. I'd like nothing better to see that it didn't matter. But I can't say that it doesn't matter because I don't know. Dr. Greg Hundley: Well, listeners, boy, we've got kind of some interest here in that an unexpected result. So Paul, it's nice doing an interview like this listeners, because each speaker sets up the next one. Paul, Bob is saying, well, what should we do next to clarify the results here? So maybe we'll go through each of you, and start with Paul. Just describe for us, what do you think is the next study that we need to perform? Dr. Paul Ridker: Well, Greg, it's a really interesting issue. We saw it, as authors, to write as neutral a paper as we could possibly write, and sort of do our academic job and say, here are the data. And I think we did it that way because, we don't really know what the interpretation should be. On the one hand, you have a very big beneficial result, which is great for patients. And there's a prior clinical trial called JELIS, which was open label, the same drug, and also got a large benefit. And we were trying to figure out mechanism. That being said, as Bob pointed out, I think what we stumbled into is some level of uncertainty. And the question is, how uncertain would it be, and does it matter in the big picture? Allan was interesting, because the Journal asked us to use the word comparator, rather than placebo. Now this was designed as a placebo controlled trial, but our paper uses the word comparator, because of the possibility, that as Bob Harrington points out, it may not be totally inert. So the writing of this was quite carefully done. I think, at the end of the day, my REDUCE-IT colleagues, who I have great respect for, and really worked terribly hard to do the main trial, understandably feel, that the trial would've showed, and I have a lot of sympathy for that, because it's the hard endpoints we should go with. On the other hand, I have sympathy with the idea that it never hurts to have more data. And if there could be a way to have a second trial, and I might change the population a little bit, maybe I'd do it in true primary prevention. This was one third primary prevention. My colleague, Joanne Manson had done her, she had a trial where they showed some potential benefit in the black populations. Maybe you might over sample some minority groups. But just the pragmatic issues here, make it tough to have a second trial. And so, uncertainty is just part of what we, as physicians, have to learn to live with. Dr. Greg Hundley: Allan, turning to you. What do you think is a next study to perform in this space? Dr. Allan Jaffe: Well, I think what Paul has said is correct. That it would be very hard to generate enthusiasm funding for a large trial. But it might not be nearly as difficult to begin to explore the effects of the mineral oil comparator, versus the active agent, versus perhaps, another potential placebo, and see over time what happens in primary prevention patients, as a way of beginning to put some context around what these results might mean. So for example, it could turn out that, the active agent actually kept the values from rising as they normally would've, and mineral oil had no effect at all. Alternatively, mineral oil may well have been a negative. It had a negative effect. And I think, those are the sorts of questions that could be explored reasonably in the short term, without doing another multimillion dollar randomized trial. Dr. Greg Hundley: And Bob, your thoughts. Dr. Robert Harrington: Well, and I mentioned this in the editorial, Greg. I didn't make my recommendation lightly. I know that these trials are expensive. I know these trials take a great deal of time, a great deal of energy. And I know that the REDUCE-IT investigators worked enormously hard over the years to get this done. So I don't say tritely, "Oh, just do another trial." But if you think about the magnitude of the public health issue here, there are millions of people to who this kind of therapy might apply globally. And so, shouldn't we be more certain than less certain, if we want to include it, for example, in ACC/AHA guidelines? I would say, the answer to that is yes. And so, I think of it as, okay, let's make some assumptions. Let's assume, that the effect that was observed in JELIS and REDUCE-IT, is the true effect. That's ground truth. Well, there are different study designs one might think about, from an analytic perspective, using Bayesian statistics, as opposed to frequency statistics. One might think about an intense interim analysis plan, to understand where the data are going, and be able to pull in the prior data for evaluation. I would advise getting a smart group of people together, who spend their lives thinking about trials in the atherosclerotic space, and the REDUCE-IT team is pretty darn good, and say, "How could we do this efficiently?" I do think, there's enough uncertainty that it would be ethical, from an equipoise perspective, to include high risk patients in a second evaluation, because we do have uncertainty. And if we really want to nail this down, I think we could look at high risk patients with hypertriglyceridemia, and try to use some interesting design issues, and some interesting analytical issues, to try to reduce the sample size, lot of attention in interim analyses, to try to answer the question. I'd like, as I said, nothing better to say, "Oh look, REDUCE-IT was the truth." This next trial is consistent. That'd be, to me, a terrific outcome of this. On the other hand, if you said to me, "Well, the effect's not 25%, it's more in the 15% range." Well, maybe then we think about how we apply it to our patients a little differently, maybe a little more cautiously. So I don't make the recommendation lightly, as I said, but I do think that there are some conversations that could be had, being respectful of the effort and the expense that goes into these kind of things. To try to answer the question efficiently. Dr. Greg Hundley: Very nice. Well listeners, we want thank Dr. Paul Ridker, from Brigham and Women's Hospital, Dr. Bob Harrington from Stanford University, Dr. Allan Jaffe, from the Mayo Clinic, for bringing us the results of a substudy of the REDUCE-IT trial, that assessed a variety of serum biomarkers, pertaining to systemic inflammation, and highlighting uncertainty around the mechanism regarding the efficacy of icosapent ethyl, that's been used previously for primary or secondary prevention of cardiovascular events. And next listeners, we are going to move to our second feature discussion and review some data pertaining to microbleeds in the central nervous system, during and after TAVR procedures. Welcome listeners, to our second feature discussion on this August 2nd. And we are going to explore some of the world of TAVR and its potential complications. And we have with us today, Dr. Eric Van Belle, from Lille, France. And also, Dr. Manos Brilakis, from Minneapolis, Minnesota. Welcome gentlemen. And Eric, we'll start with you. Can you describe for us a little, the background information that you use to assemble and construct your study, and describe, or list for us, the hypothesis that you wanted to address? Dr. Eric Van Belle: Yes. Thanks a lot for the question. So we knew for many years, that some of the complication of the TAVR procedure relate to the brain. And it has been described by many others, that there were some complication in the brain of patient undergoing TAVR. And there was no previous investigation on potential bleeding or microbleeding in this population. And on the other side, there are previous publication on, of course, initially chronic microbleeding, in patient with some of, let's say, disease in the brain, but also, a possibility of acute microbleeding. And especially, in some interesting population relating to the TAVR feed, that is patient with valve disease, patient with endocarditis, or patient with assist device. In this population, microbleedings, acute microbleeding, have been described. And what is interesting, if you look at all these populations, these are population in which the Von Willebrand factor has been impacted and modified, and could be one of the reason of the microbleeding. And one of the similar feature of the patient with aortic stenosis that undergo TAVI, or TAVR, that are patient with indeed also, this kind of Von Willebrand disease. So if we put everything together that is previously, we only looked at antibody complication in those population, and that Von Willebrand disease, which is present in patient with aortic valve stenosis, could promote a bleeding, in particular, bleeding in the brain. We decided to look at the potential appearance of microbleeding, in patient undergoing TAVR procedure. Dr. Greg Hundley: Very nice. And Eric, can you describe for us, your study design, and who was your study population? Dr. Eric Van Belle: Yes. So basically, the study population is a basic population of patient undergoing TAVI. Just to make sure that one of the difficulty of this study, was to conduct and perform an MRI, a brain MRI, before the procedure, and as short as possible after the procedure, within three days, which is logistically challenging. And also, to make sure that we keep most of the population to undergo the MRI, we had to exclude patient with a high risk of pacemaker, or patient with pacemaker that could not undergo the MRI. But basically, without this, it's just a regular population. And if we indeed, compare to some of the previous work I was mentioning, about describing the acute MRI, it was important for us to make sure, or to be as sure as we could get, that indeed, this microbleeding, if we observe them, could be related to the procedure. And it means that, the MRI, after the procedure, should be done as short as possible. And also, that an MRI, a baseline MRI, should be performed. Because we know, that in this population, you could have some microbleedings also observed before starting the procedure. Dr. Greg Hundley: So a cohort study design where MRIs are performed before, and then very soon after, TAVR procedures. So Eric, what did you find? Dr. Eric Van Belle: So what we observed, the first thing that we confirmed was indeed, that in this population of that age, that is patient around 80 years old, when we do the baseline MRI, you find in about one out of four patients already, some microbleedings. And this was expected, and it is very similar to what is expected in this kind of population. But what was indeed more striking, that when we repeated the MRI after three days, we observed another 23% of patient with a new microbleedings that were observed. This is indeed the most important observation. What was also important that, the patient with microbleedings, and the location of the microbleedings, were not related to the cerebellum brain, because indeed we could observe some cerebellum arise in this population, as it is expected. And there was no relation between the two. So it's also, an important observation, suggesting that this microbleeding are not hemorrhagic transformation of cerebellum brain, for instance. And we also observed that, the risk of microbleeding, or the chance to observe the microbleeding, was increased when the procedure was longer. And also, when the total duration of anticoagulation was longer, we also observed that, when the procedure was, when we used protamine at the end of the procedure, the risk of microbleeding was less. And also, importantly, the status of the Von Willebrand factor, and indeed, an alteration of the multimer of Von Willebrand factor, was also associated with the risk of microbleeding in this population. Dr. Greg Hundley: Very nice. So in this cohort of 84 individuals, average age around 80, undergoing TAVR procedure, and about 50/50 men and women, you had several factors. Prior history of bleeding, amount of heparin, absence of protamine, all indicating a higher risk of these microbleeds. So very practical information. Well, Manos, you have many papers come across your desk. What attracted you to this particular paper? And then secondly, how do we put these results really, in the context of maybe other complications that can occur during or after TAVR procedures? Dr. Emmanouil Brilakis: Yes, thanks so much, Greg. And also, congratulations Eric, for a wonderful paper, and thanks for sending it to circulation. I think, with increasing the number of targets, as you know, TAVR now is becoming the dominant mode for treating severe aortic stenosis. Safety is of paramount importance. And even though there's been a lot of progress, we still have issues with the safety of the procedure. So understanding how can make it safer is very important. And I think, what was unique in this paper, again, congratulations for creating this study, is that it opens a new frontier. We worry about stroke. We're all very worried about the stroke, and having the patient have a permanent neurologic damage during the procedure. But there may be more to it than the classic embolic stroke. And I think, this study opens actually, a new frontier with the micro cerebral bleeds. Now we don't completely understand, despite the study, we don't understand the functional significance from this. And I think, that's one of the areas that will need further research. But I think, trying to understand what causes them, and preventing those microbleeds, would have a very important role in the future, for making TAVR even safer than it is. Dr. Greg Hundley: Very nice. Well, Manos, you really lead us into the kind of the next question. So Eric, what do you see as the next study to be performed in this sphere of research? Dr. Eric Van Belle: Again, to me, and to follow with the comment of Manos, we need to include, I would say, to solve two questions. We have to solve the question of, what could really impact these microbleedings. And what would be the impact of this microbleeding on the long term outcome of this patient? So it's means that we have to set, as part of the studies that we will design, potentially studies on aortic immolation. Or let's say for instance, we could investigate the role of protamine. It has been suggested that protamine could be something interesting, so it could be tested as part of a randomized study. But this means that, as part of such randomized study on the use of protamine, for instance, you would include a last cohort of patients with MRI after the procedure. And also, a long term follow of the neurological complication, which indeed, is the missing part of our current study. We would need to have a much larger cohort of patients, to be able to reconnect the neurological outcome to the MRI outcome, and also to include this. So let's say, for me, one of the studies we would be interested to perform, is to conduct a study on the use of protamine, which is very simple, randomized, yes or no, and includes brain MRI in this population, as a systematic investigation, which is difficult to conduct. You have to know that it's difficult to do, but it will be very important. And then, to look at the long term neurological outcome. Dr. Greg Hundley: And I see, Eric, you mentioned the long term, because really in the short term, so within six months, you really didn't see any changes in neurological functional outcome or quality of life. So Manos, just coming back to you. What do you see is the next study that should be performed in this space? Dr. Emmanouil Brilakis: Yeah, I agree actually, with Eric. The next step is, this was an 80 patient study. Right? It's a very small preliminary data, all that opens a new system for evaluation, we're still a very small number of patients. So having a larger number of patients, I think for me, the key thing is to understand the connection. Does this actually cause neurologic symptoms? What does it mean having a microbleed? I think right now, we're still confused on the study. There was not really much impact on the neurologic status of the patient. So for me, the number one thing is, to understand how it impacts the patient's quality of life, the neurologic status. Perhaps more sensitive studies, neurocognitive studies, to understand exactly how it impacts. And then after doing that, I agree with Eric, if this is a bad, something really bad, then we can find different ways to prevent them from happening. Protamine is one of them during the procedure time, and not be a very feasible one. Or it could be interesting to see if different valves, for example, have different propensity for causing those microbleeds. Dr. Greg Hundley: Very nice. Well listeners, we want to thank Dr. Eric Van Belle, from Lille, France, and also, our own associate editor, Dr. Manos Brilakis, from Minneapolis, Minnesota for bringing this very important study, highlighting that one out of four patients undergoing TAVR has cerebral microbleeds before the procedure. And then, after the procedure, one in four patients develop new cerebral microbleeds. And then, procedural and antithrombotic management, and persistence of acquired Von Willebrand factor defects, were associated with the occurrence of these new cerebral microbleeds. Well, on behalf of Carolyn and myself, we want to wish you a great week, and we will catch you next week On the Run. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors, or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join authors Mikhail Kosiborod and Christian Schulze and Editorialist Stefan Anker as they discuss the original articles "Effects of Empagliflozin on Symptoms, Physical Limitations and Quality of Life in Patients Hospitalized for Acute Heart Failure: Results From the EMPULSE Trial" and "Effects of Early Empagliflozin Initiation on Diuresis and Kidney Function in Patients With Acute Decompensated Heart Failure (EMPAG-HF)" and the editorial "SGLT2 Inhibitors: From Antihyperglycemic Agents to All-Around Heart Failure Therapy." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor, director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: I'm so excited about the feature discussion this week. It is a paired feature along with their editorial and it's all focused on SGLT2 inhibitors. The first, results from the EMPULSE trial, Effects of Empagliflozin on Symptoms, Physical Limitations and Quality of Life in Patients Hospitalized for Acute Heart Failure; and the second, the EMPAG-heart failure trial, The Effects of Early Empagliflozin Initiation on Diuresis and Kidney Function in Patients with Acute Heart Failure. Incredibly important topics, incredibly important discussion. Wait up for it. We're just going to tell you a little bit more about two other original papers in today's issue, and I'm going to go first, Greg. Is that okay? Dr. Greg Hundley: You bet. Dr. Carolyn Lam: Now, really interesting topic here. We have strong evidence supporting the effective blood pressure and cardiovascular disease risk lowering properties of healthy diet such as the DASH diet, Mediterranean diet, and so on and so on. But what about the diet consumed by a fifth of the entire world's population? The Chinese cuisine. Interestingly, today's paper addresses just that. This is from authors, Dr. Wu, from Peking University Clinical Research Institute and colleagues who performed a multicenter patient and outcome assessor blind randomized feeding trial among 265 participants with baseline systolic blood pressure of 130 to 159 in four major Chinese cuisines. And these are the Shandong, Huaiyang, Cantonese, and Szechuan cuisines, and here's how they did it. After a seven day run in period on a control diet matching the usual local diets, participants were randomized to continue with the control diet or the cuisine based Chinese heart healthy diet for another 28 days. The primary outcome was systolic blood pressure. The study developed the first heart healthy Chinese diet that fits Chinese food culture and emphasizes its palatability by involving master shifts in developing the recipes. Dr. Greg Hundley: Oh wow. Carolyn, this is really interesting, especially one fifth of the world's population in studying a heart healthy diet. So did it work? I can't wait to hear the results. Dr. Carolyn Lam: Well, the change in systolic and diastolic blood pressure from baseline to the end of the study in the control group was five millimeters mercury and 2.8 millimeters mercury reduction, respectively. The net difference of change between the two groups in systolic and diastolic blood pressure were a reduction of 10 and almost four millimeters mercury, respectively. The effect size did not differ among cuisines, and so in summary, with a patient and assessor blind randomized feeding trial, this study really demonstrated that the blood pressure lowering effect of the Chinese heart health diet could indeed be substantial, and importantly, be compatible with medications while palatable and affordable in Chinese adults with high blood pressure, and so these results support the idea that food is medicine and will give many patients with high blood pressure the confidence to adopt heart healthy diets in their lifestyle treatment. Dr. Greg Hundley: Wow, Carolyn, that is really an interesting article. So many of these articles today could all be features in and of themselves. That was just outstanding. Well, my next paper comes to us from the world of preclinical science, and it's from Dr. Sean Wu from Stanford University School of Medicine. So Carolyn, immune checkpoint inhibitors are monoclonal antibodies that are used to activate the immune system against tumor cells. Now, despite their therapeutic benefits, immune checkpoint inhibitors have the potential to cause immune mediated adverse events such as myocarditis, a rare but serious side effect with up to 50% mortality in affected patients. Now histologically, patients with immune checkpoint inhibitor of myocarditis have lymphocytic infiltrates in the heart implicating T-cell mediated mechanisms. However, the precise pathologic immune subsets and molecular changes in immune checkpoint inhibitor myocarditis are unknown. Dr. Carolyn Lam: Wow. So insights into the etiology of these immune checkpoint associated myocarditis cases must be very important. So what did they find? Dr. Greg Hundley: Right, Carolyn? So clonal cytotoxic, TEMRA CD8+ cells were found to be significantly increased in the blood of patients with immune checkpoint inhibitor myocarditis corresponding with an analogous increase in effector cytotoxic CD8+ cells in the blood and hearts of PD-1 deficient mice with myocarditis. These expanded effector CD8+ cells had unique transcriptional changes, including upregulation of the chemokines CCL5, CCL4, and CCL4L2, and they may serve as attractive diagnostic therapeutic targets for reducing life threatening cardiac immune related adverse events in immune checkpoint inhibitor treated cancer patients, and Carolyn, just like so many of our articles, there's a very nice accompanying editorial by Professor Gianluigi Condorelli that also offers an update on current research pertaining to non-systemic steroid therapy to treat immune mediated myocarditis. Well, Carolyn, how about we jump to some of the other articles in the issue? Dr. Carolyn Lam: Oh, you bet, Greg. There's an exchange of letters between Drs. Madias and Knops regarding the article “Efficacy and Safety of Appropriate Shocks and Antitachycardia Pacing in Transvenous and Subcutaneous Implantable Defibrillators: The Analysis of All Appropriate Therapy in the PRAETORIAN Trial.” Dr. Greg Hundley: And also in the mail bag, Professor Mark has a Research Letter entitled “Effect of Empagliflozin on Kidney Biochemical and Imaging Outcomes in Patients with Type 2 Diabetes, or Prediabetes, and Heart Failure with Reduced Ejection Fraction, The SUGAR-DM-HF Study,” and our own Tracy Hampton has several synopses from articles published elsewhere in our piece on cardiovascular news. Well, how about we get onto that feature forum discussion, two papers, two editorialists. I can't wait. Dr. Carolyn Lam: Me too. Let's go, Greg. Dr. Greg Hundley: Welcome, listeners to this July 26th feature forum discussion. So remember, listeners, for forum discussions, we have several manuscripts that focus on a singular topic and we bring together the authors, our associate editors, and also an editorialist, and today, I want to introduce, we have with us Dr. Mikhail Kosiborod from Mid America Heart Institute in Kansas City, Missouri, Dr. Christian Shults from University Hospital Jena in Germany, Stefan Anker from Charité in Berlin, Germany, and our Associate Editors, Brendan Everett from Brigham and Women's Hospital in Boston, Massachusetts, and Justin Grodin from University of Texas Southwestern Medical Center in Dallas, Texas. Welcome, gentleman, and we'll start with you, Mikhail. Could you describe for us the background information that went into the preparation of your study and what was the hypothesis that you wanted to address? Dr. Mikhail Kosiborod: Well, thanks very much, Greg. The background for the study, which was the secondary analysis of the EMPULSE trial was patients that are hospitalized with acute decompensated heart failure represent a very high risk group. We know that they have high risk of death and hospitalizations, and we also know that they have very poor health status that's very high burden of symptoms, physical limitations, and poor quality of life, and so addressing those treatment goals, trying to reduce the risk of clinical events like death and hospitalizations and improve the symptoms and physical limitations in this patient population are very important treatment goals. Now we previously demonstrated in the main results of the EMPULSE trials that using empagliflozin initiating empagliflozin SGLT2 inhibitor in this patient population as compared with placebo provided a significant total clinical benefit, which was a composite of total death, repeat hospitalizations for heart failure, or a change in a Kansas City cardiomyopathy questionnaire, which is a kind of a gold standard measure of patient's health status. What we tried to do in a much more granular fashion in this study is to understand the effects of empagliflozin as compared with placebo on this very important outcome, the Kansas City cardiomyopathy questionnaire, and we actually evaluate all of the key domains and composite symptoms, physical limitations, as well as quality of life. Dr. Greg Hundley: Very nice, and Mikhail, can you describe for us what study population specifically, and then what was your study design? Dr. Mikhail Kosiborod: Well, this was a population of patients that were hospitalized with heart failure and that EMPULSE was unique in its design because first of all, previous SGLT2 inhibitor trials mostly focused on patients with chronic heart failures that were in an outpatient setting, including prior trials of empagliflozin, and EMPULSE really focused on acutely hospitalized patient population, but it included patients regardless of ejection fraction. So as they were hospitalized with decompensated heart failure and reduced or preserved ejection fraction. They were enrolled regardless of if they had type 2 diabetes, they were enrolled essentially, regardless of kidney function, only patients with EGFR of less than 20 were excluded, and also importantly, was this study and a unique feature of the study in particular was that we enrolled patients whether they had acute de novo heart failure. That means that was a new diagnosis of heart failure that was bad enough for them to be hospitalized or worsening chronic heart failure requiring hospitalization. So it was really an all-comer trial for patients acutely hospitalized for heart failure. So we had just over 500 patients and they were randomized in the hospital. After a brief period of stabilization, we use empagliflozin, 10 milligrams daily or placebo and treated for 90 days, and the primary outcome at 90 days was a total clinical benefit that I described that was a composite, hierarchical composite of total death hospitalizations, repeat hospitalizations for heart failure and changing KCCQ. In this study, again, we focused predominantly on KCCQ, trying to understand the effects on health status, again, symptoms, physical limitations, and quality of life. Dr. Greg Hundley: Excellent. And Mikhail, what were your study results? Dr. Mikhail Kosiborod: Well, what we observed, a couple of things. One is we first examined the effects of empagliflozin on the primary endpoint across the range of KCCQ and baseline, and what we found was that regardless of the degree of symptomatic impairment and baseline, empagliflozin was consistent in providing them total clinical benefits that I described previously, and then kind of shifting to what I think is the most interesting findings, the effects of empagliflozin versus placebo on KCCQ, what we found was that as you would imagine in this population of patients that were acutely hospitalized with heart failures, that had very poor health status, very low KCCQ at baseline, and within the first 90 days, which was observation period, both groups of patients had substantial improvements in KCCQs. As one would expect after acutely decompensated episode of heart failure and treatment in a hospital, everyone got better. But patients treated with empagliflozin had significantly greater improvement in KCCQs than those that were treated with placebo, and that was first of all, a very substantial difference between the two groups. It was more than five points in favor of empagliflozin already at 15 days and was highly statistically significant, and it was maintained throughout the 90 day treatment period. So the fact that we saw both a clinical meaningful and statistically significant improvement in just 15 days, I think is a very important clinical message, and then finally, I guess what I will mention is these benefits of empagliflozin while main outcome we looked at was KCCQ total symptoms, we're focusing on the symptoms, but it was consistent when we looked at physical limitations as well as quality of life. So really, all key domains of KCCQ were impacted in a similar way. Dr. Greg Hundley: Very nice. So in acute heart failure, marked symptomatic improvement after the administration of the SGLT2 inhibitor empagliflozin at 10 milligrams per day. Well, now listeners, we're going to turn to our associate editor, Dr. Brendan Everett, and Brendan, again, you have many papers come across your desk. What attracted you to this particular manuscript? Dr. Brendan Everett: Well, thanks, Greg, and I think this manuscript caught my eye because of the importance of the clinical question, and Mikhail outlined why I think that was really relevant. So we understand that this class of medications or SGLT2 inhibitors have important effects on outcomes like re-hospitalization in patients with heart failure, and what was particularly striking about this paper is that it took patients rather than those with chronic heart failure, but as Mikhail mentioned, enrolled a patient population that was actually in the hospital, and I think this was an important frontier for this particular question about when to start the SGLT2 inhibitor and what kind of benefits there might be. Furthermore, I think the fact that they did not select the population based on ejection fraction was particularly striking, and of course, I think is remarkable, but now old news, they did not select on the presence or absence of diabetes as well. And so those three components really attracted me to the paper. I also think the outcome is one that really is valuable and worth exploring, and specifically, I'm talking about how patients feel on the medication after a hospitalization for heart failure. Appropriately, we focused on re-hospitalization for heart failure and cardiovascular death in prior trials in this space, and I think we need to embellish those findings or further deepen those findings with a perspective on how patients actually feel when they get the medication, and of course, it goes without saying that what's particularly important here also is that it was a randomized placebo controlled trial, and so the results have some element of internal validity that I think is really important. So those were the things, Greg, that really attracted my attention as I read the paper for the first time. Dr. Greg Hundley: Thank you so much, Brendan. Well, listeners, we've got a second paper today and we're next going to hear from Dr. Christian Shults, and he also is focusing on really another aspect of the administration of empagliflozin in patients with acute heart failure and that pertains to the renal function of the patients. So Christian, could you describe for us the background pertaining to your study and what was the hypothesis that you were intending to address? Dr. Christian Schulze: Thanks, Greg. Well, it's great to introduce all study here in this running. So our study impacted those in acute decompensated heart failure. The impact HF trial was a study based on the hypothesis that we wanted to test, whether empagliflozin has effects in acute decompensated heart failure, and we focused on the patient population that was not addressed in EMPULSE, patients that came to the ER and needed to be treated right away, and we wanted to know and this was our main hypothesis, but are the diuretic and [inaudible 00:17:11] effects of the SGLT2 inhibitor on this case, empagliflozin, actually had an impact on diuretic regimens and kidney functions since this is one of the main end points that limits treatment, and also is one of the outcomes of patients with acute decompensated heart failure in the hospital. Dr. Greg Hundley: Very nice. And so Christian, what study design did you implement and who was included in your study population? Dr. Christian Schulze: So we also used the randomized two arm study design. We included patients with acute decompensated heart failure independent of left ventricular ejection fraction. Patients needed to have an NT-proBNP of more than 500. The average NT-proBNP in fact was 4,300 in our entire patient population, and we included patients within 12 hours of presentation. So many of these patients have been recruited in the ER, they presented two hour cardiology heart failure service, and then were immediately randomized to the trial in the two arms, and we tested not 10 milligrams of empagliflozin. We actually tested 25 milligrams of empagliflozin based on in-house data that 25 milligrams potentially had a stronger diuretic effect compared to 10 milligrams. Dr. Greg Hundley: And what did you find? Dr. Christian Schulze: So we followed patients for five days. It was a relatively short period of time. It was designed to address the in-house phase of patients with acute decompensated heart failure. The mean duration of stay was 6.3 days in the hospital so this was exactly the time that we wanted to test. We had a 30 day endpoint for safety issues, and what we could see is that patients on 25 milligrams on empagliflozin on top of standard diuretic regimens and medical care had 25% higher diuretic outputs compared to patients in the placebo group. We also found no differences in markers of renal injury dysfunction, and could in fact confirm that after 30 days, patients in the empagliflozin group had a better EGFR compared to patients in the placebo group. On top, we saw a more rapid decrease in body weight and also a more profound decrease in NT-proBNT values. Dr. Greg Hundley: And Christian, just for our listeners to put a little bit of this in perspective, what was the range of serum creatinine for the patients that were enrolled in your study? Dr. Christian Schulze: So the main EGFR in the entire population was around 60 and the creatinine values were around 107 on average in the entire cohort. So this is a very typical population. We had around 30% of the population with de Novo heart failure, around 20 to 30% of the population was pre-treated for preexisting heart failure. So very typical population of patients with heart failure presenting to the emergency room. Dr. Greg Hundley: And did you have any kind of lower level EGFR cutoff, I mean, for enrollment into this study? Dr. Christian Schulze: So when we designed the trial, we actually still had the sub classification of diabetes or impaired glucose or homeostasis as an inclusion criteria. We dropped it before we started the trial because the data came out that this is actually, in fact, not a critical issue for patients with heart failure. So diabetes was not a subgroup in our trial and the lower limit of EGFR was actually a thoroughly defined protocol. Dr. Greg Hundley: Very nice. Well, listeners, now we're going to turn to our second associate editor, Dr. Justin Grodin from University of Texas Southwestern Medical Center in Dallas, Texas, and Justin, similar to Brendan, and you see many papers come across your desk and so what attracted you to this particular paper by Christian and his colleagues? Dr. Justin Grodin: Well, Greg, I think first and foremost, and I think very similar to Brendan, but I think what's always striking is if I may just take a step back, decompensated heart failure in the United States is the number one cause for hospitalization among Medicare beneficiaries. So I think really, the brunt and really the truly public health message of the disease is very important in the applicability, and even though that decompensated heart failures is one of the most common things that we ever encounter when we practice, internists, cardiologists, et cetera, we have very, very little clinical trial guidance that tells us how to decongest individuals when they're hospitalized with swelling and heart failure and a lot of these individuals can be quite ill, and we have some clinical trial data, but largely, we have a lot of negative studies or inconclusive studies in this space. So certainly, what drew me to this trial was definitely that context, and obviously, based on the mechanistic data with SGLT2 inhibitors, I think one of the natural questions, which Christian addresses, is that we know that up front, they do augment natriuresis. So I think it's very compelling to marry those two together because this is what many of us that use these medications regularly have been asking is whether or not they would have some efficacy in that regard, and then another thing that caught my eye and me as a cardiorenal investigator was, just as Christian highlighted, was we have a clinical trial that randomly assigned individuals, really that were ill and many of whom were not stabilized within 12 hours of presentation, and we're talking about patients that are coming into the hospital at all times during the day in and I think that's very remarkable that we have something with standard... We have a study with standardized assessments where we're really trying to ask a very practical, pragmatic question, which is do these therapies lower the sodium balance in individuals with decompensated heart failure, and I think what's important is largely, we've got a lot of medications that supplement loop diuretics, which are the class of drugs that the majority of us use, and we have a lot of other therapies that we use that really have very little data or poor data that guide us such as thiazide diuretics, carbonic and hydrase inhibitors, mineralocorticoid receptor antagonists, and so here, we have a clinical trial that asks a question that's on many people's minds. And then we do have very compelling, at least short term pragmatic and mechanistic data that does tell us that these individuals do have a greater natriuretic effect when empagliflozin is used as an adjunct to standardized loop diuretic therapy. So it's a very practical clinical question, and I think what's very important, and we could debate probably all day about the implications of GFR change and kidney function change while we're decongesting somebody with diuretics, but I think what's reassuring to all the clinicians is we really didn't see an effect on kidney function despite a greater natriuretic effect or enhanced diuretic effect, if you will, with the use of empagliflozin. Dr. Greg Hundley: Very nice. Well, thank you, Justin. Listeners, now we have an editorialist and as you know, editorialists really help us put the scientific presentation of an original manuscript into the perspective of really the global theme of a topic, and we have Stefan Anker from Berlin, and Stefan, can you describe for us how do we put these two manuscripts and results that we've heard about really in the context now of moving forward with the use of SGLT2 inhibitors in the management of patients with acute decompensated heart failure? Dr. Stefan Anker: Thank you so much. Really, I think these two papers, on the one hand, enhance our certainty about early use, and on the other hand, possibly show us that there might be even more to achieve by, on the one hand, moving even earlier with the application of SGLT2 inhibitors or possibly consider the higher dose. Now let's take one step back. These drugs were developed in type two diabetes and the first successful trial was the [inaudible 00:25:42] outcome trial. Many people have forgotten that this trial tested two doses and not only one, the 10 and the 25 milligram dose, and of course, with the success for improving kidney outcomes and heart failure hospitalization outcomes, we move forward into these two specialist areas, on the one hand, broadening it to the non-diabetic communities, but on the other end, narrowing it by focusing on the 10 milligram dose regardless of whether there is [inaudible 00:26:12]. And we basically now learn A, to use these drugs even earlier than we did in the big trials and we can now be sure to start their use in the hospital, and if you take the average change in quality of life results seen, you actually get a better result for the patient on quality of life when you start earlier than when you start late in the ambulatory studies where basically, in the chronic setting, maybe you have one and a half to two points difference. Here, you now have four and a half points in the study shown by Mikhail, and of course, it's also good to know that you can start this in any type of patient, regardless of their quality of life. The impact study from Christian, they basically moved it now even earlier, moving into the hospital space is possible based on EMPULSE. Moving it into the acute admission space is at least a consideration now based on what Christian here has shown. And he is actually addressing the one question I hear very often in my presentations about SGLT2 inhibitors, what about this 25 milligram dose? Is there a place for this in cardiology as well, and a possible place is shown here, not only that this is a safe thing to do, but also you get urinary output. Of course, we may in the future, want to see this compared, directly compared to the 10 milligram dose, but of course, the world is not created in one day, but needs more than one and so really, I think these two studies, on the one hand, address an important issue, when to start using them. On the other hand, show us a little bit of a glimpse to the future. Dr. Greg Hundley: Very nice, Stefan, and listeners, we get to take advantage of having these authors, editors, and editorialists together and ask them what they see as the next study to be performed in this sort of sphere of research. So Mikhail, we'll start with you. In 30 seconds or less, what do you see as the next study to be performed in this arena of research? Dr. Mikhail Kosiborod: I think, Greg, what we've learned recently, including from the EMPULSE trial, we have this population of patients in a hospital with heart failure's a huge issue as Justin mentioned, and until recently, we had very little [inaudible 00:28:31] for them beyond the usual kind of decongestion with loop diuretics and trying to make them feel better, but you look at outcome data. It really was a dearth of effective therapies that have meaningful impact on important outcomes. Now that's changing, SGLT2 inhibitors is one example. There are some other recent examples in this patient population, like a firm HF and iron deficient patients with heart failure. But the bottom line is it's no longer kind of a desert, if you will, of positive trials. We now have something we can do and I think what this proves is that we need to actually invest more, both in terms of resources and time to really do what we we're being able to do in other areas of heart failure and those patients with chronic, half and half where we can start developing pillars of therapy that can actually truly improve outcomes with this patient population and there is a lot going on that makes me optimistic that's going to be the case in the coming years. Dr. Greg Hundley: Very nice. And Brendan? Dr. Brendan Everett: Well, I think both trials mentioned today really pushed our understanding of this population forward. I think the biggest clinical question that I face when I'm caring for these patients is that we have four, at least, guideline directed therapies, right? We have beta blockers, we have ARBs, ACE inhibitors and ARNIs. We have mineral receptor antagonists and we have SGLT2 inhibitors. So which do we use in what order and how do we start them, and what kind of parameters do we use to guide us if we're limited either by renal function or by blood pressure or by some other factor. And we often, if not always, have one of those constraints that we're dealing with and so I would say the next step for me is trying to sort out which of these therapies and what order ought to be our highest priority for patients with acute decompensated heart failure as we move quickly from the acute decongestion stage towards discharge and a chronic therapy that will then be followed as an outpatient over the ensuing days and months. Dr. Greg Hundley: Very nice. And Christian. Dr. Christian Schulze: Thank you again, and Brandon pointed out very nicely. I mean, we have good evidence now for chronic heart failure treatment. We have the four columns of heart failure medical therapy. Questions that remain open is what do we do with all these patients that are now guideline medicated, come to the hospital with an acute decompensation? Should we carry on with the medication? Should we terminate and in particular, should be carry on with full dose, 50% dose of SGLT2 inhibitors, and the next question is, what dose should we use, in fact, for SGLT2 inhibitors? Is it in group effects or is sotagliflozin comparable to empagliflozin, and then is there a role for a step by scheme that we initially have in high dose therapy that we then downgrade to 10 milligrams on the chronic heart failure treatments, and then of course, quality of life is very important. We should ask this question also in this patient population that is early on treated, do we see benefits that carry on in the outpatient setting and do we see an effect of early treatment on long term benefits? Dr. Greg Hundley: Justin? Dr. Justin Grodin: Well, I would have to agree with all of my colleagues here on this call. I think all have raised really good points, but I think one very simple, and I'll echo some of Brendan's statements, but one very simple question is we know that when we decongest people and initiate a negative salt balance in the hospital for decompensated heart failure, we cause neurohormonal activation and there are a lot of downstream untoward effects from chronic decongestive therapies, and I think one of the more compelling things is we still yet have defined what is the best way to decongest individuals with swelling or volume overload in the hospital. Here, we have compelling studies with SGLT2 inhibitors for quality of life and really, the way patients feel. And this is really what's important to them, and then something very pragmatic to clinicians and let's make people pee more, but I think one of the compelling questions, and I don't know if it will be answered, is we have a lot of choices for supplemental therapies and different diuretic strategies when patients come in the hospital for decompensated heart failure, and I do think that these studies do move the needle with SGLT2 inhibitors. I think that's abundantly clear, but we still don't know what is the best way to dry out my patient or make my patient pee so that they feel better, but I do think that these studies do at least set the stage that there's some compelling advantages to SGLT2 inhibitors. Dr. Greg Hundley: And then lastly, Stefan. Dr. Stefan Anker: Thank you. Besides the detailed points mentioned by many, and Christian, totally support 25 versus 10 milligram, how long 25 milligram, if at all in the future. Besides this, I'm interested in the big picture question. So what about the post myocardial infarct congestion/heart failure situation, and there will be two trials in the next 18 to 24 months that report on this, and my pet kind of area is actually to treat heart failure where nobody thinks it is heart failure, and what I mean is for instance, advanced cancer patients, cardiac wasting cardiomyopathy. So the heart failure in sick cancer patients, and indeed, we are planning to do exactly that now in a study focusing on hospice care patients to really improve the quality of life, the very thing focus here on the EMPULSE trial. Dr. Greg Hundley: Well, listeners, we want to thank our authors, Dr. Mikhail Kosiborod from Mid America Heart Institute in University of Missouri, and Christian Shults from the University Hospital in Jena, Germany. Also, our associate editors, Dr. Brendan Everett from Brigham and Women's Hospital in Boston, and Dr. Justin Grodin from University of Texas Southwestern in Dallas, Texas, and also, our editorialist, Dr. Stefan Anker from Charité in Berlin, Germany for bringing us these two manuscripts pertaining to two randomized clinical trials regarding the administration of the SGLT2 inhibitor, empagliflozin in acute heart failure, demonstrating first, marked improvement in heart failure symptoms and health related quality of life. And second, in those with estimated GFRs greater than 30 mls per minute, an augmentation of natriuresis in the setting of the co-administration of diuretics without deterioration in renal function. Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Ambarish Pandey and Editorialist Linda Peterson as they discuss the article "Frailty Status Modifies the Efficacy of Exercise Training Among Patients with Chronic Heart Failure and Reduced Ejection Fraction: An Analysis from the HF-ACTION Trial" and the editorial "Heart Failure With Reduced Ejection Fraction (HFrEF): ‘The Importance of Being Frail.'" Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast, summary, and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature article, Heart Failure Reduced Ejection Fraction in Evaluating the Efficacy of Exercise Training. But guess what? It appears it may be more efficacious in those that have high Frailty Index scores, as opposed to those that may not. But before we get to our feature discussion, let's grab a cup of coffee and go through some of the other articles in the issue. Would you like to go first? Dr. Carolyn Lam: I would love to, and this first paper is one that defines epigenetic biomarkers of lifelong cardiovascular health exposure and really contributes to our understanding of their roles in cardiovascular disease development. First though, a little quiz for Greg. So, Greg, what does DNA methylation mean to you? Dr. Greg Hundley: Well, Carolyn, DNA methylation. So, what I understand is these methyl groups get involved with our DNA and actually affect change over time that leads to phenotypic expression of, maybe, new traits. But I don't know. Maybe I'm not quite up to date. Dr. Carolyn Lam: Oh, you're perfect. Indeed, DNA methylation is a widely characterized epigenetic modification, which means exactly as you said. It's a regulatory modification to our DNA induced by environmental exposures and can affect gene expression. And this is the topic of today's paper by Doctors Zheng, Hou, and Lloyd-Jones from Northwestern University Feinberg School of Medicine and their colleagues. So, what they did is they studied blood DNA methylation at over 840,000 methylation markers measured twice over five years in participants of the CARDIA study. Epigenome-wide association analyses on a clinical cumulative cardiovascular health score were then performed in both CARDIA and compared in the Framingham Heart Study. Dr. Carolyn Lam: The authors identified 45 midlife DNA methylation markers associated with clinical cardiovascular health metrics, such as body mass index, blood pressure, blood glucose, and total cholesterol longitudinally measured since young adulthood. The methylation markers were located in genes involved in lipid metabolism, insulin secretion, and cytokine production, which could not be fully attributed to genetic factors. So, they proposed and validated in summary a methylation-based risk score to promote a personalized cardiovascular disease risk evaluation beyond traditional cardiovascular risk factors. Dr. Greg Hundley: Oh, wow, Carolyn. Interesting, a methylation-based risk score to promote personalized cardiovascular disease risk evaluation. Wow! That's really exciting. Dr. Greg Hundley: Well, I'm going to go to the world of preclinical science, and just like last week where we had a really nice article on myocardial regeneration, this week, we've got another. And so, Carolyn, early neonates of both large and small mammals are able to regenerate the myocardium through cardiomyocyte proliferation for only a very short period after birth. This myocardial regenerative capacity declines in parallel with withdrawal of cardiomyocytes from the cell cycle in the first few postnatal days. No mammalian species examined to date has been found capable of a meaningful regenerative response to myocardial injury later than one week after birth. Dr. Carolyn Lam: Interesting. Now, I see that these investigators worked with possums. Could you tell me why they did that, and what did they find, Greg? Dr. Greg Hundley: Right, Carolyn. So, this work was led by Dr. Wataru Kimura from the RIKEN Center for Biosystems Dynamic Research and their colleagues. The reason they studied possums, so the marsupial possum maintains cardiomyocyte proliferation and a capacity for myocardial regeneration for at least two weeks after birth. Remember we stated before, all the other mammalian species, it's only one week after birth. So, this appears to be the longest postnatal duration of such a capacity among mammals examined to date, and AMP kinase signaling was implicated as an evolutionary conserved regulator of mammalian postnatal cardiomyocyte proliferation. Dr. Greg Hundley: And they additionally found that in a separate mouse experiment, the authors noted that the pharmacological inhibition of AMP kinase signaling was sufficient to extend the postnatal window of cardiomyocyte proliferation in neonatal mice, so really exciting work in the area of cardiomyocyte regeneration. Dr. Carolyn Lam: Wow, indeed! And I've learned now about possums. Thank you, Greg. Dr. Carolyn Lam: So, Greg, have you ever asked yourself, what is the frequency, penetrance, and variable expressivity of dilated cardiomyopathy-associated gene variants in the general population? Well, guess what? This next paper addresses just that in more than 18,600 UK Biobank participants who had undergone whole-genome sequencing, ECG, and cardiovascular magnetic resonance imaging. Dr. Greg Hundley: Wow, Carolyn, another really interesting study from the UK Biobank. So, what did they find? Dr. Carolyn Lam: So, this study is from Dr. Chahal from the Center for Inherited Cardiovascular Diseases Wellspan Health in Lancaster, Pennsylvania and colleagues, and they found that approximately one in six of adults with putative pathogenic variants in dilated cardiomyopathy genes exhibited early dilated cardiomyopathy features potentially associated with the genotype. And it's most commonly manifesting with arrhythmias in the absence of substantial ventricular dilation or dysfunction. Dr. Carolyn Lam: Among individuals with putative pathogenic dilated cardiomyopathy gene variants, ECG or CMR-detected early features were nearly four times more common than clinically manifest dilated cardiomyopathy or early features. Over 90% of subjects with these gene variants in dilated cardiomyopathy-associated genes did not have a prior history of dilated cardiomyopathy, and the overall clinical or subclinical penetrance of dilated cardiomyopathy-associated single pathogenic variants was highly variable between genes ranging from zero to 67%. And so, in conclusion, a genotype-first screening approach for dilated cardiomyopathy using a large genetic panel is currently not suitable in the general population due to incomplete understanding of the genetic architecture and reduced penetrance of the associated genes. Dr. Greg Hundley: Very nicely said, Carolyn. Wow! Well, let's take a look and see what's in the mailbag. And first, there's a Research Letter from Professor Huguenard entitled, “Frequency of Screening Detected Intracranial Aneurysms in Patients With Loeys-Dietz Syndrome.” And our own Bridget Kuehn has a really nice piece on Cardiology News. Dr. Carolyn Lam: Nice. There's also an On My Mind paper by Dr. Sattar, McGuire, and Gill entitled, “High-Circulating Triglycerides Are Most Commonly a Marker of Ectopic Fat Accumulation: Connecting the Clues to Advanced Lifestyle Interventions,” and an exchange of letters between Dr. Groothof and myself, Dr. Lam, regarding my article on “Efpeglenatide and Clinical Outcomes With and Without Concomitant SGLT-2 Inhibition in Type 2 Diabetes: An Exploratory Analysis of the AMPLITUDE-O Trial.” Dr. Carolyn Lam: Ah, that was awesome. Well, thanks, Greg. I am so excited to get to the future discussion that you queued us on so well, frailty in heart failure with reduced ejection fraction. Here we go. Dr. Greg Hundley: You bet. Dr. Greg Hundley: Welcome, listeners, to this July 12th, 2022 feature discussion. And we have with us today, Dr. Ambarish Pandey from University of Texas Southwestern Medical Center in Dallas, Texas, and Dr. Linda Peterson, an editorialist for this article from Washington University in St. Louis. Welcome to you both. Well, Ambarish, We're going to start with you. Could you describe for us basically the background information that went into the preparation of your study, and what was the hypothesis that you wanted to address? Dr. Ambarish Pandey: Thanks, Greg, for having me on this, and thanks to Circulation for publishing our article. Yeah, I think the premise for this study stems from the longstanding known benefit of exercise training in patients with heart failure with reduced ejection fraction. Now, that was shown in the HF-ACTION trial, where individuals with chronic stable heart failure with reduced ejection fraction underwent exercise training, and there was demonstrated benefit in quality of life and adjusted analyses. There was a protocol-specified adjusted analysis that did demonstrate improvement in some of the key primary endpoint. Dr. Ambarish Pandey: Based on these results, CMS has approved exercise training and cardiac rehabilitation in patients with chronic stable heart failure with reduced ejection fraction. However, despite this mandate from CMS and generally well-accepted benefits of exercise training in heart failure with reduced ejection fraction, the uptake of exercise training has been pretty low, and there's a lot of heterogeneity in the improvement in outcomes that is associated with exercise training. Dr. Ambarish Pandey: So, we wanted to see whether frailty, which is a well-characterized syndrome of reduced physiologic reserve and impaired homeostatic tolerance to stressors and is common in patients with HFrEF, we wanted to see how frailty modifies the beneficial effects of exercise training in HFrEF. And based on the existing literature and some of the prior works we have done, we hypothesized that individuals who are frail and who have more functional impairments are going to have more targets for improvement in their functional status and thus would be more likely to benefit from exercise training. And we looked at this in the HF-ACTION trial itself and using the Rockwood Frailty Index and the difference in primary outcome and treatment effect of exercise among frail and non-frail individuals. Dr. Greg Hundley: Very interesting, so really sort of a look back in HF-ACTION data. Describe a little bit more for us that study design, and then specifically, what was the study population that you used to test your hypothesis? Dr. Ambarish Pandey: Right. So HF-ACTION was a randomized control trial multi-centered that was sponsored by NHLBI and was conducted in the early 2000s and basically focused on chronic stable patients with heart failure with reduced ejection fraction who have not had a hospitalization in the past six weeks and have ejection fraction less than 35% and class II to IV. And these participants were randomized in one-to-one fashion to getting aerobic exercise training followed by some home-based exercise versus the usual care. Dr. Ambarish Pandey: And in our study, what we looked at was we looked at the effect modification by baseline frailty status on the treatment effect of exercise training. So, we calculated the frailty index, which is a well-established measure of frailty using a Rockwood Index Model, and we stratified patients by frail versus non-frail status based on a Frailty Index cut-off of 0.21, such that higher index identifies more frail participants. And then, we looked at how the treatment benefit of exercise training on different outcomes was differential across the frail and non-frail strata. We looked at qualitative interaction, and we also looked at the Frailty Index, so the continuous variable to assess the benefits of exercise across the spectrum of frailty in the study population. Dr. Greg Hundley: And so, before we get to your study results, how many patients were in your study? Give us an idea of what was the range in age, and then also the composition of sex? How many men? How many women? Dr. Ambarish Pandey: Right, so this is really important because that's addressed to the generalizability of the study. So, the study included around a little over 2,100 participants. The mean age was 59 years. 28% were women, and 32% were self-reported black individuals with chronic stable heart failure. That was the demographic distribution. The age was slightly younger than what you've commonly see in observational studies with heart failure, and that is largely because the study recruited patients who were able to do exercise training and were able to do exercise tests with peak VO2 and peak VO2 peak excess capacity assessment at baseline and follow-up. So, that kind of selected for a slightly younger population. Dr. Greg Hundley: Very nice. And so, what were your study results? Dr. Ambarish Pandey: So our study results are, indeed, pretty interesting. We identified that around 60% of patients with chronic stable heart failure with reduced ejection fraction who were in the trial were actually frail based on the Rockwood Frailty Index Model. And we observed that among the study participants, the exercise training was associated with significant improvement in the primary composite endpoint of all-cause hospitalization or death in frail participants, but not in the non-frail or less fail participants. And there was a significant treatment interaction, such that baseline frailty modified the treatment effect of exercise training for the primary composite endpoint. Dr. Ambarish Pandey: Now, this was largely driven by a significant reduction in all-cause hospitalization among frail individuals who underwent exercise training, and not so much by an effect on mortality. And we did not see a significant difference in the mortality component of the primary composite endpoint across frail versus non-frail status participants. So, in a nutshell, baseline frailty did modify the treatment effect, largely driven by substantial reduction in the risk of all-cause hospitalization among frail participants more than non-frail participants. Dr. Greg Hundley: And before we get to Linda in her interpretation of your study, Ambarish, did you see the same effects in frail men, in frail women? And also, what about in individuals that might be a little older versus those that were perhaps younger? Dr. Ambarish Pandey: That's a really important question, and we were a little bit limited to do further subgroups because we are dealing with around, I think, 2,000 participants and we had frail, non-frail, and we did not do a further subgroup stratification by sex or by age. The age range was rather narrow. It's 58 years plus/minus 13 years, so we didn't really have a lot of older individuals above 75, something like what REHAB-HF Trial has shown in the news, a recent trial. Dr. Ambarish Pandey: We couldn't address the question of whether the effect modification was further modified by sex or age, so I think that's the two-level interaction. But I think that is something that would be interesting to test perhaps in a pool analysis of multiple exercise training studies, which is something we are considering. Dr. Greg Hundley: Thank you. Well, listeners, now we're going to turn to our editorialist, Dr. Linda Peterson, from Washington University in St. Louis, and, Linda, very provocative results here, heart failure reduced ejection fraction. And certainly, we like to go to things like cardiac rehab, but we're hearing this it seemed to make a difference if you were frail versus not frail. Dr. Linda Peterson: Right, I think that's an important distinction here in this article as Ambarish has so eloquently put forth, and it's especially important because other articles have shown in looking at the PARADIGM-HF Study and ATMOSPHERE it appears that one out of two patients with HFrEF are actually frail. And so, the magnitude of these findings and the importance of these findings is highlighted by that study. And this frequency of frailty is roughly double that of community-dwelling adults who are over age 90, so we're thinking of frailty usually as much older adults, but in HF-ACTION, actually, the patients' average age was 60 in the patients with HFrEF. Dr. Linda Peterson: So, there's almost an accelerated aging phenotype we're seeing here in a large proportion of the patients who have HFrEF. I think this has an enormous impact on a lot of the patients that we're seeing with HFrEF, and we should be alerted to looking for frailty and potentially screening for frailty. And I think another highlight of this study is that it points out the importance of frailty because frail patients have a 50% higher risk of hospitalization and death, according to some other studies, particularly one by Faray and their group and also by Yang and their group. Dr. Linda Peterson: And so, it highlights the importance of getting patients who are frail with HFrEF into cardiac rehab or getting them some sort of aerobic exercise training. But paradoxically, frailty is also associated with a lower likelihood of those particular patients on getting into cardiac rehab and also getting on goal-directed medical therapy. And that was shown by Phil Ades and his group. So, I think the importance of these findings by Ambarish and his group are to be commended, and they're very important for a large proportion of our patients with HFrEF. Dr. Greg Hundley: Very nice. Well, let's turn back to Ambarish, and then follow up with Linda. Ambarish, what do you see as the next study that should be performed in follow-up to your study? Dr. Ambarish Pandey: I think that's a great question. And I think we are just beginning to realize the magnitude of impact that frailty has in the care of patients with heart failure. And this goes across the spectrum of ejection fraction, both HFpEF or heart failure with preserved ejection fraction and heart failure with reduced ejection fraction. Indeed, the burden of frailty is higher in patients with heart failure with preserved ejection fraction, and they are more of the accelerated aging phenotype. Dr. Ambarish Pandey: And I think the next study basically should look at a targeted approach to exercise training or category of intervention among patients who are most likely to benefit from it, which would be patients who have a high frailty burden or patients who have HFpEF. I think they go hand in hand when it comes to frailty and HFpEF. So, I think that's the next study to do is to see to what extent we can actually identify and target exercise training in the highest risk individuals who are most likely to benefit from it because that subset of highest modifiable risk is indeed identified by frailty and when you look at other subtypes by HFpEF which has a lot of high frailty burden. Dr. Greg Hundley: And, Linda, from your perspective, what do you see as the next study to be performed in this sphere of research? Dr. Linda Peterson: Yeah, I think this study really provides a springboard for future studies in HFrEF, in particular. One, what hospital interventions can be done in patients to get them moving more, and really assess is there a possibility of different types of exercises to get patients less frail even while they're in the hospital when they're enroute to going home? And then also, how do we have different mechanisms by which we can get more patients into cardiac rehab? Clearly, our national average of getting patients who qualify for cardiac rehab, which is a class I indication is 20% at best, and the aim from the AHA is 70%. Dr. Linda Peterson: There's a big gap there, so interventions looking at implementation and getting patients to cardiac rehab or looking at other types of aerobic exercise training, such as home-based cardiac rehab for patients who don't have a cardiac rehab center next to them, I think the field is wide open for different studies to springboard off of these findings. Dr. Greg Hundley: Very nice. Well, listeners, we want to thank Dr. Ambarish Pandey from University of Texas Southwestern Medical Center in Dallas, Texas, and our editorialist, Dr. Linda Peterson, from Washington University in St. Louis, for bringing us this research study, highlighting that among patients with chronic stable heart failure and reduced ejection fraction, that baseline frailty modified the treatment effect of aerobic exercise training with a greater reduction in the risk of all-cause hospitalization. Dr. Greg Hundley: Well, on behalf of Carolyn and myself, we want to wish you a great week, and we will catch you next week on the run. Speaker 5: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
At the beginning of her career, Prof Lam thought that being able to multi-task is one of her strengths. After many accomplishments as a cardiologist and a researcher, she believes that there is more power in focus and being fully present. This week's guest on Parallax is Professor Carolyn Lam, Senior Consultant and Director of Women's Heart Health at the National Heart Centre Singapore, Professor at the Duke-National University of Singapore and co-founder of Us2.ai, an award-wining medtech start-up as well as the host of the Circulation on the Run Podcast. In this refreshing and spiritual episode Carolyn reflects on her journey and the decisions and mentors that shaped her career as a heart failure specialist, trialist and as a public speaker. Ankur and Carolyn dive into the question whether being balanced is what we should be all aiming for. Ankur asks Carolyn about her work as a co-founder of Us2.ai, a start-up dedicated to the automation of the fight against heart disease by applying AI to echocardiography. What makes Prof Carolyn Lam tick? What does spirituality and faith mean to Prof Lam? What are her thoughts on the role of AI in the democratization of medicine? What is her advice to our listeners? Questions and comments can be sent to “podcast@radciffe-group.com” and may be answered by Ankur in the next episode. Guest, @lamcardio hosted by @AnkurKalraMD. Produced by @RadcliffeCARDIO.
This week, please join author Fabian Eichelmann and Associate Editor Svati Shah as they discuss the article "Deep Lipidomics in Human Plasma: Cardiometabolic Disease Risk and Effect of Dietary Fat Modulation." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast, summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor Director at the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature, we are going to get into the world of lipidomics and understand how some lipid metabolites may be more predictive of cardiovascular events above and beyond the conventional serum lipoproteins, like HDL and LDL. But before we get to that, how about we grab a cup of coffee and start with some of the other articles in the issue? Would you like to go first? Dr. Carolyn Lam: Sure thing. This first paper is about the basilar artery. Have you ever heard the analogy that the basilar artery is the neurologists' equivalent of our cardiologists' left main coronary artery? Well put, isn't it? Well, that's from the editorial that accompanies this paper, but basically, occlusion of either artery can be fatal without rapid re-perfusion. So that's why the basal artery is the neurologists' left main coronary artery. Re-perfusion therapies for acute basilar artery occlusion include thrombolysis or mechanical endovascular thrombectomy. Dr. Carolyn Lam: In today's issue, Professor Hu from University of Science and Technology of China, and Professor Nogueira from University of Pittsburgh School of Medicine in the US, these are the co-corresponding authors, and their colleagues, reported the outcome of the attention registry of more than 2000 patients with acute basilar artery occlusion who enrolled prospectively and consecutively at 48 sites in China from 2017 to 2021, and followed for the primary outcome of a favorable neurological functional outcome defined as a modified Rankin score of zero to three at 90 days. Dr. Greg Hundley: Wow, Carolyn, I love that analogy. So the basilar artery is kind of similar in the brain to the left main coronary artery in the heart. Whoa, what did they find here? Dr. Carolyn Lam: So, in this nationally representative observational study, the authors found a significant association between endovascular thrombectomy and better functional outcomes and survival at 90 days in patients with acute basilar artery occlusion, and this was compared to chemical thrombolysis. Now, notably, this relationship was modified by the baseline NIH stroke scale. Specifically, patients with baseline NIH stroke scale of 10 or more had an increased rate of favorable outcome when treated with endovascular thrombectomy, whereas no significant beneficial effect was seen in patients with baseline NIH stroke scores of less than 10. Now, all this is discussed in a beautiful editorial by Dr. Hankey, entitled, "Endovascular therapy for acute basilar artery occlusion." Dr. Greg Hundley: Oh, beautifully stated, Carolyn. What a great article. But guess what, Carolyn? I've got a quiz for you. Dr. Carolyn Lam: Uh-oh. Dr. Greg Hundley: This one's open answer, so it's not multiple choice. Can you name a unique feature of zebra fish pertinent to the study of cardiovascular disease? Dr. Carolyn Lam: Okay. Watch me hedge there because, first of all, I'm a daughter of a zoologist. So my dad would have a heart attack if I couldn't say something about the zebra fish. So, what I do know is the zebra fish is an excellent animal model for genetic studies of heart generation, basically development. So, there must be something really cool there about how we can observe that. Dr. Greg Hundley: Excellent, Carolyn. So very well done. As you know, and your dad knows, certain non-mammalian species like zebra fish, have an elevated capacity for innate heart regeneration. Now, understanding how heart regeneration occurs in these contexts can help illuminate cellular molecular events that can be targets for heart failure prevention or treatment, your area of expertise. The epicardium, the mesothelial tissue layer that encompasses the heart, is a dynamic structure that is essential for cardiac regeneration in zebra fish, and these authors, led by Dr. Jinhu Wang from Emory University performed single cell RNA sequencing and identified seven epicardial cell clusters in adult zebra fish, three of which displayed enhanced cell numbers during regeneration. Dr. Carolyn Lam: Oh, interesting, Greg. So did these cell clusters provide some clues that could be applied clinically? Dr. Greg Hundley: Yes. Carolyn. So these authors identified that these subsets of epicardial cells emerge in post embryonic, zebra fish and sponsor regions of active cardio myogenesis during cardiac growth and regeneration. And as the heart achieves its mature structure, these cells facilitate extracellular matrix hyaluronic acid deposition to support formation of the compact muscle layer of the ventricle. These cells associate with the function of the hyaluron and proteoglycan link protein 1 or HAPLN1 paralogue in production and organization of hyaluronic acid containing matrix in cardiac injury sites and thereby enable normal cardiomyocyte proliferation and muscle generation. And so Carolyn, potentially in the future targeting hyaluronic acid regulation by manipulation of HAPLN1 in human epicardial cells could potentially modulate cardiac repair after myocardial infarction. Dr. Carolyn Lam: Well, thanks, Greg. That was awesome. Well, the next paper I want to tell you about is one in which a novel ECG based machine learning approach was used to determine and predict multiple structural heart conditions. So the authors led by Dr. Chen from Department of Translational Data Science and Informatics at the Geisinger Health System in Danville, Pennsylvania. So these colleagues hypothesized that a composite model would yield higher prevalence and positive predictive value to facilitate meaningful recommendations for echocardiography. Dr. Greg Hundley: Oh wow, Carolyn. Machine learning, it's just emerging everywhere these days. So don't we need a large data set to do this? Dr. Carolyn Lam: Absolutely, and listen to how large this is. So using more than 2.2 million ECGs linked to electronic health records and echocardiography reports from almost 500,000 adults between 1984 and 2021, the authors trained machine learning models to predict the presence or absence of any of seven echo confirmed diseases within a year, and the composite model and the composite label that they used included moderate or severe valve disease and reduced ejection fraction. So their composite recommend model where reco is E-C-H-O we used age, sex ECG traces, and had an area under the receive operating curve of 0.91 and a positive predictive value of 42% at 90% sensitivity with a composite label prevalence of 17.9%. Whereas the individual disease models had area under curve ranging from 0.86 to 0.93 and lower positive predictive values from about 1% to 31%. Dr. Carolyn Lam: So in summary, they showed that an ECG based machine learning model using a composite endpoint can identify a high risk population for having undiagnosed clinically significant structural heart disease while outperforming the single disease models and improving practical utility with higher positive predictive values. So this approach may facilitate targeted screening with echo to improve under diagnosis of structural heart disease. Dr. Greg Hundley: Wow, Carolyn, really great article from the world of machine learning. Well, how about we jump to some of the other articles in the issue and I can go first. There are two Research Letters. The first Research Letter comes from Professor Adlam entitled "Pregnancy and Spontaneous Coronary Artery Dissection Lessons from Survivors and Nonsurvivors." And our own Dr. Joe Hill, our Editor-in-Chief also has a Research Letter entitled “Impaired AMP Kinase Signaling in HFpEF Associated Atrial Fibrillation.” Dr. Carolyn Lam: Wow, what an issue filled with great stuff. There's an AHA update by Dr. Churchwell on promoting nutrition security through policies and programs. And there are highlights from the circulation family of journals by our own Molly Klemarczyk, now known as Molly Robbins. I'd love to tell you a little bit about it. The association of new onset AF with cardiovascular outcomes in patients hospitalized with COVID-19 are described in Circ Arrhythmia, and EP. Rates of cardiovascular and cerebral vascular disease mortality among Asian subgroups are presented in Circ CV, Quality and Outcomes. Blood pressure and glycemic control are presented in patients with heart failure in Circ Heart failure. The associations of atrial update with technetium 99 pyrophosphate scans for transthyretin amyloid cardiomyopathy with incident atrial fibrillation and possibly earlier diagnosis of amyloid is presented in Circ Cardiovascular Imaging. Dr. Carolyn Lam: And finally the outcomes associated with larger burdens of residual thrombus after aspiration thrombectomy for STEMI are presented in Circ CV Interventions. Isn't that cool? And finally, we've got an On My Mind paper by Dr. Arany on “It's Time to Offer Genetic Testing to Women with Peripartum Cardiopathy”. So that wraps it up, Greg. Let's go to our feature discussion, shall we? Dr. Greg Hundley: You bet. Dr. Greg Hundley: Welcome listeners to this feature discussion on July 5th, and we are very fortunate today. We have with us Dr. Fabian Eichelmann from the German Institute of Human Nutrition in Potsdam, Germany, and our own associate editor, Dr. Svati Shah from Duke University in Durham, North Carolina. Welcome to you both. Fabian, we're going to start with you. Can you describe for us some of the background information that went into the preparation of your study and what was the hypothesis that you wanted to address? Dr. Fabian Eichelmann : Yeah, sure. So first of all, thanks for the invitation to speak here. So this project was basically comes from a collaboration between us and a group in Redding, UK and we are part of a consortium called FAME, which is short for fatty acid metabolism. And there, we are interested in the health effects of fatty acid metabolism in general. And in this paper that we did, this was particularly cardiometabolic diseases. And I think this is no surprise that we look at lipid metabolism in this context, because there's so many really now also causal factors, lipoproteins, total triglycerides for specific cardiometabolic outcomes. So this is the reason why we wanted to look at it. And through this collaboration, we were also able to harness the potential from two different study designs that I probably will go into later, but which really gave us an opportunity to really generate I think, quite interesting insights. Dr. Greg Hundley: Very nice. And so what was that hypothesis? Dr. Fabian Eichelmann: So the hypothesis was that since the lipid metabolism has formally only been mostly in the clinic, at least been measured by lipoproteins and total triglycerides, for example, but the lipidome of plasma, for example, is really rich. It's really heterogeneous and it contains many different lipid classes and different fatty acids. And through novel technologies and in this case, lipidomics, you can really dive in really deeply and look at this in a specific manner. And then the idea was to really look at this and potentially identify lipids that would be associated or could surface as biomarkers for cardiometabolic diseases and at the same time, if those lipids were also sensitive to a dietary intervention that really tried to modulate the dietary intake of a fat. Dr. Greg Hundley: Very nice. And so how did you set this up? What was your study design and what was your study population? Dr. Fabian Eichelmann: So we had two different study populations for this. So the first one was the EPIC-Potsdam, which is a cohort study, a large scale cohort study here in Potsdam, which started in the nineties. And there, we basically associated baseline concentrations of these lipid measurements with later on occurring incident cardio metabolic outcomes. And in this case, this was type two diabetes and primary CVD and CVD in our case meant myocardial infarction and stroke. And we did that we checked which lipids would be statistically significantly associated after multiple testing with at least one of these outcomes. And then we took those lipids further into intervention trial, which is called the DIVAS trial in Redding, as I said, UK. And there, they had basically a dietary intervention trial that really wanted to assess if the change in the fatty acid proportions in the diet affects the lipids. So there we had the lipidomics measurements at baseline and after four months, and then we compared three different trials to each other. Dr. Greg Hundley: Very nice. And so how many patients did you include and who were these patients? Men and women? And did they have, for example, prior cardiovascular disease? Dr. Fabian Eichelmann: So in EPIC-Potsdam, that's a population based cohort study. All of the participants were drawn from the registries and invited. So these were apparently healthy people. And in those we did these association analyses and those we used the design, which is a case cohort design, which is a sub sample of the whole cohort, which is a really effective way and efficient way of analyzing biomarker projects. And there we had in total 1,262 control participants, and then later on additionally, a 775 type two diabetics and 551 CVD cases. In the DIVAS trial, that was a trial where participants also men and women, which was also the case in EPIC-Potsdam were invited, and they were at a higher risk of at the higher cardiovascular disease risk, which was measured by score, but they didn't have any prior cardiovascular diseases. And those were 113 participants that were randomized to one of these diets. Dr. Greg Hundley: Right. So it sounds like two studies. One, a large case control study and looking at different plasma lipid concentrations in two separate groups. And then the second was a randomized trial, a smaller trial of 113 individuals looking at a dietary intervention. So with that established, tell us your study results. Dr. Fabian Eichelmann: Yeah. So in the first step, as I said, where we associated lip concentrations to later occurring disease, we found from the 282 lipids that we looked at, 69 were really associated to at least one of these outcomes. And interesting here we saw that only eight were associated to both outcomes and 49 were specific to cardiovascular disease and 12 for specific to type two diabetes. And from those 69, we found 19 were also sensitive to the dietary intervention, and what was really striking here was that of these 19, 17 were perfectly in agreement with a suggested beneficial effect, meaning that those lipids that were associated in the EPIC-Potsdam studies on the cohort study with a higher disease risk were reduced by these diets or in the opposite direction, we saw those lipids that were associated with lower risk were increased by these diets. So this was quite a striking observation there. Dr. Greg Hundley: So it sounds like from the lipidomics analysis, there was a construct of certain blood lipid markers that were associated with cardiovascular events, and then in your randomized trial, you were able to modify those by different dietary interventions? Dr. Fabian Eichelmann: Exactly. Dr. Greg Hundley: So listeners, now we're going to turn to our own associate editor, Dr. Svati Shah. And Svati, you see many papers come across your desk. What attracted you to this particular paper and how do we put this study's results in the context with other studies that have been published in really the sphere of lipidomics research? Dr. Svati Shah: Yeah. Thank you, Greg. I just want to point out that this is a really elegant translational study. I think these papers can be very complicated to understand, and I think the authors did a fantastic job of really laying out how you can combine cutting edge what we call omics, using these cutting edge technologies, but applying them to human cohorts with a very strong clinical lens. So it's not just what do we learn about biology, but also what do we learn about biomarkers that might be relevant to how we take care of patients? And that's really one of the biggest things I loved about this study is sort of, you get to have your cake and eat it too. You get to learn about biology, but with a very strong clinical lens towards identifying clinically relevant biomarkers. I think another really important strength of this study, which differentiates it is this sort of use of really cutting edge lipidomics. Dr. Svati Shah: So this is a subset of omics where we're really looking at these granular lipid classes. And some of the clinicians might say, well, we measure cholesterol, why is this different? And you know, Greg, really what lipidomics allows us is a much more granular snapshot of these complex lipid species that are only grossly captured by the cholesterol levels that we would measure normally if we were seeing a patient in clinic. So to be able to get this really granular snapshot of what is happening to lipid biology and how it might relate to cardiovascular events, diabetes, I think is really important. And finally, I think the coolest part about this study is, in other studies we always have a little bit of a hard time with what we call confounders. And what does that mean? That means there may be other things for why you're seeing these biomarkers associated with your disease and those might be uncaptured things, things that you didn't measure in this study. And we call that residual confounding. Dr. Svati Shah: And I think the authors in this study, not only statistically adjusted for those potential confounders, but also importantly, the DIVAS study, where they took the biomarkers that they found from EPIC-Potsdam and said, do they change with the dietary intervention? And in fact, they did find that many of these lipid, these granular lipid species improved, meaning they went in the proper direction in terms of your health with a diet that was higher in unsaturated fats. So really proving not only the potential biology of the benefit of diets enriched in unsaturated fats, but also that these particular biomarkers are modifiable, so they're able to be changed even in this case within 16 weeks with just a dietary intervention. So to me that really was just a beautifully laid out study that highlights really what translational omics and these biomarker studies can do as we think about the clinical care of patients. Dr. Greg Hundley: Very nice. And so it sounds like listeners, moving beyond the lipoproteins, LDL, maybe total cholesterol and these granular lipid species cholesterol esters, free fatty acids, fingo-lipids, glycerophospholipid, et cetera, that's what we were studying in this particular manuscript. So, well, let's turn back to Fabian. And Fabian, what do you see is the next study to really be performed in this sphere of research? Dr. Fabian Eichelmann: I think what would be really interesting and what would really kind of prove what we saw is if you could find a way that an intervention, be it like a drug intervention and not diet because we looked at dietary intervention, that kind of shows the same as we saw, but also that really specifically only alters these lipids and how obviously not really feasible, but if that would be going on for a long enough period, if you also saw these effects that we now saw after four months would also affect the health outcomes instead of just only these proxies. Dr. Greg Hundley: Very nice. And Svati, how about you? What do you see as the next study that might be informative in this sphere of research? Dr. Svati Shah: Yeah. Great question, Greg. I mean, to me, I really think about this gap that we have in actually translating these findings in how we take care of patients. So again, really provocative results here. We have really significant P values, strong effect sizes, biomarkers that are modifiable, but in the paper they show that it adds on top of a clinical model, so what we might use as clinicians in the clinic that these biomarkers may help on top of what we already know about patients. But we really need to implement these findings and study that implementation for how this might in a real world setting actually change outcomes in patients and how we can actually help explain to clinicians how these results might be beneficial for clinical care. Dr. Svati Shah: So on top of what Fabian already said, I think really implementation science is a huge gap in how we take these translational omics discoveries and use them in support of improving patient care. We have lots to learn about these lipid biomarkers and lots more discovery science that can be done. As Fabian said, can we find drugs that might beneficially modified these lipid subspecies? But again, I think this gap in implementation science is really important. Dr. Greg Hundley: Very nice. Well listeners, we want to thank Dr. Fabian Eichelmann from the German Institute of Human Nutrition in Potsdam, Germany, and our own associate editor, Dr. Svati Shah from Duke University in Durham, North Carolina for bringing us these really provocative results, highlighting the identification of several lipids and their association with cardiometabolic disease risk. And then also nested within the same paper, a subset of individuals undergoing a randomized clinical trial demonstrating benefit by a dietary fat intervention, and there possibly supporting the substitution of dietary saturated fatty acids with unsaturated fatty acids perhaps as a potential tool for primary disease prevention. Dr. Greg Hundley: Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. Dr. Greg Hundley: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Ratika Parkash and Editorialist Sean D. Pokorney as they discuss the article "Randomized Ablation-Based Rhythm-Control Versus Rate-Control Trial in Patients with Heart Failure and Atrial Fibrillation: Results from the RAFT-AF trial" and the editorial "The Evidence Builds for Catheter Ablation for Atrial Fibrillation and Heart Failure." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor, from the National Heart Centre and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature discussion, oh, so exciting. We enter the month of June, and it pertains to heart failure and atrial fibrillation. And we are going to learn a little bit more from the RAFT-AF trial, involving randomizing patients to ablation and rhythm control, as opposed to just settling for rate control for patients with AFib. But before we do that, how about we grab a cup of coffee and start with some of the other articles in the issue? Would you like to go first? Dr. Carolyn Lam: I absolutely would. And I will start by asking everyone a question. Could a single high-sensitivity cardiac troponin T level, below the limit of detection of six nanograms per liter, exclude an acute myocardial infarction? Well, you are going to find out because, remember that data for excluding AMI with a single high-sensitivity cardiac troponin level relies largely on the limit of detection, which is really a threshold of five nanograms per liter, which cannot be reported in the United States, per the FDA, because there, only the lowest reportable concentration is allowed, which is the limit of quantitation of six nanograms per liter. Dr. Carolyn Lam: So, today's authors Dr. Sandoval from Mayo Clinic and colleagues, very cleverly sought to determine whether a single high-sensitivity cardiac troponin T level below the limit of quantitation of six nanograms per liter could indeed identify patients at low risk for AMI. Dr. Greg Hundley: Very interesting, Carolyn. So we have the limit of quantitation and then the limit of detection. This is really intriguing. And of course, cardiac troponin T, as cardiologists, we receive a lot of requests for consults on this. So, what did this study find, Carolyn? Dr. Carolyn Lam: A total of over 85,000 patients were first evaluated in the CV data marked biomarker cohort, amongst which 29% had a baseline high-sensitivity cardiac troponin T level below this limit of quantitation of six nanograms per liter. Among 11,962 patients with this baseline high-sensitivity cardiac troponin below six nanogram per liter and serial measurements, only 1.2% developed acute myocardial injury, resulting in a negative predictive value of 98.8% and a sensitivity of 99.6%. Dr. Carolyn Lam: In an adjudicated cohort, among those with a non-ischemic electrocardiogram, only 0.2% had myocardial infarction or death at 30 days. So in summary, Greg, this is the largest study evaluating a single high-sensitivity cardiac troponin T level below this limit of quantitation of six nanograms per liter to identify patients at low risk for AMI. Dr. Carolyn Lam: And indeed, the present study demonstrates that a single high-sensitivity cardiac troponin level below six nanogram per litter is a safe and rapid method to identify a substantial number of patients at very low risk for acute myocardial injury and infarction. Dr. Greg Hundley: Oh wow, Carolyn, really informative study. Well, Carolyn, my next study comes from the world of preclinical science. And Carolyn, vascular smooth muscle cell phenotypic switching contributes to cardiovascular diseases. And epigenetic regulation is emerging as a key regulatory mechanism with the methylcytosine dioxygenase Tet2, acting as a master regulator of the smooth muscle cell phenotype. Dr. Greg Hundley: The histone acetyltransferases, HATs p300, and CBP are highly homologous and often considered to be interchangeable. And their roles in smooth muscle cell phenotypic regulation are not known. So Carolyn, these authors led by Dr. Kathleen Martin from Yale University School of Medicine assessed the roles of p300 and CBP in human vascular smooth muscle cells with knockdown in inducible, smooth muscle specific knockout mice, and in samples of human intimal hyperplasia. Dr. Carolyn Lam: Cool, Greg. So what did they find? Dr. Greg Hundley: Right, Carolyn. So, they found that p300 and CBP serve non-redundant and opposing function in vascular smooth muscle cell phenotypic switching and coordinately regulate chromatin modifications through distinct functional interactions with Tet2 or HDACs. And Carolyn, targeting specific histone acetyltransferases therefore may hold therapeutic promise for future cardiovascular disease interventions. Dr. Carolyn Lam: Oh, that's great, Greg. Well, to round it all up, there are some other papers in today's issue. There's a Research Letter from Professor Zhang, entitled “Single Nucleus Transcriptomics: Apical Resection in Newborn Pigs Extends the Time-Window of Cardiomyocyte Proliferation and Myocardial Regeneration.” There's also a Research Letter from Dr. Vaduganathan, entitled “Estimating the Benefits of Combination Medical Therapy in Heart Failure with Mildly Reduced and Preserved Ejection Fraction.” Ah, that's such a cool issue. Now, let's go on to our feature discussion. Shall we, Greg? Dr. Greg Hundley: You bet, and learn a little bit more about rhythm versus rate control in patients with heart failure and atrial fibrillation. Dr. Carolyn Lam: Our feature discussion today is about the long-awaited results of the RAFT-AF trial, and that is the randomized ablation-based rhythm control versus rate control trial in patients with heart failure and atrial fibrillation. Thank you so much, Dr. Ratika Parkash for joining us today as the first and corresponding author from Queen Elizabeth II Health Sciences Center in Canada, as well as Dr. Sean Pokorney, the editorialist from Duke University. Dr. Carolyn Lam: I am so, so excited to be discussing this paper. I really meant it. You know, as a heart failure cardiologist, we've been waiting for these results and trying to understand everything in context. So maybe, Ratika, could you please start off by telling us about the RAFT-AF trial and what you found? Dr. Ratika Parkash: Thank you, Carolyn. I'm happy to be able to talk about this study on behalf of the RAFT-AF investigators and my co-PI, Dr. Anthony Tang. So the trial... First of all, the rationale for the study, I think many of us, as heart failure or heart rhythm specialists, understand that in the past, we've done many trials looking at rate versus rhythm control, the AFFIRM trial being the largest, and then of course, specifically in heart failure patients, the AF-CHF trial, both of which were negative in reducing cardiovascular events and mortality in patients with or without heart failure, in terms of a rate to rhythm control. Dr. Ratika Parkash: One of the issues with those trials is that the form of rhythm control was antiarrhythmic drugs. So we have learned that catheter ablation is superior to antiarrhythmic drugs in maintaining sinus rhythm. And based on that premise, we decided to go forward with the RAFT-AF study. Dr. Carolyn Lam: That's great, Ratika, so thanks. And what were the results? Dr. Ratika Parkash: The main finding, so the primary outcome of the study was mortality and heart failure events. Heart failure events was defined as a heart failure hospitalization or any escalation of heart failure therapy that was done in the outpatient settings, including the use of intravenous Lasix in an emergency department setting. Dr. Ratika Parkash: So the main findings were that ablation-based rhythm control was not statistically significant in reducing mortality and heart failure events over rate control in patients with atrial fibrillation and heart failure. The study included patients both with preserved ejection fraction, as well as reduced eject fraction. And we did stratify based on ejection fraction at the entry point into the trial. The hazard ratio was 0.71 and the 95% confidence interval just crossed unity, ranging from 0.49 to 1.03 with a P value of 0.066. Dr. Carolyn Lam: Oh, ouch. So, thank you. And again, truly, congratulations on a very, very important trial. Sean, I said it before, I'll say it again, really, really loved your editorial. Could you put these findings in the context of... Maybe, start with even the most recent guidelines, the 2022 ACC/AHA/HFSA heart failure guidelines, which I believe gives catheter ablation a class 2A recommendation. Maybe, start from there, and how does this fall in place? Dr. Sean Pokorney: Yeah, no, absolutely. I think, first of all, it's a really important trial and it's great to have this additional data. I do think, as you said, that it's important to understand the context. We now have several recent guidelines that have commented on the role of catheter ablation in patients with heart failure. Dr. Sean Pokorney: You mentioned the most recent heart failure guidelines. We also have additional AFib guidelines and we have the 2019 AHA/ACC/HRS guidelines for atrial fibrillation that give catheter ablation a 2B recommendation in patients who have heart failure, to potentially lower mortality and reduce hospitalization. And it has a 2A indication in the 2020 ESC guidelines. And we're currently undergoing some revisions of the guidelines for atrial fibrillation, and there'll be new guidelines around atrial fibrillation coming out from AHA/ACC/HRS in the coming years. And so that will also be helpful, I think, to incorporate some of this additional data. Sean Pokorney: When you really look at the guidelines and see what's driving the guidelines, there are several trials now that are really driving the guidelines. And so I think, looking back on the data, we have the AATAC trial, which was a trial of 203 patients that looked at ablation versus amiodarone. And we have the CASTLE-AF trial, which had 363 patients in it and was looking at atrial fibrillation in patients with heart failure with reduced ejection fraction and defibrillators. Dr. Sean Pokorney: And when you put that data into context, the AATAC trial did find lower rates of death and hospitalization as a secondary outcome, and CASTLE-AF did identify a reduction in heart failure hospitalizations and death. At the three year follow-up, there was a statistically significant reduction, although the event number was lower than the previously sort of calculated target sample size. Dr. Sean Pokorney: And so in aggregate, these trials do show a modest evidence of benefit for clinical outcomes in this population. And that's where adding more data is really critical. Dr. Carolyn Lam: That's so true. And actually, Ratika, is there any plan for some meta-analysis or sort of adding the data? And if you could, also speak to, the trial was interrupted at some point, so how that may have impacted things as well. Dr. Ratika Parkash: Those are important questions. So, first of all, there is a planned longer term follow-up for the study, to look at whether or not following these patients out beyond our meeting follow-up of 37 months, it will actually produce a different result than what we observed in the current findings. Dr. Ratika Parkash: I think a meta-analysis is obviously going to show benefit for ablation-based rhythm control, based on the data that Sean had just described. One of the things that we'd need to keep in mind is that this trial, the RAFT-AF study really enrolled patients who were suitable for either ablation-based rhythm control or rate control. So it wasn't a study that looked at rhythm control only. Dr. Ratika Parkash: So, the CASTLE-AF trial had essentially two rhythm control arms. The medical therapy arm was, was amiodarone in that trial, versus catheter ablation. So patients could get rhythm control in both. And so, the types of patients that would've gotten into CASTLE-AF were different than the patients in our trial, even when you look at the reduced ejection fraction patients. Dr. Ratika Parkash: Having said that, our curves, when you look at the reduced ejection fraction group in our study does mirror what was observed in CASTLE-AF. So, even if a patient is not deteriorating initially with rate control, it appears that over time they begin to deteriorate. And that's what all of these trials have shown, is that patients do better with ablation-based rhythm control, the best form of sinus rhythm maintenance that we have. Dr. Ratika Parkash: And it takes time for them to deteriorate and it takes time to accrue those events. And this is evident in all trials of atrial fibrillation. You either need a very large sample size, like 15,000 patients, to look at heart failure in a short period of time, or you follow them longer, so that you can accrue those events. Dr. Ratika Parkash: In terms of the stopping of the trial, certainly, had we reached the sample size of 600, which was the intended sample size after recalculation during the study from 1000 down to 600, I believe we would have reached a positive outcome. But again, we hope that our longer term follow-up might shed some light on that. The interruption of the study was based on the DSMC decision and certainly could have affected the power of the study. Dr. Ratika Parkash: We have to remember that the other possibilities are that ablation-based rhythm control is not superior to rate control. And as someone who is pro-ablation, it's difficult to say that, but we see hints of benefit and we have to recognize that. Dr. Ratika Parkash: The other issue is that the secondary endpoints in our trial were all significant, as overall, it doesn't matter which group you looked at, NT-proBNP, six-minute walk test, quality of life, both for heart failure and atrial fibrillation, as well as ejection fraction, were all improved. And for many of the studies that have been done previously, those were the primary endpoints of those studies. Dr. Ratika Parkash: The idea of whether ablation-based rhythm control reduces heart failure per se, is from our study, purely from our study, we can't be a hundred percent certain. There's definitely a hint of clinical benefit there. From all the secondary endpoints, which are the current guidelines, is what they indicate ablation should be done for, is to improve quality of life. Our study was certainly supportive of that. Dr. Carolyn Lam: You know, Sean, I especially appreciated your discussion of these issues, the early stopping of the trial, the secondary endpoints. Could you know, share some of those thoughts? Dr. Sean Pokorney: I think it's really an important topic. I think that, again, as Ratika said, part of why this trial is so important is that many of the previous trials that have been published and many of the data sets have really looked at rhythm control versus rhythm control in this population, even including the analysis from CABANA, which included almost 780 patients from CABANA that had heart failure. And in that population, they did show a reduction in the composite primary endpoint of death, disabling stroke, serious bleeding, or cardiac arrest. And again, CABANA was, as well, a study of rhythm control with ablation versus medical therapy, most patients getting rhythm control in that medical therapy arm. Dr. Sean Pokorney: And so this data really is additive. I think that one of the challenges is always, how do we make sure to get the most information out of a clinical trial once we commit patients to that scientific process? And I think here, at least in retrospect, it's obviously unfortunate that the trial was stopped early. I think that more data would certainly be helpful. Dr. Sean Pokorney: I appreciate the fact that longer term data may help solve that gap and close that gap a little bit. I think that, I guess, it'd be interesting to hear from Ratika a little bit more about the process that was involved with interaction with the DSMC and stopping the trial. Dr. Ratika Parkash: Yeah. Thanks, Sean. That also is a very good question. The DSMC really evaluated the data, evaluated the progress of the trial, back in 2017. It had been six years since we'd started the study. The data they had, in fact, did not show any benefit to ablation-based rhythm control over rate control at the time. So the follow-up period at the time was around two years. Dr. Ratika Parkash: And again, if you look at our Kaplan-Meier curves, you can understand why they would have made that decision at the time, based on 363 patients for the data that was available to them. They had a futility index that they looked at. it was calculated. The cutoff for stopping of the study was 0.8, and it was 0.81. So, there was a 19% chance that the study was going to show any benefit. And based on that, plus the progress of the trial, they made a decision to stop the study. Dr. Sean Pokorney: Yeah. I think it's really important when we look at these decisions, that there was example when we talk about this in the editorial as well with the ISIS-2 trial, where early on in the data, ISIS-2 was a trial looking at aspirin versus placebo. And basically in that trial, when you looked early on at the events that were accumulating, there was really roughly no difference between aspirin and placebo. And ultimately, that trial became positive and was a really critical trial. And if it had been stopped at that point for futility, we wouldn't have had some really critical data. Dr. Sean Pokorney: So, it's always a challenging decision. And obviously, the decisions are trying to be made in the best interest of the patients. Here, it just shows how important this additional follow-up data is for this trial, for RAFT in particular. And ultimately, it'll be interesting to see, as you mentioned, as we add additional long-term follow-up, how that will affect the results. Dr. Ratika Parkash: Absolutely. So, we hope that our additional follow-up is of benefit to clarifying our results. The unfortunate issue, I agree, was the stopping of the study, but we do trust our DSMCs. We have them for a reason and they perform an important function. So, we have to pay attention of course, to how they see things and evaluate the... at the time. Dr. Ratika Parkash: The other thing we should keep in context is that ablation for those, that time period, is not the same as it is today. Our safety has improved. You may have noticed that there were some adverse events in the study with ablation, and we would expect it to actually be lower, but in this day and age, but at the time, contact force wasn't available. Dr. Ratika Parkash: There were some tools and techniques that we now have at our disposal, improved mapping systems and so on, that allow us to do a safer and more efficacious job. But even in the context of that, our sinus rhythm maintenance was almost 80 to 90% for patients that you wouldn't normally expect to have that much sinus rhythm. Dr. Sean Pokorney: Yeah. I think that's a really critical point. You made a lot of really important points there, actually. Obviously, the vision of the field of electrophysiology is shifting, as you mentioned. And with data from EAST-AFNET 4, we're really shifting towards earlier rhythm control, as well as additional ablation trials attest, stop AFib or stop AF. Dr. Sean Pokorney: So again, there have been several studies that have shown the benefits of earlier rhythm control, EAST-AFNET 4, I think, being obviously one of the most relevant, looking at addressing atrial fibrillation of population of patients who've been diagnosed within the last year, and showing that there was a benefit to rhythm control, although the majority of rhythm control in that study was antiarrhythmic medications. Dr. Sean Pokorney: I think in the heart failure population, the challenge with rhythm control is that we're a lot more limited in terms of the medical therapies that are available for these patients. And I think that's where ablation really plays in a more important role, because not only have you shown that it seems to be efficacious in this patient population, with a really high rate of rhythm control, but in a lot of these patients, it's often a safer alternative than antiarrhythmic therapy. Dr. Ratika Parkash: Absolutely. And we've already shown that amiodarone is ineffective in this population, in AF-CHF. So, using that drug does not seem to be, in a population that could go for an ablation, the appropriate approach. Dr. Sean Pokorney: Yeah. And as well, I think that's important. And when you look back at data from SCD-HeFT as well, there were some concerns with safety signals of amiodarone in patients with heart failure as well, from that study, again, likely related to the side effects of the medication itself. Dr. Sean Pokorney: So again, it is a complex patient population in terms of decision-making and management. And I do think, again, we talked a lot about the trial being stopped earlier than we would've ideally liked. I still think that the data that you guys produced is really important and critical and additive. Again, we're consistently seeing these modest treatment effects across multiple studies. And the fact that all the studies are pointing in the same direction is very reassuring. Dr. Ratika Parkash: Yeah. I was just going to comment on some of the points that Sean had raised, with respect to early rhythm control and the concept of atrial substrate, and how advanced atrial substrate with a negative remodeling effect in patients with heart failure or prolonged atrial fibrillation may not necessarily be in our patient's benefits to then try to intervene, and trying to get these patients early would be useful. Dr. Ratika Parkash: So in RAFT-AF, patients did not have to fail an antiarrhythmic drug in order to get into the study. So that, again, critical, very much along the lines of EAST-AFNET and EARLY-AF, which was also published, demonstrating benefit for early intervention. Dr. Carolyn Lam: Wow. Just, thank you so much, both of you. That was such a rich discussion, really, really unpacking very, very important elements of the trial, not just the trial results, but also the implications of what happens with trial conduct and execution and so on. Dr. Carolyn Lam: Again, thank you so much Ratika, for publishing this very important paper in circulation, Sean, for your beautiful editorial that put it all in context, the audience for listening today. From Greg and I, you've been listening to circulation on the run. Thank you for joining us today, and don't forget to tune in again next week. Dr. Greg Hundley: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors or of the American Heart Association. For more, please visit AHAJournals.org.
This week, please join author Ronald Goldberg, Editorialist Hertzel Gerstein, and Guest Editor Rury Holman as we discuss the article "Effects of Long-term Metformin and Lifestyle Interventions on Cardiovascular Events in the Diabetes Prevention Program and Its Outcome Study" and the editorial "Shouldn't Preventing Type 2 Diabetes Also Prevent Its Long-Term Consequences?" Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-host. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Centre and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Today. Oh, this feature discussion involves the glance of diabetes. Truly this interview, I felt like I was sitting among gurus and just learning so much about diabetes, the history and the whole topic is about long term metformin and lifestyle interventions on cardiovascular events in the Diabetes Prevention Program and its outcome study. Now, way more than that, we discussed. You have to have to listen. But okay, before that, let's summarize today's issue for our listeners. Shall we, Greg? Dr. Greg Hundley: You bet Carolyn. So the first paper that I've got to discuss today really comes to us from the world of interventional cardiology and it's led by Dr. William Fearon from Stanford University Medical Center. Well, Carolyn previous studies have shown quality of life improves after coronary artery revascularization, more so after coronary artery bypass grafting than after PCI. Now this study aimed to evaluate the impact of fractional flow reserve guidance, and current generation zotarolimus drug-eluting stents on quality of life after PCI compared with CABG. Dr. Greg Hundley: Now the study emanates from fractional flow reserve versus angiography for multi vessel evaluation or the fame three trial. And Carolyn, that's a multicenter international trial that included 1500 patients with three vessel coronary artery disease who were randomly assigned to either CABG or FFR guided PCI. Now, what did they assess? So quality of life was measured using the European Quality of life Five Dimensions. And we're going to abbreviate that EQ-5D questionnaire baseline, one, and then 12 months following the procedure. Also, Canadian cardiovascular class angina grade and working status were assessed at the same time points, and then also an additional time point in six months. And the primary objective was to compare the EQ-5D summary index at 12 months, and secondary endpoints included angina grade and work status. Dr. Carolyn Lam: Ooh, interesting Greg. So quality of life in the theme three trial. All right. So what did they find? Dr. Greg Hundley: Right, Carolyn. So the EQ-5D, so that... European Quality of life Five Dimensions summary index at 12 months did not differ between the PCI and CABG groups, but the trajectory over the 12 months at the one month time interval between PCI and CABG did differ. Now, the proportion of patients with the Canadian cardiovascular class or CCS2 or greater angina 12 months was 6.2% versus 3.1% respectively in the PCI group compared with the CABG group. Additionally, a greater percentage of younger patients, so those less than 65 years old were working at 12 months in the PCI group compared with the CABG group. So in summary, Carolyn, in the fame three trial, quality of life after fractional flow reserve guided PCI with current generation DS compared with CABG was similar in one year. And the rate of significant angina was low in both groups and not significantly different. However, the trajectory of improvement in quality of life was significantly better with PCI as was working status in those less than 65 years old. Dr. Carolyn Lam: Wow. Thanks Greg. Hey, guess what? It's time for Greg quiz. The next paper is about the Chocolate Touch Study. So, Greg, is this about, A, the benefits of eating chocolate? B, the benefits of chocolate mud baths? Or C, the benefits of a second generation drug coated balloon? Dr. Greg Hundley: So, Carolyn, I just have one question. Where in the world do we get the benefits of chocolate mud bath? I don't think that's right. I do love eating chocolate, but I am going to go with the benefits of the second generation drug coated balloon. Dr. Carolyn Lam: Yeah, yeah, yeah. I made it easy for you. All right. So first generation drug coated balloons have significantly reduced the rate of restenosis compared to balloon angioplasty alone. However, high rates of bailout stenting and dissections persist. The chocolate touch drug coated balloon is a nitinol constrained balloon designed to reduce acute vessel trauma and inhibit neointima formation and restenosis, so you were right, Greg. In today's study led by Dr. Shishehbor, from University Hospital's Harrington Heart and Vascular Institute at Cleveland, Ohio. They studied 313 patients with claudication or ischemic rest pain, and superficial femoral or popliteal disease. And randomized them one to one to the chocolate touch or Lutonix Drug Coated Balloon at 34 sites in the United States, Europe and New Zealand. The primary efficacy endpoint was drug coated balloon success defined as primary patency at 12 months. The primary safety endpoint was freedom from major adverse events at 12 months. A composite of target limb related death, major amputations, or reintervention. Both primary endpoints was assessed for non-inferiority and have met sequential superiority testing for efficacy was pre-specified. Dr. Greg Hundley: Interesting, Carolyn. So this nitinol constrained balloon designed to reduce acute vessel trauma. So, what were the results of this study? Dr. Carolyn Lam: So in this trial, the second generation chocolate touch drug coated balloon met both non-inferiority endpoints for efficacy and safety. And was more effective than the Lutonix Drug Coated Balloon at 12 months for the treatment of femoral popliteal disease. Cool, huh? Dr. Greg Hundley: Very interesting. Great summary, Carolyn. So Carolyn, my next paper comes to us from the world of preclinical science. And the impact of three dimensional chromatin topology on transcriptional dysregulation and pathogenesis in human dilated cardiomyopathy remains elusive. And so these authors led by Professor Lei Jiang from Guangdong Provincial People's Hospital, and Guangdong Academy of Medical Science, generated a compendium of 3D epigenome and transcriptome maps from 101 biobank human dilated cardiomyopathy, and non-filing heart tissues and mouse models to further interrogate the key transcription factor implicated in 3D chromatin organization, and transcriptional regulation in dilated cardiomyopathy pathogenesis. Dr. Carolyn Lam: Oh, wow. Sounds like a lot of work. What did they find, Greg? Dr. Greg Hundley: Right, Carolyn. So they found that enhancer promoter connectomes are extensively rewired in human dilated cardiomyopathy, which reside in pre accessible chromatin size and also hand one drives the rewiring of enhancer promoter connectome to induce dilated cardiomyopathy pathogenesis. Dr. Carolyn Lam: Okay, Greg. So what are the clinical implications? Dr. Greg Hundley: Right, Carolyn. So first, dilated cardiomyopathy enriched enhancer promoter loops identified in this study could be developed as novel 3D genomic biomarkers for dilated cardiomyopathy. And then second Carolyn, targeting hand one might be used as a novel approach for therapeutic intervention in patients with dilated cardiomyopathy. Dr. Carolyn Lam: Oh, nice. Greg. Well, also in today's issue, there's an On My Mind paper by Dr. Brook, entitled, “The Doctor is Out, New Tactics and Soldiers For our Losing Battle against Hypertension.” In another paper, we have Molly Klemarczyk bringing us highlights from the Circulation Family of Journals. Dr. Greg Hundley: Right, Carolyn. And also from the mailbag, there's a Research Letter from Professor Baggish, entitled, “Cardiovascular Outcomes in Collegiate Athletes, Following SARS-CoV-2 Infection: The 1-Year Follow Up From the Outcomes Registry for Cardiac Condition in Athletes.” Well, Carolyn, how about now we get onto that feature discussion and learn a little bit more about the long term metformin and lifestyle interventions on cardiovascular events in the Diabetes Prevention Program. Dr. Carolyn Lam: Hold on to your seats, everyone. Here we go. We know that lifestyle intervention and metformin have been shown to prevent diabetes. However, what is their efficacy in preventing the cardiovascular disease associated with diabetes development? Well, guess what? We're going to have data on that through today's feature paper and what a star crowd I'm talking to today. We have Dr. Ron Goldberg and he's a first end corresponding author from the University of Miami Diabetes Research Institute. We have the editorialist Dr. Hertzel Gerstein from McMaster University Population Health Research Institute. And a guest editor for this paper, Dr. Rury Holman from University of Oxford. I have to admit I'm starstruck. You gentlemen have totally defined the field. I cannot wait to learn more, but shall we start with you, Dr. Goldberg? Could you tell us a little bit more about your paper, what you did, what'd you found? Dr. Ronald Goldberg: So the background is that the Diabetes Prevention Program started in 1996 was a Diabetes Prevention Program to test the effects of intensive lifestyle intervention versus metformin, versus placebo on the prevention of diabetes in over 3000 individuals with impaired glucose tolerance, a form of prediabetes. And after demonstrating the efficacy of those interventions over about three years, we went on to do a follow up study in which the metformin group continued to receive it. Everybody got lifestyle because it worked so effectively. And we are now reporting after a further 18 years of follow up on the question of whether these interventions, now 21 years later, had any effect on cardiovascular outcomes. The background to that of course, is that people with prediabetes have a somewhat increased risk for heart disease and that rate increases as diabetes develops, particularly with severity of hyperglycemia and duration of diabetes. So, that was the study and we're now reporting on whether these interventions had a significant effect on the major cardiovascular. Dr. Carolyn Lam: Well, first Dr. Goldberg, congratulations on the foresight to get the informed consent and to plan ahead to be able to get these valuable data. But because I know this is going to be a critical point later. Could you tell us a little bit about the completeness of follow up and perhaps surveillance for outcomes before you share the results? Dr. Ronald Goldberg: Absolutely. So, 86% of the original randomized group of participants agreed to continue with a follow up study, so there was a loss at that point. And then of course, over 18 years of follow up, there's going to be a further loss. Some due to death and some due to loss to follow up. But despite that, I would say the group that entered the follow up study, we were able to maintain follow up in 85%. Dr. Carolyn Lam: Fantastic. And the results? Dr. Ronald Goldberg: The findings were that we found no significant effect of either of the two active interventions on our primary cardiovascular outcome, which was nonfatal myocardial infarction, stroke and fatal cardiovascular disease. We also had an extended outcome with more events in it, and similarly found no significant benefit or harm from either of those two intervention. Dr. Carolyn Lam: Oh, I love that paper. What a great, great, perhaps surprising conclusion that Dr. Gerstein loved the title of your editorial, you crystallize it. Shouldn't preventing type two diabetes also prevent long term consequences? So please tell us what was your thoughts when you saw this paper and how you frame it? Dr. Hertzel Gerstein: Thanks very much, Carolyn. And first of all, I was very impressed by the extensive amount of work and analysis done by Dr. Goldberg and his team. I thought that it's wonderful to see this sort of long term follow up. I've had the privilege in the past of speaking together with the DPP team on their trial and in their long term follow up. And I continue to be impressed by the extensive amounts of work and data collected and a rigor and academic value of the analysis. So, that was my very first impression and obviously it's a pleasure to write on this. I think the findings are clearly important and they both highlight the importance of long-term follow up as well as highlight the difficulties of long-term follow up in a study like this. Dr. Hertzel Gerstein: So this was a study done in a trial, originally done in a fairly young cohort of individuals who had very low risk for cardiovascular events. And over their 18 year follow up that Dr. Goldberg Ron described, the actual annual event rate for the primary outcome was 0.6% per year in that ballpark. Now, anybody... I've had the privilege as Ron Avery of doing many cardiovascular trials and we all know that we would never start a trial recruiting people with an event rate of 0.5% per year, 0.6% per year, because we would have to recruit 30,000 people and follow them for seven years in order to accrue enough events to be able to detect a clinically relevant benefit of the therapy. So because of this low event rate, the advantage was the long term follow up, the 26th year, I think it was in the end follow up. No, it was a 21 year median follow up period, because of the long follow up, you get a little bit away from the advantage of the low event rate. Dr. Hertzel Gerstein: But even then, over the course of the 21 years, there were only about 310 first cardiovascular events and most cardiovascular outcomes trials, for instance, we need close to at least a 1000, 500 to a 1000 is what we like to see. So that being said, it's perhaps not surprising that we didn't see a benefit of diabetes prevention because even if diabetes reduces the risk of a cardiovascular event by a quarter, by 25%, there would've only been a 50, 50 chance of detecting that with this particular cohort of people. Dr. Hertzel Gerstein: So I would say that the most conservative assumption is that diabetes prevention doesn't reduce the event rate by 25% or less or 30, but it's certainly... pardon me, by 25% or more, it could reduce it by 20%, 15% we would not have detected at all, or Ron would not have detected and his team would not have detected it with this thing. So I think that to me is the most important caveat in interpreting this does not mean that diabetes prevention has no effect on cardiovascular outcomes. Dr. Hertzel Gerstein: It means that diabetes prevention doesn't have a moderate or smaller effect. So, that's I think the most important message to take and as is even mentioned in the paper by Ron and the team is that there has been at least one diabetes prevention trial conducted in China many, many years ago that showed clearly that people who were randomly assigned to the diabetes prevention arm, 26 years later did have lower cardiovascular events and even death than people who were in the control arm. So, I think this adds to the story but it's clearly like everything, not the final word in this, but it certainly adds a lot of important data. Dr. Carolyn Lam: Oh, I would love to hear Dr. Goldberg's response to that. But before that, Dr. Holman, could I ask you to weigh in as well? Dr. Rury Holman: Yes. Sure. So, I agree with Hertzel that this is underpowered, but this is a question I've long wanted to see the answer to. And I congratulate Ron and his team for actually doing the work. All major studies should have long term follow up. People should be consented for life so that we can answer these questions. And Hertzel even though the power is perhaps minimal, we still need to do this analysis. Dr. Rury Holman: And if there had been a dramatic result, then we'd have all been very excited. I think one of the issues... one, if I could just bring it up, you mentioned the look ahead study in your discussion as being a negative dietary intervention. But I have a slightly different take on that. When you look at that paper in detail, what you see is that the people in the usual care group forgot quite a lot more risk factor reduction medications, and that's because their usual care physicians spotted the fact that their risk factor levels were higher than in the intensive care group, of course it was blinded at that point. But there's a whole point here is, in your paper you show an increase in the statin proportion, which is higher in the placebo group compared with the metformin and your intensive lifestyle, significantly so for the lifestyle one. So I'm just wondering whether even the low power was further blunted by the drop in effects of these other medications. Dr. Ronald Goldberg: Thanks very much for those comments guys, I think they're spot on. Let me first respond Hertzel with my thoughts on this, and then go over to your point, Rury. I think it's really interesting to look back over time and realize how much medical management has changed. And that goes right to your point, Rury, that doing a clinical trial like this where the primary care physicians are informed about what we're doing, what... communicated with on a regular basis, particularly when their patients develop diabetes, it just heightens the entire level of medical management. And I think you're absolutely right, but it's interesting to see what's happened to cardiovascular disease over the last 25 years, both in the general population and in the prediabetic population, the risk of cardiovascular disease has gone down. And then on top of that, we've got this very intensive cardio prevention intervention by primary care physicians, with high rates of statin usage, high rates of any hypertensive treatment, even the placebo group to your question, really lost weight. Dr. Ronald Goldberg: And they knew full well what was... and this was a very hands on type of study where our participants were really followed now for all these years, really became integrated with the research team. And so everybody knew what everybody else was doing. And so I'm sure the placebo effect was very strong, but I think nevertheless... Oh, and the last point I wanted to make was of course, the severity of the diabetes, even though 60% are developed diabetes, the severity of the diabetes was relatively mild. Even in those who developed diabetes, we know their average A1C was only about 6.7. And so I think that has a lot to do with blunting the acceleration effect of diabetes on cardiovascular disease. So, I think all of these factors contributed together to produce a negative result. But I think an important message, nevertheless. Dr. Hertzel Gerstein: I can highlight that point, that Ron was saying is that if diabetes prevention is going to prevent cardiovascular outcomes, it's going to do that because of a difference in glycemic exposure. The diabetes is by definition a disease of an elevated blood sugar. So if diabetes prevention prevents cardio, it means that the blood sugar's going to be lower than it would otherwise be. So if there's very little difference over the long term follow up in blood sugar because of co-intervention and therapy of all the treatment groups, then that would eliminate a lot of the benefits of diabetes prevention, because these are patients who are in this trial, who are being scrutinized even more than they would be if they were out there free range without being involved in any follow up. So, that's a spot on point. Rury, you wanted to comment. Dr. Rury Holman: Yeah. So, Hertzel just to expand on that. Obviously the glycemic impact on macrovascular disease is relatively modest compared to the impact on microvascular disease, which of course is what we all saw originally with type 2 diabetes. In fact, in KPDS35, when we looked or calculated what 1% reduction in A1C would do, it would only reduce stroke or MI by about 12 to 14%. So it's quite a shallow slope if you like. And your point is spot on is if that glucose levels are kept low by good treatment and good management role tell us about the great team they have. Then there was no room for a glycemic impact in this particular study. It's another question, whether you think metformin acts by different mechanisms to reduce cardiovascular disease, that's another question I had for Ron that he might like to address, is if there was a magic effect of metformin, why didn't we see that? Dr. Ronald Goldberg: And that's a really interesting question, Rury, because you may be aware that we published a paper a few years ago on our assessment of coronary calcification in a subgroup, in about 60% of the population who agreed to do this and who were eligible. And interestingly found that metformin did was accompanied by a reduction in the prevalence of coronary calcium in men, not women. Dr. Ron Goldberg: And the effect was actually when we did subgroup analysis, we found it was particularly strong in young men. And actually that gave us some sense of optimism that we might see something when we came to actual events. And of course, as you all know, metformin has beneficial effects on several cardiovascular risk factors. And so the question is whether there is some effect of metformin that might yet be identified, a coronary calcium after all is a surrogate of events and may take time, or it may be that... And we are really interested in the idea that both prediabetes and diabetes are heterogeneous. There's more and more interest in looking at subgroups of individuals who may be more predisposed. And it may be that metformin might have beneficial effects in some of those subgroups. Dr. Hertzel Gerstein: But also remember on the other hand, there was a lot of co-intervention with metformin in all groups after the trial was over. So all groups were offered metformin, et cetera. So even if metformin had an effect, it could have easily been washed out by the exposure of all the other groups to metformin during follow up. But Ron, you also touched on both the hope and the frustration too, because if we start thinking about subgroups, we can always think of subgroups. Yeah. But then the problem with subgroups is you have a study, let's say you have a cohort study with 7,000 or 10,000 people and it followed for five years and, oh, well the effect isn't in all 10,000, it's only in 20% of them. So now you have a study of 2000 people, that's not enough to detect an effect in a subgroup. Dr. Hertzel Gerstein: So, subgroups just eat away at power in an exponential, not a linear way, so that you just rapidly lose any ability to detect anything. And so, yes, this is going to work in people with these three snips on this gene, in this subpopulation. Good luck, that's the difficulty and the challenge of... We need to find sometimes better or more efficient ways of identifying outcome protective therapies, because we can't keep drilling into some groups because we just don't have the resources to find it really. I don't know what other people feel about that, but. Dr. Carolyn Lam: I'm personally so enjoying this conversation as I know the audience is and we covered a lot. I'm sure everyone wants to pick up the paper and the editorial. Now, we talked about being underpowered for the number of studies. We talked about profitable dilution of things like statins, antihypertensive agents, even the crossover of potential treatment in the placebo arm and so on. And then we started talking about, or is it the how you got there and the drug that was used. And here, please don't shoot me, but I just know I have the answers on behalf of everyone else's thinking it. What do you say of people who go, "Well, it's because it's metformin. What if it was an SGLT2 inhibitor? What if it was a GLP-1 receptor agonist?" And as you know, a lot of people say those would in spite of the effect on glucose. Dr. Hertzel Gerstein: I can quickly jump in. It's very clear. We've learned this in the last 10 years, is that there are glucose lowering drugs and there are glucose lowering drugs with benefits. And the GLP-1 receptor agonist and the SGLT2 inhibitors are glucose lowering drugs with benefits. They lower glucose, but they seem to have a separate cardioprotective effect. And with the SGLT2 inhibitors that cardioprotective effect does not seem to be related to the glucose lowering. There are a few meta regression analyses that suggest that with the GLP-1 receptor agonist, part of the cardioprotective effect is related to glucose lowering and part is not. And clearly mediation analysis with some of the trials have shown the same thing with the GLP-1 receptor agonist, not really with the SGLT2 inhibitors. So, maybe, that's my spin on this. Dr. Carolyn Lam: Dr. Holman. Dr. Rury Holman: Yeah. I was going to echo what Hertzel said in that regard, these other agents do have multiple effects. They change weight, they change blood pressure. And so other risk factors are brought into play other than glucose lowerings. We've already agreed, glucose lowering impact on cardiovascular disease is quite modest. I'd rather have it than not, but it wouldn't be my primary way to treat cardiovascular disease. And coming back to Ron's study, which is crucial today, the issue here is whether we could untangle an impact particularly of metformin, which has been foundation drug for type 2 diabetes for so long. Dr. Rury Holman: But clearly within the dataset we have here, underpowered it is. There are no clear messages in that respect, which is disappointing, but it doesn't mean that there isn't an effect. With longer follow up, with more data than you might see it. When the study... I'm coming for you Hertzel, was stopped for futility then the hazard ratio has changed, that often the way, not for the right way, but it's often what happens when you stop studies. I wondered if you wanted to comment on that aspect, because I know it's something that you've talked a lot about. Dr. Carolyn Lam: Dr. Gerstein. Did you want to? Dr. Hertzel Gerstein: I agree with what Rury said. I think the point you're making Rury goes back to power, and the ability to have enough people and enough events to detect and effect and that's clearly true, so... Dr. Carolyn Lam: Well, I hate to be the one to break the party up, but we have gone over time and intentionally so, there's just so much learning here. But Dr. Goldberg, could I give you the last say please? What do you think is the important clinical take home message of your paper? Dr. Ron Goldberg: Well, I think that the fact that we demonstrated that our study has been able to maintain really low levels of cardiovascular risk factors, low levels of A1C, even though that likely contributed to the negative finding still leaves the physician where the recognition that it is important to identify individuals with prediabetes to Institute Diabetes Prevention Programs, because I think it's entirely possible as I said earlier, and we've begun to identify them, subgroups of individuals who do progress more rapidly and who do warrant a more effective treatment, which would come from an early intervention program. Dr. Carolyn Lam: Wow. Thank you so, so much for that. Thank you so much. All three gentlemen for this amazing discussion. Well, audience, you heard it right here on Circulation on the Run from Greg and I thank you for joining us today and don't forget to tune in again next week. Speaker 6: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Sanjiv Shah, Editorialist Evangelos Michelakis, and Associate Editor Justin Ezekowitz as they discuss the article "Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure" and Editorial "Atrial Shunt Devices in Patients with Heart Failure and Preserved or Mildly Reduced Ejection Fraction and the Pulmonary Circulation: Promises and Concerns." Dr. Carolyn Lam: Welcome to Circulation On The Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from The National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health, in Richmond, Virginia. Dr. Carolyn Lam: Greg, I love today's featured article. It's all about heart failure with mildly reduced and preserved ejection fraction, talking about device therapy and the response to therapeutic atrial shunt device. Now, this is a very interesting discussion of how specifically selecting patients based on latent pulmonary vascular disease may hold some answers, but we're going to keep everyone hanging here. You've got to, got to listen to the discussion. But first, we'd like to tell you about some of the papers in today's issue. And I think Greg, you've got one to start us with, right? Dr. Greg Hundley: Absolutely. Carolyn, thank you so much. Well, this first paper comes from Dr. Eliot Peyster from the University of Pennsylvania. And Carolyn, the aim of this study was to leverage computational methods for analyzing digital pathology images from routine endomyocardial biopsies, to develop a precision medicine tool for predicting cardiac allograft vasculopathy, years before overt clinical presentation. Dr. Carolyn Lam: Ooh, interesting. Again, precision tools. So what did they find? Dr. Greg Hundley: Right, Carolyn. So there was a clinical predictive model that achieved modest performance on the independent test set, with area under the receiver operating curve of 0.7. But interestingly, a histopath- predictive model for predicting cardiac allograft rejection achieved good performance, with an area under the receiver operating curve of 0.8. Most importantly, however, a model, incorporating both clinical and histopathologic features, achieved excellent predictive performance, with an area under the receiver operating curve of 0.93. Dr. Greg Hundley: So in summary, Carolyn, these authors found that prediction of future cardiac allograft vasculopathy development is greatly improved by incorporation of computationally extracted histologic features. Their results suggest morphologic details, contained within regularly obtained biopsy tissue, have the potential to enhance precision and personalization of treatment plans for post heart transplant patients. Dr. Carolyn Lam: Aw, that's cool. Makes so much sense, but yet so novel. Thanks. Dr. Carolyn Lam: Well, for the paper I want to talk about, we are going to talk about dapagliflozin. Now we know the SGLT-2 inhibitor, dapagliflozin, improved heart failure and kidney outcomes in patients with Type two diabetes with or at high risk for cardiovascular disease, in the DECLARE–TIMI 58 trial. In the current paper, authors, led by Dr. Wiviott from the TIMI study group, aimed to analyze the efficacy and safety of dapagliflozin stratified, according to baseline systolic blood pressure. Dr. Greg Hundley: Ah, so an interesting question, since SGLT-2 inhibitors are known to reduce blood pressure. And given the concerns regarding the safety of SGLT-2 inhibitors, in patients with low to normal systolic blood pressure. So Carolyn, what did they find? Dr. Carolyn Lam: Nicely put Greg. So in patients with type two diabetes with, or at high risk of, atherosclerotic cardiovascular disease, dapagliflozin reduced the risk for heart failure hospitalizations and renal outcomes, regardless of baseline systolic blood pressure, with no difference in benefit for reduction in heart failure or renal outcomes, among patients with blood pressure from the normal range, all the way to severe hypertension. Moreover, there appeared to be no difference in adverse events of volume depletion, acute kidney injury, or amputations, across the levels of baseline blood pressure. So these results indicate that dapagliflozin provides important cardiorenal benefits in patients with Type two diabetes at high risk, the independent of baseline blood pressure. Dr. Greg Hundley: Oh, very nice, Carolyn. Well, my next paper comes to us from the world of preclinical science, and it's from professor Jeffrey Towbin and colleagues, at Le Bonheur Children's Hospital. So Carolyn, as we know, arrhythmogenic cardiomyopathy is an inherited genetic disorder of desmosomal dysfunction, and plakophilin-2 has been reported to be the most common disease causing gene when mutation is positive. Now in the early concealed phase, the arrhythmogenic cardiomyopathy heart is at high risk of sudden cardiac death before cardiac remodeling occurs, due to mis-targeted ion channels and altered calcium handling. However, the results of pathogenic plakophilin-2 variants on myocyte contraction in arrhythmogenic cardiomyopathy pathogenesis, really remains unknown. So Carolyn, these authors studied the outcomes of a human truncating variant of plakophilin-2 on myocyte contraction, using a novel knock-in mouse model, as well as evaluation of human subjects. Dr. Carolyn Lam: Oh, interesting. So what were the results from this plakophilin-2 knock-in mouse model? Dr. Greg Hundley: Right, Carolyn. So serial echocardiography, a plakophilin-2 heterozygous mice revealed progressive failure of the right ventricle, but not the left ventricle, in animals older than three months of age. Now next, adrenergic stimulation enhanced the susceptibility of plakophilin-2 heterozygous hearts to tachyarrhythmia and sudden cardiac death. Contractility assessment of isolated myocytes demonstrated progressively reduced plakophilin-2 heterozygous RV cardiomyocyte function, consistent with right ventricular failure, measured by echocardiography. Dr. Greg Hundley: And the next, Western blotting of plakophilin-2 right ventricular homogenates revealed a 40% decrease in actin. In contrast, plakophilin-2 heterozygous left ventricular myocytes had normal contraction and actin expression. Dr. Greg Hundley: And finally, Carolyn, Western blotting of cardiac biopsies revealed actin expression was 40% decreased in the right ventricles of end stage arrhythmogenic cardiomyopathy patients. So in conclusion, Carolyn, during the early concealed phase of arrhythmogenic cardiomyopathy, reduced actin expression drives loss of RV myocyte contraction, and that contributes to progressive RV dysfunction. Dr. Carolyn Lam: Wow. Thanks, Greg. Well, also in today's issue, there's an exchange of letters among Drs. Whitman, Ibrahim, and Løfgren, regarding physics at the heart of the matter, referring to the article, “Anterior–Lateral Versus Anterior–Posterior Electrode Position for Cardioverting Atrial Fibrillation.” Dr. Greg Hundley: Right Carolyn. And also in the mail bag, there's an On My Mind piece, from Professor Taegtmeyer, entitled, “The 2022 Beijing Winter Olympics, The Spotlight On Cardiac Metabolism.” Dr. Greg Hundley: Well, how about we get onto that feature article, and learn a little bit more about atrial shunts, and how they may be helpful in heart failure with preserved ejection fraction? Dr. Carolyn Lam: Ooh, can't wait. Dr. Greg Hundley: Well, listeners, we have a very interesting feature discussion today related to hemodynamics pertaining to interatrial shunt devices, in those with and without pulmonary hypertension. And we have, gosh, a repertoire of speakers today. We have Dr. Sanjiv Shah, from Northwestern University in Chicago, Dr. Evangelos Michelakis, from Edmonton Alberta, and our own associate editor, Dr. Justin Ezekowitz, also from Edmonton Alberta. Dr. Greg Hundley: Well, Sanjiv, we're going to start with you. Describe for us, some of the background pertaining to your study, and what was the hypothesis that you wanted to address? Dr. Sanjiv Shah: Great. Thanks, Greg. Thanks for having me today. Well, the background of our study is that, it was a subgroup analysis, or a secondary analysis, of the REDUCE LAP-HF II trial. Now this trial has been in the making for over 12 years, almost 13 years. It started out as an idea that was David Celermajer. David is a pediatric cardiologist in Australia, who had this idea that, in mitral stenosis patients, it's well known that, if there's a concomitant secundum ASD, a congenital secundum ASD, in these patients with mitral stenosis do better. They have a way to unload the left atrium, and distribute that blood to the systemic veins and the right atrium, the right side of the heart. And so could this be helpful in quote, diastolic, heart failure or HFpEF? Dr. Sanjiv Shah: And so, I started working with him about 12 years ago. This started out as a concept. It was studied in animal models, and then in humans, in open label studies, and then, in a first randomized controlled trial. Where we showed, that an intraatrial shunt device, an iatrogenic ASD, so to speak, put in humans with heart failure with risk preserved EF, results in a lowering of exercise pulmonary capillary wedge pressure. And so based on that data, we designed a pivotal trial, a Phase III trial, the largest trial of its kind, of heart failure with preserved and mildly reduced ejection fraction, to see if interatrial shunt device would improve outcomes. And we published that trial earlier this year in the Lancet. Unfortunately, it was a totally neutral trial. And when you have a neutral trial in any condition, but as we see often in HFpEF, the question is, was it neutral overall? Or was there a subgroup that benefited? And what we found in that trial was that, there were three predefined subgroups that came out that seemed like there was a difference. Dr. Sanjiv Shah: First, there was a sex difference. Women did better. Men did worse with the device. Then, there was right atrial volume. Those with bigger right atrial volumes did worse. If you had a smaller right atrial volume, you did better. But the most significant interaction and subgroup was exercise pulmonary artery systolic pressure. Dr. Sanjiv Shah: If the pulmonary artery systolic pressure was greater than 70 at 20 Watts of exercise, so just with a little bit of exercise, those patients did worse. And if PA pressure stayed low, the patients did better. And so we sought to further explore this to say, "Okay, what's exactly going on?" In a post hoc analysis, what's going on with the pulmonary vasculature during exercise, and how does that differentiate how patients potentially respond to the device? And that's what we hope to figure out. Dr. Sanjiv Shah: We hypothesize, that if exercise pulmonary vasculature resistance is lower, then the shunt can actually work, and blood can flow from the left to the right, into the lungs, and the right heart doesn't get too overloaded. And we know, that the normal response of the pulmonary vasculature is to vasodilate with exercise. And so, if patients had retained that response, the ability to do that, that they may benefit. And so, we sought to figure that out with this subgroup analysis. Dr. Greg Hundley: Sanjiv, it sounds like a really elegant, well thought out hypothesis. So what was your study design? And describe your study population. Dr. Sanjiv Shah: Yeah. This was a randomized controlled trial. And so this was 626 patients enrolled at 89 centers across the world. And it was really, heart failure with mildly reduced, so an EF of greater than 40, or preserved EF, and 93% of them had HFpEF. And what was unique about this trial is that we, this is the first trial really, that confirmed that these patients actually had heart failure, with mildly reduced or preserved ejection fraction. Most trials say, well, you have to have an elevated BNP, and you have to have some sign of structural heart disease, and maybe, a history of heart failure hospitalization. In this trial, every single patient had to undergo rigorous noninvasive echocardiography. And then, on top of that, they had to undergo exercise invasive hemodynamic testing. And people thought that it wasn't possible for 626 patients, but we did it. And every single patient had had an exercise pulmonary capillary wedge pressure greater than, or equal to, 25. And so this really was HFpEF. So it's a randomized trial. Dr. Sanjiv Shah: And then, beyond that, we did a subgroup analysis. So we looked on various subgroups, focusing on exercise PVR, and we really looked to see the effect on three outcomes. Number one, a hierarchical endpoint, a combination of cardiovascular death, ischemic nonfatal stroke, recurrent heart failure hospitalizations, and the KCCQ. And then the other two outcomes were just the individual recurrent heart failure hospitalizations, and the KCCQ. We looked at all of these, and tried to figure out if there are certain subgroups that benefit. Dr. Greg Hundley: Great detail. So Sanjiv, what did you find? Dr. Sanjiv Shah: Well, we found that, there's this group of patients, that during exercise, the pulmonary vascular resistance at peak exercise stays above 1.74 Wood units. Now that seems like an arbitrary number, but in fact, in older individuals that are healthy, when you exercise them, the PVR upper limit, the exercise PVR upper limit, is about 1.8. So we're right about the upper limit of where the PVR should be. And if it was above that, the patients actually did worse with the shunt device. They had a lot more heart failure hospitalizations. Their KCCQ got worse, didn't benefit. And if they were below that threshold, meaning they were, sort of compliant pulmonary vasculature, and it stayed compliant, or they vasodilated effectively with exercise, then they benefited from the device. And what we call this concept of exercise-induced pulmonary vasoconstriction, or inability to vasodilate, is latent pulmonary vascular disease. Dr. Sanjiv Shah: And so, if you have that latent pulmonary vascular disease, your win ratio is 0.6. That means you do worse. And if you don't have this pulmonary, this latent pulmonary vascular disease, your win ratio is 1.31. And that means, you do better with the device. And we saw very similar findings with the KCCQ. We saw similar findings with the recurrent heart failure hospitalizations. Dr. Sanjiv Shah: And the final thing is, we found that, we looked at various other subgroups, and it turned out that if there was no latent pulmonary vascular disease and no history of pacemaker, which we found was kind of associated with sex and right atrial volume, those patients, for about 50% of the group, actually did the best. And that was what we called, the responder subgroup. Dr. Greg Hundley: Thank you, Sanjiv. Well, listeners, we're going to turn now to our associate editor, Justin Ezekowitz. And Justin, you have many papers come across your desk. What attracted you to this particular manuscript? Dr. Justin Ezekowitz: So Greg, this paper kind of stood out for a number of different reasons, as I sent you. You're to be congratulated for a variety of reasons. But the number one is, pursuing the data from a neutral trial overall, to understand who might benefit and who might be harmed from a pretty novel device and way to treat patients in such a scale, that's not being done like this before. So it stands out by just the magnitude of number of right heart catheterizations, number of patients enrolled, number of procedures done. And all of those things really lead to us to be able to understand the area much better than I think we can in a human population. Dr. Justin Ezekowitz: Where this sits with other devices that are very similar, is hard to really know, if all devices are going to be the same or different, but your population is quite unique is if they're not all end stage, but they're sick enough to get into your trials. So there's this population we treat actively. And I wondered if you could touch on that continuous nature. And so for readers, there's this beautiful figure, which shows a continuous nature of exercise PVR. And I wonder if you could touch on that. Is this mid group, the group that we should target for our future therapies like this, or this needs further study? Dr. Sanjiv Shah: Well, I think it needs further study. I think the listeners should be aware that this is a post hoc analysis. We did pre-specify exercise PA pressure. This is one trial. But it makes a lot of sense, pathophysiologically. What we're doing here is we're shunting this excessive LA, overloaded LA, shunting the blood from the LA to the RA and into the pulmonary vasculature. Well, if that pulmonary vasculature can't accept that increased flow, the patient's not going to do well. And how can we simulate that? Well, we can simulate it with exercise. As the patient's pedaling on the bike, on the cath lab table, there's increasing blood flow to the pulmonary vasculature, and we're seeing what happens with the pulmonary vasculature. Does it vasodilate, does it not? And so, I think that's why we were excited about this finding. Dr. Sanjiv Shah: I do think that, there are at least seven other companies making shunt devices, interatrial shunt devices or therapies. And I do think, they need to pay attention to this and really look at this. Not all trials are doing exercise and basic hemodynamics, that needs to be done, I think. So it'll be really interesting to see. Dr. Sanjiv Shah: Now, one thing I will say is that, and I've written about this, this is a really interesting trial. Because the BNPs were lower, and so you would think, okay, these are patients that are less sick. And yet, their heart failure hospitalization rate was at least one and a half times higher than pharma Phase III trials. KCCQ was way lower, like 30 points lower. So there are these patients out there that are really sick, and they're the ones that I think, are where their life, their sort of quality of life, their outcomes, are being driven by the HFpEF. And that's what we found in this trial. Dr. Greg Hundley: Very nice. Well, listeners, let's turn now to our editorialist, Dr. Evangelos Michelakis. And Evangelos, two questions. How do we put the results of this substudy, really in the context of the main trial? And then secondly, do you have any, with your expertise in endothelial function, and understanding the mechanisms of pulmonary hypertension, can you describe what you think might be operative as a mechanism here, and why Sanjiv observed these positive results in some patients? Dr. Evangelos Michelakis: Thank you. So the first point is that, I have to also repeat, that it was a remarkable achievement to do all this right heart catheterization on a treadmill in the cath lab. It's a very complex procedure. And it is, they have to be congratulated, the authors, for actually doing this. There is no question that, like Sanjiv said, ongoing trials for future trials will need to include the hemodynamics in the trials, before and after the procedure. Dr. Evangelos Michelakis: So another important thing is that, the authors brought up this, they called it latent pulmonary hypertension, we could call it latent pulmonary hypertension, or probably, early pulmonary hypertension, as an entity. Now that entity, it's newer in the heart failure field. It's not that old in the PIH, the pulmonary interior hypertension field, since it used to be in the guidelines for this disease, that exercise pulmonary hypertension was a diagnostic criterion for that. Because the idea is that, exercise pulmonary hypertension reflects early pulmonary hypertension. So you needed to intervene with therapies early. Dr. Evangelos Michelakis: Now, I'm not sure that this is a fact. But it is very likely that these patients, in Sanjiv's trial, that had the early, that had the sort of enhanced response with exercise, did have at least, endothelial dysfunction in the pulmonary arteries. Not only because this population has a number of endothelial risk factors, diabetes, smoking, you name it. But also, there are newer problems like SNPs polymorphism mutations, that will recognize more into the pulmonary arterial hypertension field, to be more unique to the pulmonary circulation. Dr. Evangelos Michelakis: But the reason I say that is that, the reason that you dilate with exercise, is mostly because of your pulmonary arterial endothelial cells, secreting vasodilatory factors. And also, allowing previously closed capillaries to open up with increased flow. However, the problem is that, if you have pulmonary arterial endothelial cells in vitro, and you expose them to high flow, like in this case, you can actually change their identity. Turn them into cells that are not endothelial cells anymore, are proliferative pro-inflammatory, and they can actually cause structural pulmonary circulation damage. Dr. Evangelos Michelakis: Also, there are animal models and people working in PAH and ASD, where they've shown that, if you have, if you're given endothelial toxin in animals, and then, you do an aortocaval shunt, then you get really severe pulmonary hypertension with structural disease, that is not even reversible if you remove the shunt. Dr. Evangelos Michelakis: So from this trial, the conclusion that patients with pulmonary hypertension should not get the device, is very clear. And probably, the ones with exercise pulmonary hypertension. My theoretical concern is, for those that don't have exercise pulmonary hypertension, or those that do have it, could they get worse after a number of years, and have structural pulmonary vascular disease? And unfortunately, we didn't have a follow up right heart catheterization to prove that, whether this is right or wrong. Which is a thing, is the most important thing to do in the future. So mimic the protocol for this trial from now on, but also add a follow up right heart catheterization, perhaps not just in a year, but longer. In other words, enough time to allow the structural pulmonary remodeling get established, but also, affect the right ventricle, these things don't. So maybe in a few years. It's a very demanding thing for these protocols, but I think, that's what needs to be done before we say this device can actually be beneficial for those patients, or for some patients, or not hurt others. Dr. Greg Hundley: Very nice. And so, a great segue, Evangelos, into what we think the next studies may need to be performed in this particular sphere of research. Dr. Greg Hundley: So Sanjiv, in just 30 seconds, could you share your thoughts first, and then we'll circulate back to Justin, and then finish up with Evangelos. Sanjiv? Dr. Sanjiv Shah: Yeah. I think the key thing is, to do a confirmatory trial. And that's what we're aiming for, is to do a confirmatory randomized sham-controlled trial, but focus in on these patients with an exercise peak PVR of less than 1.75, around there. And I think, that'll help answer the question. The Qp/Qs we get with this device is 1.2 to 1.3. So I don't think it's a high flow. And we actually have open label studies, where we've gone out to three years, with repeat invasive hemodynamic testing, echocardiograms, and we've had patients who've been implanted for seven years. We're not seeing, at least at that point, any sort of worsening of pulmonary vascular disease, or RV function, or anything like that. And so, it remains to be seen. Dr. Sanjiv Shah: The last thing I'll say, which I think is provocative, in the field of HFpEF, all pulmonary vasodilator drugs have failed. And though, we only measure pulmonary vascular resistance at rest. And what we saw in this trial, is that some patients have a high PVR and it comes down. Some people have a PVR that stays low, and is low and stays low. Some people have a low PVR and it goes up. You know? So I think what we need to think about in the field of PH‐HFpEF, is more exercise genotyping, to determine what's the dynamic exercise PVR? And maybe, those with exercise elevation of pulmonary vascular resistance are the ones that respond to pulmonary vasodilators. So that's another thing that I think we can think about taking away from this trial. Dr. Greg Hundley: Thank you, Sanjiv. Justin. Dr. Justin Ezekowitz: Yeah. So my thoughts are mimicking Sanjiv's. But one of the things that we desperately need is, ways in which we can noninvasively assess the exercise PVR, so that we can think about the large scale interventions that might come down the road, if interventions such as this work well. Because the noninvasive scans will really help us look at broader populations. Those are, that don't make it into trials, and those that aren't traditionally in our studies of HFpEF. So I think, that's another area where we can really grow the field, and then, grow our knowledge. Dr. Greg Hundley: Very nice. And Evangelos. Dr. Evangelos Michelakis: So, yes. Of course, like everybody said, we need trials that will have a follow up right heart catheterization, at least address, if not both, like the investigators did. But because the big question is, are these patients having an earlier stage pulmonary hypertension or not? These patients that the authors called, latent pulmonary hypertension, we need to phenotype more their endothelial cells, or their disease. And in the absence of biopsies, the only way we could do that, is perhaps, with molecular imaging, or at least, in some small populations. Or with analyzing pulmonary arterial endothelial cells in the blood, and their molecular phenotype, to see if they are a distinct group, which I suspect they may be. So further genotyping of this exercise induced pulmonary hypertension in this population, will be important as well. Dr. Greg Hundley: Thank you. Well, listeners, we've had a great discussion today, from Dr. Sanjiv Shah, from Northwestern University in Chicago, our editorialist, Dr. Evangelos Michelakis, from Edmonton, Alberta, and our own associate editor, Dr. Justin Ezekowitz from Edmonton, who brought us this study, demonstrating that in patients with heart failure and preserved ejection fraction, or heart failure and mildly reduced ejection fraction, the presence of pulmonary vascular disease, uncovered by invasive hemodynamic exercise testing, identifies patients who may worsen with atrial shunt therapy. Whereas, those without pulmonary vascular disease may, at least in the short term, benefit. And of course, as Evangelos has pointed out, the long term findings really warrant further study. Dr. Greg Hundley: Well listeners, on behalf of Carolyn and myself, we want to wish you a great week, and we will catch you next week on the Run. Dr. Greg Hundley: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors, or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join Guest Host Mercedes Carnethon and Author Brendon Neuen as they discuss the article "Sodium-Glucose Cotransporter 2 Inhibitors and Risk of Hyperkalemia in People With Type 2 Diabetes: A Meta-Analysis of Individual Participant Data from Randomized, Controlled Trials." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, this week's feature paper is on one of my favorite topics, SGLT2 inhibitors. And this time, looking at their association with the risk of hyperkalemia in people with type-two diabetes. Now this is something we've all been waiting to look at. It's a meta-analysis of individual participant data from randomized controlled trials, so a very important, clinically applicable discussion coming right up. But first, I'm actually going to talk to you about text messages. Dr. Greg Hundley: Wow, Carolyn. I can't wait to hear about this article. Dr. Carolyn Lam: Well, specifically the TEXTMEDS randomized clinical trial, which is our first paper today. It is a trial that examined the effectiveness of text-message delivered cardiac education and support on medication adherence following an acute coronary syndrome. Dr. Carolyn Lam: This is from Dr. Clara Chow from University of Sydney and her colleagues, who performed a single blind multi-center randomized controlled trial of post-ACS patients across 18 rural and urban centers and three time zones in Australia. The control group received usual care, and the intervention group additionally received multiple motivational and supportive weekly text messages on medications, and healthy lifestyle, with the opportunity for two-way communication. Dr. Greg Hundley: Wow, Carolyn. So text messaging to facilitate medication adherence. I can't wait to hear. So what did they find? Dr. Carolyn Lam: I think the design, it's such a neat study. However, the study found no significant impact on the primary outcome of medication adherence at six and 12 months, nor on LDL cholesterol or blood pressure. Dr. Carolyn Lam: However, intervention participants were more likely to achieve a normal body mass index and to eat guideline-recommended servings of fruit and vegetables. Qualitative analysis demonstrated a high level of acceptability, utility in being a unified source of information, high program engagement, and emotional support, especially during times of uncertainty. Dr. Greg Hundley: Interesting, Carolyn. Sounds like an impact on diet, so what did we learn from this study? Dr. Carolyn Lam: Well, customized and personalized text message-based prevention programs are indeed a scalable and low-cost means of delivering consistent education and support to patients following hospitalization for ACS. So this study shows it's feasible. The lack of impact, however, on medical adherence, though with better adherence to healthy lifestyle practices, suggests that maybe external factors, such as cost, may strongly influence medical adherence. These need to be addressed, in addition to education programs, to improve medical adherence. But all of this is discussed in a beautiful editorial entitled, "Opportunities and Challenges of Mobile Health Tools to Promote Health Behaviors" by Drs. Sharma and Avram. Dr. Greg Hundley: Very nice. Carolyn, what a great summary. Well, my paper comes to us from Professor Mario Delmar from New York University School of Medicine, and Carolyn, exercise training as well as catecholaminergic stimulation increases the incidence of arrhythmic events in patients affected with arrhythmogenic right ventricular cardiomyopathy or ARVC, and this correlates with plakophilin-2 mutations. Now, Carolyn, separate data show that reduced abundance of plakophilin-2 leads to dysregulation of intracellular calcium homeostasis, and Carolyn, these authors studied the relation between exercise and or catecholaminergic stimulation, intracellular calcium homeostasis, and arrhythmogenesis in plakophilin-2 deficient murine hearts. Dr. Carolyn Lam: Ooh. So what were the effects? Dr. Greg Hundley: Right, Carolyn. For training, the mice underwent 75 minutes of treadmill running once per day, five days each week, for six weeks. And the authors observed that exercise disproportionately affected calcium intracellular homeostasis in plakifilin-2 deficient hearts, in a manner facilitated by stimulation of intracellular, beta-adrenergic receptors or hyper-phosphorylation of phospholamban. Dr. Greg Hundley: Now these cellular changes created a pro-arrhythmogenic state that can be mitigated by plakophilin receptor blockade. Additionally, Carolyn, these authors' data unveiled an arrhythmogenic mechanism for exercise-induced or catecholaminergic life-threatening arrhythmias in the setting of a deficit in plakophilin-2. They suggest that membrane-permeable beta blockers are potentially more efficient for ARVC patients. Dr. Greg Hundley: And also they highlight the potential for ryanodine-receptor channel blockers as treatment for the control of heart rhythm in this population at risk, and propose that plakophilin dependent and phospholamban-dependent, ARVC-related arrhythmias have a common mechanism. Dr. Carolyn Lam: Wow, thanks again, Greg. That was really, really a nice explanation. Well, for this next original paper, it looks at the question of the association between major bleeding and non-major clinically relevant bleeding, with subsequent mortality in hospitalized patients, and authors did this by exploring this relationship in the MAGELLAN and MARINER trials of extended thrombo-prophylaxis in hospitalized medical patients. Dr. Greg Hundley: Wow. Carolyn. I can't quite remember, and maybe for our listeners, remind us of the design of the MAGELLAN and the MARINER trials. Dr. Carolyn Lam: These trials evaluated, whether rivaroxaban compared with enoxaparin or placebo, could prevent venous thromboembolism without increased bleeding. The authors, led by Dr. Spyropoulos from the Feinstein Institute of Medical Research in New York, hypothesized that patients with major bleeding, but not those with non-major clinically relevant bleeding, would be at an increased risk of all-cause mortality. So Greg, would you like to guess what they found? Dr. Greg Hundley: Oh, Carolyn, you've put me on the spot here. I'm not sure. Dr. Carolyn Lam: Maybe just, did the authors get it right or wrong? Just.... Dr. Greg Hundley: I'm saying, they got it right. Dr. Carolyn Lam: Oh, always clever. They found that compared to patients with no bleeding, the risk of all-cause mortality for patient with non-major clinically relevant bleeding was not increased in MARINER, but was increased in MAGELLAN. Major bleeding, however, was associated with a higher incidence of all-cause mortality in both studies, while trivial bleeding was not associated with mortality in either study. These results really inform the risk benefit calculus of extended thromboprophylaxis in medically ill patients. Dr. Greg Hundley: Wow. Carolyn, great presentation. We've got some other articles in this issue. And let me tell you about two that I have. First is a Research Letter from Professor Frankel entitled "Trends in Opioid Use after Cardiac-Implantable Electronic Device Procedures in the United States, between the years of 2004 and 2020." And Tracy Hampton, from the National Association of Science Writers, presents some very recent news in the world of cardiology. Dr. Carolyn Lam: Nice. Well, there's an exchange of letters as well between Drs. Yang and Nagareddy regarding the article "Retention of NLP3 Inflammasome-Primed Neutrophils in the Bone Marrow is Essential for Myocardial Infarction-Induced Granulopoiesis." And finally, in the Editor's Page, a nice piece from Drs. Joe Hill, Darren McGuire, and James de Lemos on “Circulation: Best Papers, 2021.” Gosh, really, really nice issue. Now let's go on, though, to the feature discussion, yeah? Dr. Greg Hundley: You bet. Dr. Mercedes Carnethon: Welcome to this episode of Circulation on the Run podcast. My name is Mercedes Carnethon, one of the associate editors, and I'm a professor of preventive medicine at the Northwestern University Feinberg school of Medicine. I'm really excited today to have a guest with us. Dr. Brendon Neuen, who has shared with us his really outstanding research on SGLT2 inhibitors and the risk of hyperkalemia in people with type-two diabetes, a meta-analysis. So welcome to our podcast today, Brendon. Dr. Brendon Neuen: Thanks very much for having me Mercedes. It's a real pleasure to be here. Dr. Mercedes Carnethon: Well, thank you for joining us. We're really pleased that you chose Circulation to share with us your really important findings. Can you tell us a little bit about the rationale for your study and how you carried out your work? Dr. Brendon Neuen: Yeah, absolutely. So we know that in people with diabetes and people with CKD, hyperkalemia is a common occurrence, and it's a problem for two reasons as you'd be aware. Firstly, it is associated with cardiac dysrhythmias and secondly, perhaps at least as importantly, it limits the optimal use of treatments that reduce kidney disease progression and heart failure events. So that is, agents that block the renin angiotensin aldosterone system. Dr. Brendon Neuen: We now know, and we've got robust evidence from large outcome trials, that SGLT2 inhibitors reduce the risk of heart failure and kidney disease progression in people with and without diabetes, but we haven't really, up and until now, systematically evaluated their effect on potassium outcomes, particularly hyperkalemia. And so we set out to assess whether these agents affect serum potassium levels and alter the risk of hyperkalemia as well as hypokalemia. Dr. Mercedes Carnethon: Thank you. That sounds like a really excellent and well needed study, given how much we've heard within the field about the benefits of SGLT2 inhibitors. It's nice to see a careful evaluation of what some of the considerations are in their use. So tell us a little bit about how you carried out this study and what you ultimately found. Dr. Brendon Neuen: What we did was, we identified clinical trials that enrolled people with type two diabetes at high cardiovascular risk or with chronic kidney disease. And what we did is, we approached the investigators of each of these trials and asked them to collaborate on a large meta-analysis using individual participant data. Dr. Brendon Neuen: What that allowed us to do was, then, standardize across all of the trials of different outcome definitions, and allowed us to assess the effective SGLT2 inhibitors on a primary outcome of time to first serum potassium greater than or equal to six, defined as serious hyperkalemia, as well as hypokalemia, investigator-reported hyperkalemia events, and a range of other potassium-related outcomes in a broad population, including people with chronic kidney disease, people with heart failure, and people using different concomitant medications, such as diuretics and MRAs in the background. Dr. Mercedes Carnethon: So thank you, Brendon, for the explanation of the use of the meta-analytic design and the entry criteria of type-two diabetes and chronic kidney disease. Can you tell us, what were the outcomes across these studies? Dr. Brendon Neuen: The primary outcome we evaluated was time to first serious hyperkalemia, defined as a serum potassium greater than or equal to six, as well as a range of other potassium-related outcomes, including investigator reported hyperkalemia, change in potassium over time, as well as hypokalemia, defined as a serum potassium less than 3.5. Dr. Brendon Neuen: What we found was that overall SGLT2 inhibitors reduce the risk of serious hyperkalemia by about 16%. And that effect was consistent across the agents within the class, and across different subpopulations and trials. This effect was supported by a 20% risk reduction in investigator-reported hyperemia events and importantly, there was no difference in risk of hypokalemia, that is a serum potassium less than 3.5, between SGLT2-treated and placebo-treated participants. Dr. Mercedes Carnethon: Thank you for that summary. You know, one of the very impressive aspects of this clinical trial is certainly the size and the number of participants. Brendon, I was really struck by your description of the consistency of findings across the subgroups. And in particular, when I reviewed the findings in the paper, I noticed that serious hyperkalemia was higher in those with poorer kidney function. Did you find that surprising? Dr. Brendon Neuen: From clinical practice, we know that one of the major determinants of hyperkalemia risk is kidney function. It's a major problem that we run into in people with more advanced CKD. And what that means is that for people with more advanced chronic kidney disease, who are at high risk of hyperkalemia, the absolute benefits of SGLT2 inhibition on hyperkalemia risk are likely greater in these individuals, because they're at high risk of this outcome. Dr. Brendon Neuen: Other patients who might be at increased risk of hyperkalemia include those with heart failure or those taking mineralocorticoid receptor antagonists at baseline. And so you'd expect that if the relative effects are consistent across many subgroups, then the absolute risk reductions are likely to be larger in people taking MRAs or people with more advanced CKD. Dr. Mercedes Carnethon: Thank you so much for summarizing the importance of these findings and what they mean for our clinical audience. It's wonderful to have this sort of information from a meta-analysis because it allows us large sample sizes, where we can do things like you describe, such as describing subgroup effects. Dr. Mercedes Carnethon: It also presents us with very robust evidence that can be taken into clinical practice for our clinical audience to use. Based on what you found, how do you anticipate that these findings can be used by our clinicians? Dr. Brendon Neuen: Well, thanks, Mercedes. I think the reduction in risk of hyperkalemia that is observed in these data suggests that SGLT2 inhibitors might enable better use of other proven therapies that reduce cardio-renal risk in people with chronic kidney disease and people with heart failure. We all know that in treating these high risk patients, hyperkalemia is a problem. And by reducing the risk of hyperkalemia with SGLT2 inhibitors, it might enable better use of renin angiotensin system blockade and mineralocorticoid receptor antagonists in people with chronic kidney disease and heart failure. Dr. Mercedes Carnethon: So you've provided a really excellent overall summary of the impact of these finding for clinical practice and the possible next steps. I wanted to end on a note of asking you what surprised you about these findings that might lead to further future investigations. Dr. Brendon Neuen: Thanks, Mercedes. I think that's a really interesting question. What was somewhat surprising, but also reassuring, was the consistency of the treatment effect on hyperkalemia, regardless of how we defined it, whether that was defined based on investigator-reported hyperkalemia events or central laboratory-measured serum, potassium levels, the treatment effect was very consistent. And I think that gives us some confidence about the robustness of these findings and their application to clinical practice. Dr. Mercedes Carnethon: Well, thank you so much, Brendon. I have really enjoyed this discussion with you today and this really important paper that is describing an important safety outcome for SGLT2 inhibitors in patients with type two diabetes. And again, I really want to thank you for sharing your excellent work with us here at Circulation. I anticipate that our readership, when they leave this podcast and pick up their journals, will be thrilled to read about all of the details about the excellent work that you and your team have carried out. So thank you very much for joining us today. Dr. Brendon Neuen: Thanks very much for having me, Mercedes. It was a real pleasure. Dr. Mercedes Carnethon: Thank you, and thank you again to our audience for joining us for this episode of Circulation on the Run. Speaker 5: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Guest Host Mercedes Carnethon, Author Brian Bergmark, and Associate Editor Parag Joshi as they discuss the article “Effect of Vupanorsen on Non–High-Density Lipoprotein Cholesterol Levels in Statin-Treated Patients With Elevated Cholesterol: TRANSLATE-TIMI 70.” Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-host. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center in Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well Carolyn, this week's feature, non-high density lipoprotein cholesterol levels in statin treated patients with elevated cholesterol. We're going to hear from the TRANSLATE-TIMI 70 study. But before we get to that, how about we grab a cup of coffee and discuss some of the other articles in the issue? Would you like to go first? Dr. Carolyn Lam: I would. And by the way, that feature is going to be all exciting. It was discussed at the American College of Cardiology. But okay, how about from cholesterol to vitamins? Let's start with the Greg quiz. Greg, which vitamins have been associated with arterial calcification? Is it A, B, C, D, E? Dr. Greg Hundley: I'm going to pick E and K. Dr. Carolyn Lam: You're smart. Indeed. Vitamin K2, also known as menaquinone-7 is the most effective co-factor for the carboxylation of proteins involved in the inhibition of arterial calcification. Furthermore, combined low vitamin K and low vitamin D have been associated with increased all-cause mortality risk. And so, today's paper is from Dr. Diederichsen from Odense University Hospital in Denmark and colleagues really present the first double-blind, randomized controlled trial to test whether vitamin K2, a drug-targeting processes of calcification in addition to vitamin D, could slow the progression of aortic valve calcification and stenosis. So, in a randomized double-blind multicenter trial, men from the community with an aortic valve calcium score above 300 arbitrary units on cardiac non-contrast CT were randomized to daily treatment with 720 micrograms of vitamin K2 plus 25 micrograms of vitamin D or matching placebo for 24 months. And the primary outcome was the change in aortic valve calcium score. Dr. Greg Hundley: Carolyn, so menaquinone-7 and aortic valve score. So, what were the results? Dr. Carolyn Lam: Menaquinone-7 had no major effect on the progression of aortic valve calcification as assessed by CT or echo. High-dose menaquinone-7 was, however, safe and well tolerated. Now, some limitations is that this external validity is limited to men aged 65 to 74 with aortic valve calcification scores of greater or equals to 300 arbitrary units. Thus, caution is needed if we extrapolate these findings and other pathways need to be explored in order to identify an effective therapy for this unmet clinical need. Dr. Greg Hundley: Wow, very nice Carolyn. Well, my first article comes to us from Dr. Michael Laflamme from the University Health Network. And Carolyn, human pluripotent stem cell-derived cardiomyocytes or hPSC-CMs exhibit promise for application in cardiac regeneration, but their translational potential is limited by an immature phenotype. So Carolyn, this research team hypothesized that large scale manufacturing of mature hPSC-CMs could be achieved via culture on polydimethylsiloxane, and we're going to call that PDMS, lined roller bottles and that the transplantation of these cells would mediate better structural and functional outcomes then with conventional immature hPSC-CMs populations. Dr. Carolyn Lam: Oh, that's neat, Greg. So, what did they find? Dr. Greg Hundley: Right, Carolyn. So, these authors demonstrated the economic generation of greater than one times 10 to the eighth mature hPSC-CMs per PDMS line roller bottle. And compared to their counterparts, PDMS matured hPSC-CMs exhibited increased cardiac gene expression and more mature structural and functional properties in vitro. More importantly, intracardiac graphs formed with PDMS matured myocytes showed greatly enhanced structured alignment, better host graft electromechanical integration, less pro arrhythmic behavior, and greater beneficial effects on contractile function. So in summary, Carolyn, this team describes practical methods for the scale generation of mature human pluripotent stem cell-derived cardiomyocytes and provide the first evidence that the transplantation of more mature cardiomyocytes yields better outcomes in vivo. And there's a wonderful editorial by Professor Murray entitled Flexing Their Muscles: Maturation of Stems Cell-Derived Cardiomyocytes on Elastomeric Substrates to Enhance Cardiac Repair. Dr. Carolyn Lam: Wow! That's really significant. Thank you, Greg. Well, the next paper is the largest genome-wide association meta-analysis of plasma ACE2 levels in over 28,000 individuals. And this is from Dr. Xia Chen from Fudan University and Dr. James Wilson from University of Edinburgh in UK, and their colleagues. And guess what, it focuses on severe acute respiratory syndrome coronavirus 2, the etiologic agent of COVID 19. And we know that that enters human cells using the ACE2 protein as a receptor. ACE2 is thus key to the infection and treatment of the coronavirus. ACE2 is highly expressed in the heart, respiratory and gastrointestinal tracts, playing important regulatory roles in the cardiovascular and other biologic systems. Dr. Greg Hundley: Wow, Carolyn. ACE2, and also a very important topic here with SARS-COVID-2. So, what did they find? Dr. Carolyn Lam: First, the overall heritability of ACE2 level is 16% of which 30% can be explained by 10 protein quantitative trait loci identified in this study. ACE2 level is genetically correlated with both COVID-19 and cardiovascular. Elevated ACE2 levels show a causal relationship with COVID-19 severity, hospitalization and infection as shown by Mendelian randomization analyses. ACE2 regulatory variants are enriched on DNA methylation sites in immune cells. Dr. Greg Hundley: Wow, Carolyn. So, elevated ACE2 and a causal relationship with COVID-19 severity. So tell us, what are the clinical applications of this really nice study? Dr. Carolyn Lam: The causal evidence of ACE2 suggests that pharmacological inhibition of circulating ACE2 may be a promising approach for treating COVID-19 or its comorbidities. Transcription factors that play essential roles in ACE2 generation could provide alternative paths to pharmacological modulation of ACE2 plasma levels. The genetic correlations between ACE2 and both COVID-19 and cardiovascular disease imply that the cardiovascular complications seen in COVID-19 patients may be intrinsic to the disease and mechanically or/and mechanistically-driven by ACE2. Isn't that neat? Dr. Greg Hundley: You bet, Carolyn. Boy, what an exciting issue. And we've got other articles in this issue. Dr. Carolyn Lam: Yeah. Now, let me start this time. There's an exchange of letters between Drs. Duan and Chang regarding the article “Therapeutic Exon Skipping Through a CRISPR-Guided Cytidine Deaminase Rescues Dystrophic Cardiomyopathy in Vivo.” There's a Perspective piece by Dr. Morris, “The Updated Heart Failure Guidelines: Time for a Refresh.” Love that piece! There's an AHA Update piece (AHA President's Page) by Dr. Elkin on The Road to Equity in Brain Health, and ECG challenge by Dr. Kolominsky, Electrical Extremists in a Critically ill Patient, and an On My Mind Paper by Dr. Paulus entitled “Border Disputes Between Heart Failure Phenotypes.” Dr. Greg Hundley: Wow, Carolyn. And I've got two Research Letters. The first from Professor Groeneveld entitled “Prevalence of Short-Coupled Ventricular Fibrillation in a Large Cohort of Dutch Idiopathic Ventricular Fibrillation Patients.” And then a second Research Letter from Professor Yamashita entitled “Single Cell RNA Sequence Reveals a Distinct Immune Landscape of Myeloid Cells in Coronary Culprit Plaques Causing Acute Coronary Syndrome.” Well Carolyn, now, we get to go onto our feature, vupanorsen on non-high-density lipoprotein cholesterol levels and catching up with TIMI 70. Dr. Carolyn Lam: Let's go. Dr. Mercedes Carnethon: So, good morning listeners. I'm really pleased to invite you to this episode of our Circulation on the Run podcast. For those of you who don't hear me often, I'm stepping in as a guest host today. My name is Mercedes Carnahan from the Northwestern University Feinberg School of Medicine. And I'm really excited to be joined today by Dr. Brian Bergmark, and associate editor, Dr. Parag Joshi. And we will have today Dr. Bergmark discussing his new article published with us on the effects of vupanorsen on non-HDL cholesterol levels in the TRANSLATE-TIMI 70 trial. We're really thrilled to have you with us here today, Brian, to talk about the really important findings coming from this trial. So to start us off, just tell us, what did you find? Dr. Brian Bergmark: Great. Thank you so much. It's really a pleasure to be here and I'm grateful for the opportunity. So, in the big picture, despite numerous agents to reduce lipid-mediated cardiovascular risk, obviously, residual risk remains and there are novel targets to address that risk. One of them is angiopoietin-like 3, which is a protein made in the liver. Angiopoietin-like 3 or ANGPTL3 inhibits lipoprotein lipases among other lipases, and thereby interferes with metabolism of triglyceride-rich lipoproteins. And so, the idea here was that if ANGPTL3 could be inhibited that LPL or lipoprotein lipase function could be augmented and metabolism of these lipoproteins could be augmented. And so, what we did is we took patients with an elevated non-HDL cholesterol, at least 100 milligrams per deciliter, and elevated triglycerides, 150 to 500 milligrams per deciliter, and randomized them to placebo or one of seven doses of vupanorsen, which is an antisense oligonucleotide, which inhibits the synthesis of ANGPTL3 in the liver. We then follow them to see what the impact was on their non-HDL cholesterol, as well as other lipid parameters through 24 weeks. Dr. Mercedes Carnethon: Thank you so much. It's a wonderful design, and I'm really excited to hear a little bit more about what you found. Dr. Brian Bergmark: Great. So, the primary endpoint was the change in non-HDL cholesterol from baseline to 24 weeks. And we did find that all vupanorsen regimens reduced non-HDL cholesterol in a statistically significant manner. The magnitude of that effect was up to 27.7% in one of the dose arms or about 28%. We also saw a statistically significant reductions in the target ANGPTL3 up to about a 95% reduction in the highest dose arm, as well as statistically significant reductions in triglycerides at all of the dose regimens. The effect on LDL cholesterol and on apolipoprotein B or apo B was variable across regimens and only statistically significant in a few of the dose arms. We also found several safety signals. One, there appeared to be higher rates of injection site reactions in the skin at higher total monthly doses. We also found higher rates of elevation in liver enzymes, AST and ALT at higher total monthly doses. And we also found significant increases in hepatic fat fraction or the fat content of the liver at higher total monthly doses. Dr. Brian Bergmark: In the end, we found that while statistically significant, the magnitude of the reduction in non-HDL cholesterol was modest as was the reduction in apo B. And so, the goal here was to find a dose that might have a reduction of a magnitude that would be clinically meaningful for cardiovascular risk reduction. We were underwhelmed by the magnitude of that reduction, and then it was paired with these safety signals, which if there's interest, we could get into more detail in our thinking about why those occurred, what the implications are, but suffice it to say that there were medically meaningful safety concerns paired with a modest reduction in non-HDL cholesterol. Dr. Mercedes Carnethon: Thank you for that excellent summary. Before I turn it over to the associate editor, I read this with great interest, and in particular, looking at one of the first figures in the paper, which is demonstrating the adjusted change at 24 weeks across different doses and based on how frequently the doses were given the four week as compared with the two week. And one thing that really stood out to me was the clear dose response with the four week regimens with the higher doses appearing to demonstrate the greatest reductions but a less clear signal with the two week regimens. Do you have any hypotheses about why these patterns appeared so different? Dr. Brian Bergmark: Yeah. It's a great question. So, the responsiveness of this is something of interest here I think. So, if you look at the effect of the drug on its target, ANGPTL3, there is a very clear dose response, so there's no doubt that higher doses were impacting the target ANGPTL3 to a greater extent. So, one of the most direct effects would be on triglycerides, one of the most direct lipid effects, and that appears pretty close to a dose response relationship within each of these frequencies of administration. But once you start getting to non-HDL cholesterol, it starts to break down a bit. And is it simply because of random chance or is there actually something distinct going on with how the lipids are being metabolized? Dr. Brian Bergmark: That is something we are diving into. So, the hope would be that we actually reduce apo B, the number of these actually circulating lipoproteins as has been demonstrated with the monoclonal antibody. It's possible that with this other different mechanism in the antibody, this antisense oligonucleotide, perhaps, we're simply shifting the content of these lipoprotein molecules and decreasing the triglyceride content but not actually meaningfully modifying the amount of apo B, LDL cholesterol. And that might be part of what we're seeing with the more muted relationship between dose and the effect on non-HDL cholesterol. I don't know for certain we are diving into this a bit more with other lipid fractions, et cetera. Dr. Mercedes Carnethon: Oh, well, thank you so much for that explanation. I know that a number of people, this was extremely well received when shared at the recent American College of Cardiology meetings, and so I was really thrilled to find that this was appearing in the journal circulation. So Parag, I'm really interested in hearing your perspectives on why we knew that this was certainly a priority paper for us. Dr. Parag Joshi: Yeah. Let me first start, Brian, congratulations. Fantastic work. And we were excited to receive the paper. I think really hard to pull off trials right now or in the last couple years, so kudos to you. And I echo the sentiments from Mercedes. This is great work. Really important space, the residual risk space I think is very important of course and is critical to moving forward with improving cardiovascular health. So, one of the big picture questions and as we get to this triglyceride-rich lipoprotein lowering space, certainly, there's strong associations with residual risk, but can we impact that risk? And here, we're starting to explore that. And I think when you think of the lipoprotein space, many of us are interested in what is the effect on these lipoproteins as opposed to the cholesterol content or the triglyceride content. And non-HDL cholesterol or apo B, clearly, the better, stronger markers for that risk, so we were really excited to see this paper. Dr. Parag Joshi: And as Brian mentioned, unfortunately, not the strongest impact here on those measures. And I want to dive into that a little more because I think that carries significant implications for the space, and I'd love to hear your thoughts on that. But overall, really fantastic work. I think my first question really is around the apo B aspect of this and the less than anticipated lowering of those levels. You hinted at this in terms of, is this shuffling cholesterol and triglycerides across particles, or do you think this could be the mechanism by which this happens through ANGPTL3? You do inhibit the levels quite a bit. Did we just miss that... Is this not the right target? What do you think? Dr. Brian Bergmark: Yeah, it's a great question. I do think the target itself holds great promise. Obviously, a monoclonal antibody against this same target results in major reductions in apo B, LDL cholesterol, and the latter through a mechanism that is not really known but is not dependent on the LDL receptor, and therefore has real clinical utility that's approved for people with familial homozygous hypercholesterolemia. Beyond that, of course, in genetic studies, there's a clear association with loss of function in the ANGPTL3 gene and lower levels of all of these lipids, lower rates of coronary artery disease, et cetera. Dr. Brian Bergmark: So, I think it's not that this pathway is not promising and actually already being taken advantage of, I think it's that this particular agent acting through this mechanism was not able to achieve a necessary efficacy with reasonable safety. Some genetic data suggests that there is not actually a dose response between a reduction or loss of function in ANGPTL3 and reduction in apo B or lower levels of apo B and non-HDL cholesterol, but it really requires your complete elimination of ANGPTL3 function, which is probably, likely achieved with the monoclonal antibody. And so, even though we had quite large reductions with the antisense oligonucleotide, perhaps, we just didn't cross that threshold that's needed to modify the lipid panel in the way that would've been clinically meaningful. Dr. Parag Joshi: Yeah. I think that's fantastic as you allude to with evolocumab and the impact that has on apo B levels. I didn't think of it as a threshold effect, but that makes a lot of sense as maybe that just getting to that tipping point is where the issue is here. In terms of the liver signal, what were your thoughts on that? And is that something that we should expect to see in ASOs or do you think it's specific to this compound? Dr. Brian Bergmark: Yeah, I don't know. That was unexpected. Right, there are two liver signals and it's unclear how related they are. One is the inflammation of the liver as indicated by the elevation in enzymes, and then the other is the fat accumulation. So with respect to the fact, if anything, genetic data suggests perhaps loss of function in ANGPTL3 might result in lower rates of hepatic steatosis. In animal models, the antisense oligonucleotide reduces liver fat, and so there's, there was promise going into this that this could actually be beneficial for non-alcoholic fatty liver disease. And additionally, there's not data to suggest that the monoclonal antibody increases liver fat. So, there's not a lot to support this as being an on-target effect that by inhibiting ANGPTL3, by that pathway, the liver fat was increased. So, I think a reasonable person might wonder whether this was an off-target effect of the drug. Dr. Brian Bergmark: By what mechanism that occurred, I don't know, what the implications would be for other related agents, I don't know. And then similarly, the liver enzyme elevations, is that related to this? I'm not exactly sure, but also unexpected and I think off-target. But that sort of intrinsic to this mechanism of hepatic targeting, is this something we need to be worried about for other agents in this class or not? I don't know. Obviously, we can't answer that from this single study. We are going to dive into it a bit more to try to overlay patients with hepatic fat accumulation, liver enzymes, et cetera. Of course, both of those happen more at higher doses. How much we can really parse this? I'm not sure yet. Dr. Parag Joshi: Yeah. That's really fascinating. I think the appeal of this paper to the circulation audience is that you have a really exciting novel target and pathway to explore here but somewhat divergent results from what's existing in this space. And I think that raises a lot of questions, really interesting questions going forward for this space. For the ANGPTL3 pathway, what do you see there coming down the line or what are your thoughts on that going forward for this target and ways to approach risk related to it? Dr. Brian Bergmark: Yeah. Great. Thank you. Yeah. No, so I agree. I think moving into this other end of the spectrum of triglyceride-rich lipoproteins, et cetera, I think this is where we're headed and this is why we do the trial. We weren't expecting these things that's why you do this experiment, and this is what we found. So now, where do we go from here? So there are, of course, other ways beyond the monoclonal antibody of targeting ANGPTL3 specifically. There's siRNA, there is gene therapy being investigated. So, I think all of them hold an great promise. And of course, we will need to see as those therapies move along what the actual trials show. And then there are, of course, other pathways that are of interest, APOC3, for instance. So, I think there's a lot more in this space that's coming down the line. Dr. Parag Joshi: Yeah, absolutely. I think it's a really exciting space, and we're really happy to get this paper as one piece of that whole puzzle. So, thank you. Dr. Mercedes Carnethon: Yes. And I echo that as well. And as a methodologist myself, I'm always really pleased to see such well-designed studies. I think this was sophisticated in many aspects in testing different dosing and different timing of the dosing. And also, I'm really impressed by your inclusion criteria, particularly when I noted that 44% of the participants were female, and that you reported those stratum-specific effects. I just had a final question as we wrap up. You acknowledge a nominally significant interaction by sex and I see, for example, that it appears that the magnitude is larger possibly in the relatively smaller subset of females as compared with males. Is this something to pay attention to or do you think this is just some type of an artifact related to greater variability because the group is smaller? Dr. Brian Bergmark: Yeah, it's a good question. So, this is the burning question. We had no a priority reason to suspect that biologically and we are not adjusting for multiple testing in the key value of 0.04. So just to put my money down, I would say, I would guess it's random chance. We found it. It's worthy of looking into a bit more. There were, of course, the important implications for other drugs, et cetera. So, I think it's worth diving into as we will, but are we likely to uncover some biological difference? I doubt it. I wouldn't guess. There are other subgroups where I think at least upfront, you might expect there could be a difference. So, there are thoughts about insulin's effect on LPL. Could diabetes status have an interaction with the drug? I think though not statistically significant, it's also something worth looking into that group and the subfractions of the lipid panel and all of that stuff. So, I think it's all worth looking into but cautiously with the constraints. Dr. Mercedes Carnethon: Well, thank you so much for that explanation. And I've really enjoyed this discussion with you today, Brian, and you, Parag. I've certainly learned a lot and I'm really excited to see this excellent work coming out in the journal circulation. So, thank you very much for your time this morning and thank you to our listeners. Wrapping up this episode of Circulation on the Run. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Vasan Ramachandran and Associate Editor Mercedes Carnethon as they discuss the article "Temporal Trends in the Remaining Lifetime Risk of Cardiovascular Disease Among Middle-Aged Adults Across 6 Decades: The Framingham Study." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast, summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center in Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, I'm so excited about today's feature paper. You see, I trained at the Framingham Heart Study and today's feature paper talks about the temporal trends in the remaining lifetime risk of cardiovascular disease among middle aged adults across six decades in the Framingham Heart Study. Truly a landmark study and a discussion nobody wants to miss. But first, let's talk about the other papers in today's issue, and I understand that you've got one ready. Dr. Greg Hundley: You bet Carolyn. I'll get started first. Thank you. So my first paper comes from Dr. Daniel Mark from Duke University and it refers to the ISCHEMIA trial. Dr. Carolyn Lam: Ooh, could you please first remind us what is the ISCHEMIA trial and are you presenting a substudy, is that correct? Dr. Greg Hundley: Right, Carolyn. So the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches, or ISCHEMIA, compared an initial invasive strategy with an initial conservative strategy in 5,179 participants with chronic coronary disease and moderate or severe ischemia. And this sub study of the ischemia research program included a comprehensive quality of life analysis. Dr. Carolyn Lam: So very interesting. What did they find Greg? Dr. Greg Hundley: Right, Carolyn. So this study included 1,819 participants. 907 in the invasive, 912 in the conservative. And collected a battery of disease specific and generic quality of life instruments by structured interviews at baseline. And then at three, 12, 24 and 36 months post randomization, and then finally at study closeout. Now Carolyn, these assessments included an angina related quality of life assessment from the 19 item Seattle Angina Questionnaire, a generic health status assessment, an assessment of depressive symptoms, and for North American patients, cardiac functional status from the Duke Activity Status Index, or DASI. In this study, Carolyn, in terms of results, the median age was 67 years and about 20% were women and about 16% were nonwhite. So Carolyn, getting to the results. The estimated mean difference for the SAQ 19 summary score favored invasive therapy. And remember the SAQ 19 was the Seattle Angina Questionnaire. Dr. Greg Hundley: Next, no differences were observed in patients with rare or absent baseline angina. Next, among patients with more frequent angina baseline, those randomized to invasive had a mean point higher score on the SAQ 19 summary score than the conservative approach, with consistent effects across all of the SAQ subscales including physical limitations, angina frequency and quality of life health perceptions. For the DASI, and remember DASI refers to the Duke Activity Status Index, no difference was estimated overall by treatment. But in patients with baseline marked angina, DASI scores were higher for the interventional arm. Whereas patients with rare or absent baseline angina showed really no treatment related differences. Dr. Carolyn Lam: Oh, okay. So a lot of results. What's the take-home message, Greg? Dr. Greg Hundley: Right, Carolyn. Glad you asked. So in the ISCHEMIA comprehensive quality of life substudy, patients with more frequent baseline angina reported greater improvements in the symptom physical functioning and psychological wellbeing dimensions of quality of life when treated with an invasive strategy. Whereas patients who had rare or absent angina baseline reported no consistent treatment related quality of life differences. Dr. Carolyn Lam: Wow. Thank you, Greg. Very interesting indeed. Now from angina to now cholesterol. Now, cholesterol guidelines typically prioritize primary prevention statin therapy based on 10 year risk of cardiovascular disease. Now the advent of generic pricing may in fact justify expansion of statin eligibility. Moreover, 10 year risk may not be the optimal approach for statin prioritization. So these issues were looked at in this next paper by authors led by Dr. Kohli Lynch from Northwestern University and colleagues who estimated the cost effectiveness of expanding preventive statin eligibility, and evaluated novel approaches to prioritization from a Scottish health sector perspective. A computer simulation model predicted long term health and cost outcomes in Scottish adults, age 40 years or more. Dr. Greg Hundley: So Carolyn, what did they find? Dr. Carolyn Lam: The advent of generic pricing has rendered preventive statin therapy cost effective for many adults. Absolute risk reduction guided statin therapy, which is based on 10 year cardiovascular disease risk and non HDL cholesterol levels, is cost effective and would improve population health. Whereas age stratified risk thresholds were more expensive and less effective than alternative approaches to statin prioritization. So guidelines committees may need to expand statin eligibility and consider new ways to allocate statins based on absolute risk reduction rather than 10 year risk thresholds. Dr. Greg Hundley: Very nice Carolyn. Always important, new information regarding statin therapy. Well Carolyn, my next paper comes to us from the world of preclinical science. And Carolyn, as you know, the regenerative capacity of the heart after myocardial infarction is limited. And these authors led by Dr. Tamer Mohamed from University of Louisville previously showed that ectopic introduction of Cdk1, CyclinB1 and Cdk4, CyclinD1 complexes and we'll refer to those now as 4F, promoted cardiomyocyte proliferation in 15 to 20% of infected cardiomyocytes in vitro and in vivo and improved cardiac function after MI in mice. So Carolyn, in this study using temporal single cell RNA sequencing, the investigative team aimed to identify the necessary reprogramming stages during the forced cardiomyocyte proliferation with 4F on a single cell basis. And also using rat and pig models of ischemic heart failure, they aim to start the first preclinical testing to introduce 4F gene therapy as a candidate for the treatment of ischemia induced heart failure. Dr. Carolyn Lam: Oh, wow Greg. So what did they find? Dr. Greg Hundley: Several things, Carolyn. First, temporal bulk and single cell RNA sequencing and further biochemical validations of mature HIPS cardiomyocytes treated with either LAcZ or 4F adenoviruses revealed full cell cycle reprogramming in 15% of the cardiomyocyte population at 48 hours post-infection with 4F. Which was mainly associated with sarcomere disassembly and metabolic reprogramming. Second Carolyn, transient overexpression of 4F specifically in cardiomyocytes was achieved using a polycistronic non-integrating lentivirus encoding the 4F with each driven by a TNNT2 promoter entitled TNNT2-4F polycistronic-NIL. Now this TNNT2-4F polycistronic-NIL or control virus was injected intra myocardial one week after MI in rats, so 10 per group, and pigs, six to seven per group. Dr. Greg Hundley: And four weeks post-injection the TNNT2-4F polycistronic-NIL treated animals showed significant improvement in left ventricular injection fraction and scar size compared with the control virus treated animals. And four months after treatment, the rats that received TNNT2-4F polycistronic-NIL still showed a sustained improvement in cardiac function without obvious development of cardiac arrhythmias or systemic tumorigenesis. And so Carolyn this study advances concepts related to myocellular regeneration by providing mechanistic insights into the process of forced cardiomyocyte proliferation and advances the clinical feasibility of this approach by minimizing the oncogenic potential of the cell factors, thanks to the use of a novel transient and cardiomyocyte specific viral construct. Dr. Carolyn Lam: Wow. What a rich study. Thanks so much, Greg. Dr. Greg Hundley: Well, Carolyn, how about if we see what else and what other articles are in this issue. And maybe I'll go first. So there's a research letter from Dr. Wu entitled Modeling Effects of Immunosuppressive Drugs on Human Hearts Using IPSC Derived Cardiac Organoids and Single Cell RNA Sequencing. Carolyn, there's an EKG challenge from Dr. Yarmohammadi, entitled “Fast and Furious, A Case of Group Beating in Cardiomyopathy.” And then finally from Dr. Tulloch, a really nice Perspective entitled “The Social Robots are Coming, Preparing For a New Wave of Virtual Care in Cardiovascular Medicine. Dr. Carolyn Lam: Oh, how interesting. Well, also in the mail back is an exchange of letters of among Drs. Lakkireddy, Dhruva, Natale, and Price regarding Amplatzer Amulet Left Atrial Appendage Occluder versus Watchman Device for stroke prophylaxis, a randomized control trial. All right. Thank you so much, Greg. Shall we go on to our feature discussion now? Dr. Greg Hundley: You bey. Welcome listeners to our feature discussion today. And we're so fortunate we have with us today, Dr. Vasan Ramachandran from Boston University and our own Associate Editor, Dr. Mercedes Carnethon from Northwestern University in Chicago. Welcome to you both. And Vasan, let's start with you. Could you describe for us some of the background information pertaining to your study and what was the hypothesis that you wanted to address? Dr. Vasan Ramachandran: Thank you, Greg, first of all for having me. So we know two facts. One is that heart disease and stroke disease death rates and incidents are declining over the last six decades in the United States. Juxtapose against that is also the observation that there is rising incidence of obesity and overweight, and also a rising burden of diabetes. There are a lot of advances in our ability to treat high blood pressure, high cholesterol, as well as high blood sugar. So we wanted to ask the question, given the historic trends in control awareness of risk factors and their control, interrupted by this escalating burden of obesity, overweight, and diabetes, what is the lived experiences of people over time in terms of the risk of developing heart disease or stroke using a metric we call as the remaining lifetime risk of developing heart disease or stroke. Dr. Greg Hundley: The hypothesis you wanted to address? Dr. Vasan Ramachandran: The hypothesis we wanted to address was that perhaps the decline in the incidence of heart disease and stroke may have decreased over time given the escalating burden of overweight, obesity and diabetes. Dr. Greg Hundley: Very nice. And can you describe for us your study population and your study design? Dr. Vasan Ramachandran: Thank you, Greg. So the Framingham Heart Study is one of the oldest running epidemiological studies in the world. We have multiple cohorts. The study began in 1948 with the original cohort, the offspring cohort enrolled in 1971, third generation cohort in 2002, and two minoritized cohorts in the 1990s and 2002. So we have an observation period of different cohorts over a six decade period. So we asked the question, if you were a participant in the Framingham study between 1960 and 1979 and then 1980 to 1999, and then 2000 to 2018, what was your lifetime risk of experiencing a heart disease or stroke in the three different time periods? Is it going down, is it steady or is it going up? Dr. Greg Hundley: Very nice. And so, Vasan, describe your study results. Dr. Vasan Ramachandran: Look, what we found was if you look at the first, the 20 year period from 1960 to 1979, and compare that with the latest, which is 2000 to 2018, in the initial time period, the lifetime risk of developing heart disease or stroke in a man was pretty high. It was about one in two. And that for a woman was about one in three. So when you come to the latest epoch, what we find that the risk of one in two men had dropped to about one in three men in the latest decade. For women, the risk declined from what was one in three in the earlier epoch to one in four. So approximately there was about a 36% reduction in the lifetime probability of developing heart disease or stroke across the six decade period of observation. Dr. Greg Hundley: Very nice. And so help us a little bit, put the context of your results into what that might mean for us today as we are managing patients with atherosclerotic disease. Dr. Vasan Ramachandran: Yes, Greg. What it means is that the permeation of the advances in science in terms of the screening of risk factors, awareness of risk factors, medications to lower these risk factors effectively, the clinical trials that have given us these new medications, they may have translated into a reduction in risk over time. That the lived experience of people in the later decades is better in terms of having a lower risk of heart disease or stroke as the consequence of multiple advances that have happened in heart disease and stroke. Dr. Greg Hundley: Well, thank you so much Vasan. Well listeners, now we're going to turn to our Associate Editor, Mercy Carnethon. And Mercy, you have many papers come across your desk. What attracted you to this particular paper and how do you put these results really in the context of other science pertaining to risk associated with populations that may have atherosclerotic cardiovascular disease? Dr. Mercedes Carnethon: Thanks so much for that question, Greg. And again, Vasan, I really thank you and your team for bringing forth such outstanding research. You know, as cardiovascular disease epidemiologists, we were all raised and taught that what we know about risk factors for cardiovascular disease are based on the Framingham cohort. And so I was really excited to see this very comprehensive piece of work that characterized what the Framingham study has identified and also leverages the unique characteristics of a study that started in 1948. Dr. Mercedes Carnethon: So, you know, we're almost 75 years in and actually has the ability that cross sectional studies don't have to look over longer periods of time at risk. And you know, when we think about papers that excite us, that we really want to feature in circulation, they are papers that teach us something new. And I will say there were aspects of this work that confirmed what I had heard but had not seen using empirical data. Namely that the remaining lifetime risks for developing cardiovascular disease were going down over time, and they were going down secondary to better management and recognition of the risk factors that the Framingham cohort study had really been instrumental in identifying in the first place. Dr. Mercedes Carnethon: There were surprising elements of the paper. The surprising elements being that I think as you brought up earlier, we were concerned that risk factors that were on the rise, such as obesity, were threatening these increases in life expectancy. And it was really nice to see that the findings held, even in the face of rising risk factors. And just to summarize, what I really like about this piece when we situate it within circulation, where we are addressing clinical treatment factors, where we're also featuring clinical trials and even other epidemiologic studies, is that your work identifies for us the overall context in which the clinicians who read the journal are thinking about managing patients and where we're going. It highlights our successes, but it also really brings up what we need to do next. And I look forward to hearing from you about where you think this may be headed. Dr. Greg Hundley: Well, Mercy, you're teeing us up for that next question. Vasan, what do you think is the next study or studies that need to be performed in this space? Dr. Vasan Ramachandran: Thank you, Greg and Mercy, for your kind comments. Like I shared, this is a success story for a predominantly white population in the Northeast. We are very much aware about the heterogeneity and the geographic variation in heart disease burden in our country. So one of the success stories interpretation might be this represents the upper bound. What can happen to a population that is compliant with screening of risk factors, awareness of risk factors, treatment and healthcare access. I think the next set of studies should broaden the study population to bring in additional populations that are more diverse, that are also followed up over a period of time to assess and put the current observations in the appropriate context. Do we see similar findings longitudinally in other cohorts with non-white participants? Is it different, is their lived experience different? If so, why? And that could inform us how we can reach the success story and replicate it across the entirety of our country. Dr. Greg Hundley: And Mercy, do you have anything to add? Dr. Mercedes Carnethon: I do. You know, I really like that focus on broadening to whom these results are applicable. We've undergone a lot of shifts within our country and also around the world. You know, circulation, we have a worldwide readership. I would love to see this sort of work replicated across different countries to the extent that we have the data to do so, recognizing that limitation. But I'd love to see work focus on comparing how these things change in low income countries, middle income and high income countries, so that we can really think about resource allocation and find strategies to try to replicate the successes that we are seeing based on the data from the Framingham heart and offspring studies. Dr. Greg Hundley: Excellent. Well listeners, we really appreciate the opportunity to get together today with Dr. Vasan Ramachandran from Boston University and our own Associate Editor, Dr. Mercedes Carnethon from Northwestern University in Chicago. And really appreciate them for bringing us these epidemiologic data from the Framingham cohort, indicating that over the past decades, mean life expectancy increased and the remaining lifetime risk of atherosclerotic cardiovascular disease decreased across individuals in the cohort, even after accounting for increasing incidences of other cardiovascular risk factors like obesity and smoking. Well on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. Dr. Greg Hundley This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Andrew Chapman and Guest Editor Harvey White as they discuss the article "Coronary Artery and Cardiac Disease in Patients With Type 2 Myocardial Infarction: A Prospective Cohort Study." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor and Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Greg Hundley: Well, Carolyn, this week's feature on April 19th refers to coronary artery and cardiac disease in patients with type two myocardial infarction. And we will have more to learn about that, but how about we grab a cup of coffee and get started with some of the other articles in the issues. Dr. Carolyn Lam: Please? You first. Dr. Greg Hundley: Thanks Carolyn. So Carolyn, this team investigated the observational and causal associations of 90 cardiovascular proteins, which were measured using affinity based proteomic assays to estimate their association with incident heart failure. And so to accomplish this, the team, led by Dr. Thomas Lumbers from University College of London, utilized a fixed effect meta-analysis of four population-based studies comprising a total of 3,000 plus participants with 732 heart failure events. Now, the causal effects of heart failure associated proteins were then investigated by Mendelian randomization using CIS protein, quantitative loci, genetic instruments identified from genome-wide association studies or GWAS and over 30,000 individuals. Dr. Carolyn Lam: Wow! Big study, important stuff. So what did they find? Dr. Greg Hundley: Right Carolyn, several things. So 44 of 90 proteins were positively associated with the risk of incident heart failure. Now, among these eight proteins had evidence of a causal association with heart failure that was robust to multiverse sensitivity analysis. Higher CSF1, Galectin-3 and KIM-1 or kidney injury molecule one were positively associated with the risk of heart failure, whereas higher adrenomedullin chitinase-3 like-protein-1, cathepsin L1, and fibroblast growth factor 23, and matrix metalloproteinase 12 were protective. And so Carolyn in summary, the team identified 44 circulating proteins that were associated with incident heart failure of which eight showed evidence of a causal relationship, and seven were identified as being drugable, including adrenomedullin, which represents a particularly promising drug target. Dr. Greg Hundley: Additionally, Carolyn, this is a really interesting study as the teams approach demonstrates a tractable roadmap for the triangulation of population genomic and proteomic data for the prioritization of therapeutic targets for complex human diseases. Dr Carolyn Lam: Wow! Super cool. Yeah, indeed the methodology is significant there too. Thanks Greg. Well, this next paper deals with hypertrophic cardiomyopathy and we know that familial hypertrophic cardiomyopathy is the most common inherited cardiac disease and is typically caused by mutations in genes encoding sarcomeric proteins that regulate cardiac contractility. But how exactly is the dysregulated sarcomeric force production sensed and how does that lead to pathological remodeling? Dr. Carolyn Lam: Well, today's authors and they are Dr. Qyang from Yale University School of Medicine and colleagues gained insights from a severe phenotype of an individual with hypertrophic cardiomyopathy and a second genetic alteration in a sarcomeric mechanosensing protein. They derived cardiomyocytes from patient specific induced pluripotent stem cells and developed robust, engineered heart tissues to study human cardiac mechanobiology at both cellular and tissue levels. They further used computational modeling for muscle contraction and rescue of disease phenotype via gene editing and pharmacological interventions to identify a new mechanotransduction pathway in hypertrophic cardiomyopathy. Dr. Greg Hundley: Wow, Carolyn! Tell us more about this new pathway. Dr. Carolyn Lam: The study presents a novel biomechanical mechanism by which enhanced myofilament contractile force generation due to sarcomeric mutations, destabilize the muscle limb protein Z-disc mechanosensory complex, and this leads to disinhibition of calcineurin nuclear factor of activated T-cells or NFAT signaling and consequently leads to hypertrophy. Normalization of hypercontractile force in proband cardiomyocytes either with gene editing approaches or with ectomyosin crossbridge inhibitor mavacamten, resulted in an increase in Muscle Lim Protein levels, a decrease in that calcineurin and fat activity and a rescue from the hypertrophic cardiomyopathy defects. Dr. Carolyn Lam: The authors provided evidence that the common Muscle Lim Protein W4R variant is an important modifier that worsens the disease severity of hypertrophic cardiomyopathy, but alone does not appear sufficient to cause disease. All in all, these data established a foundation for developing innovative mechanism-based treatments for hypertrophic cardiomyopathy that stabilize the Z-disc Muscle Lim Protein mechanosensory complex. Dr. Greg Hundley: Oh, wow Carolyn! What a really nice mechanistic study and important new information too. Well, Carolyn, my next paper comes to us from Dr. Anthony Rosenzweig, Massachusetts General Hospital at the Harvard Medical School and Carolyn the LV myocardium increases in mass in response to pathological as well as physiological stimuli. The former or pathologic hypertrophy, often proceeds cardiomyocyte loss and heart failure. The latter or physiologic, paradoxically protects the heart enhances cardiomyogenesis. The mechanisms underlying these differences remain incompletely understood. Now, while long non-encoding RNAs are important in cardiac development and disease associated with pathologic hypertrophy, less is known about their roles in physiologic hypertrophy or cardiomyogenesis. Dr Carolyn Lam: Oh, interesting! So what did these authors find about link RNAs and physiologic hypertrophy? Dr Greg Hundley: Right, Carolyn. So in this study of mice, the authors identified exercise regulated cardiac link RNAs termed lncExACT and lncExACT1 was evolutionarily conserved and decreased in exercised hearts, but increased in experimental heart failure. Cardiac lncExACT1 over expression caused pathological hypertrophy and heart failure while lncExACT1 inhibition induced physiologic hypertrophy and cardiomyogenesis protecting against cardiac fibrosis and dysfunction. Dr. Greg Hundley: Now, lncExACT1 functioned by regulating microRNA 222 calcineurine signaling, and Hippo/Yap1 signaling through DCHS2. Cardiomyocyte DCH2 over expression in zebra fish induced pathological hypertrophy and impaired cardiac regeneration promoting scarring after this injury. In contrast mirroring DCH2 deletion, induced physiological hypertrophy and promoted cardiomyogenesis. Dr. Carolyn Lam: Oh, wow, Greg! Okay. Could you wrap it up for us? What's the take home message? Dr. Greg Hundley: You bet, Carolyn. These studies identify that lncExACT1 DCHS2 is a novel pathway regulating cardiac hypertrophy and cardiomyogenesis. lncExACT1 DCHS2 acts as a master switch, toggling the heart between physiological and pathological growth to determine functional outcomes, providing a potentially tractable therapeutic target for harnessing the benefits of exercise. Dr Carolyn Lam: Oh, thank you, Greg. Well, also in this issue is an In-Depth paper by Dr. Luesebrink on “Percutaneous Transvalvular Micro Exhale Flow Pump Support in Cardiology.” There's a Research Letter by Dr. Shekhar on “Age and Racial or Ethnic Disparities in Pediatric Out-of-Hospital Cardiac Arrest.” Dr. Greg Hundley: Right, Carolyn. Well, Carolyn from the mailbag, we have a Letter to the Editor from Dr. Gronda entitled “The Failing Heart and SGLT2 inhibitor Renal Effects: Are They Mutually Engaged in Business?” We also have from Dr. Viskin, an ECG challenge entitled “Sinus Node Dysfunction with a Nice Twist.” And finally, Carolyn, there's a Perspective piece from Dr. Schulman entitled “The Price and Quality of the Generic Pharmaceutical Market.” Well, how about at Carolyn we get on our feature discussion involving type two myocardial infarction. Dr. Carolyn Lam: Yay! Let's go. Dr. Greg Hundley: Well, listeners, welcome to our feature discussion on this April 19th and we have with us today, Dr. Andrew Chapman from Edinburg, Scotland and Dr. Harvey White from Auckland, New Zealand. Welcome gentlemen. And we'll start with you, Andrew. First, could you describe for us some of the background information that went into the preparation of your study? Dr Andrew Chapman: Good morning and good evening and thank you very much for the invitation. So type two myocardial infarction is an interesting diagnosis. It was first introduced in around 2007 in recognition that patients could have heart injury when they were in hospital with other problems that led to an imbalance in myocardial oxygen supply, or an unmet need in myocardial oxygen demand, without the presence of atherothrombotic coronary artery disease. We don't know a great deal about these patients. Dr. Andrew Chapman: There have been a number of observational cohort studies, including from ourselves in Scotland, which have demonstrated the outcomes for this patient group are poor. We know only around one-third of patients with type two MI, survive to five years after diagnosis. And we also know, and previously demonstrated from patients in Scotland that those with underlying coronary artery disease actually had the worst outcomes and were at increased risk of future myocardial infarction events due to plaque rupture. So we hypothesized that patients with type two myocardial infarction may have failed a physiological stress test due to another illness and we wanted to investigate what the prevalence of underlying coronary artery disease and/or structural heart disease was, using a panel of different imaging modalities. Dr. Greg Hundley: And so Andrew tell us the hypothesis that you wanted to address? Dr. Andrew Chapman: So we believed that observational evidence suggested that coronary artery disease was important in patients with type two myocardial infarction and we felt that this was increasing their susceptibility to these events. Our primary hypothesis was that the majority of patients with type two myocardial infarction would have underlying coronary artery disease, which was previously quiescent undetected. Dr. Greg Hundley: Tell us a little bit about the study design and the study population that you use to answer this question. Dr. Andrew Chapman: Demand MI is to our knowledge, the first prospective observational cohort study in which patients who were in hospital with evidence of myocardial injury, so a raised cardiac troponin, were screened for the presence of supplier demand imbalance and the clinical diagnosis of type two MI. Now, in those patients that we were able to recruit, we did obviously have important exclusion criteria, but we designed a series of different investigations depending on individual patient risk factors and the appropriateness of such, but the primary goal was to undertake coronary angiography, ideally using an invasive coronary angiogram, which would allow us to undertake additional testing, such as plaque imaging and pressure wire study, to look for the functional consequences of stenosis. In those not fit for an invasive angiogram, we undertook CT coronary angiography. And in all patients we undertook structural imaging and we aimed to do cardiac MRI in all. Due to the coronavirus pandemic and for other reasons, we used echocardiography where MRI was not available. Dr. Greg Hundley: And so the total number of subjects here was how many? Dr. Andrew Chapman: We recruited 100 patients with a clinical diagnosis of type two myocardial infarction. Dr. Greg Hundley: Very good. And so now, Andrew, what were your results? Dr. Andrew Chapman: It's a really fascinating study, obviously, in my opinion. So we recruited 100 patients with a clinical diagnosis of type two myocardial infarction who had evidence of supplier demand and balance, a raised cardiac troponin concentration and evidence of symptoms and/or signs of myocardial ischemia. So in line with the universal definition criteria. Of 100 patients after undertaking coronary imaging, we reclassified the diagnosis in seven. Dr. Andrew Chapman: In five patients, we found that there was evidence of either plaque rupture or a stent thrombosis. And in two patients, we found evidence of myocarditis and stress cardiomyopathy respectively. The first principle finding is that actually despite careful characterization and really detailed screening, we were correct in 93 of 100 patients and we got the diagnosis wrong in seven. The principle hypothesis related to the prevalence of coronary artery disease and this was, as alluded to, undertaking with invasive and noninvasive imaging. But overall, the prevalence of coronary artery disease was 68% of those with type two myocardial infarction and this was obstructive in 30%. Dr. Andrew Chapman: We also undertook structural imaging as mentioned. We observed evidence of left ventricular systolic dysfunction in 34% of patients, of around a third, and perhaps most surprisingly, although we had a clear diagnosis of myocardial infarction in these patients, we only found imaging evidence of in part pattern late gadolinium enhancement, which is considered the gold standard for its diagnosis of myocardial infarction. We only observed that in 42%, which raises some interesting questions. Dr. Andrew Chapman: One of the principle clinical findings of the study is that these underlying conditions of coronary artery disease and left ventricular impairment, both of which are readily treatable with secondary prevention. These conditions were previously unrecognized in 60% of patients and only one-third were on appropriate evidence-based treatment, which gives me some cause for optimism, that there may be a role here for targeted treatment, which could plausibly, plausibly impact on outcomes. Dr. Greg Hundley: And Andrew, just a clarification point, maybe a subgroup analysis, any differences in your findings in regarding men versus women? Dr. Andrew Chapman: Excellent question. And in most studies of type two myocardial infarction, it's thought that this condition is more prevalent in women than men, but undoubtedly in all observational cohorts, there is selection bias as you will only diagnose a type two myocardial infarction if a clinician requests to test troponin in the first place. In our study, interestingly, we recruited more men than women. We had 56% men and we did not find any differences by sex in our analysis. Dr. Greg Hundley: Well listeners, what an excellent description from Dr. Chapman. A very interesting study. And we now want to turn to one of our editors, guest editors, Dr. Harvey White, and Harvey, we want to thank you for your work here with us at the American Heart Association and Circulation, and you receive many articles to review. What attracted you to this particular article and how do we put in context, these results with others that have been published pertaining to type two myocardial infarction? Dr. Harvey White: Thanks, Greg, it's a pleasure to work for Circulation. This paper is very close to my heart because I introduced the typing system in 2007 and it had minimal support and people said, "Why do we need a typing system? We've got killer class and Canadian class and you've done a troponin release system as well". And people stood up and then I laid out the type one plaque rupture. We know the pathophysiology and we know the treatment. Type two, I'd worked on beta blockers, supply and demand and I thought we should define the pathophysiology and define the treatment. That's 2007, which is 15, 16 years ago. And Andrew's paper is really lovely. As I said, it's close to my heart and he inches things forward. I've written an editorial, which I call "Zooming in on the enigmas of type two MI" and enigma means mystery or it's unclear, uncertain. Dr. Harvey White: And that's for sure we don't have full support for the diagnosis. It's become very practical, used in clinical trials and clinically, but we don't know how to manage it and we don't know how to define the groups. Andrew and colleague study is very nice. It's prospective and it has set out to define the coronary artery disease. I've tried for about 10 years to subdivide type two and to those without coronary disease and those with coronary disease. And you could also have a type C, which hasn't been investigated or unknown. And Andrew has answered one of the enigmas and it's really interesting. Large proportion, normal coronary arteries, diagnosis was changed a little bit based on the finding of thrombus. We're challenged with that finding because all MIs have thrombus at PM and really type one should be ruptured plaque. But Andrew changed the diagnosis in a few where one was an OTC, a marvelous case with marvelous pictures, changed the diagnosis. So I like the study and I like the findings. Thanks. Dr. Greg Hundley: Very nice. Well, Andrew, what a perspective and listeners getting just to listen to Dr. White is really quite exciting for me. Andrew, what do you see as the next study to be performed in this sphere of research? Dr. Andrew Chapman: I think we've gone some way to provide some insights into the underlying pathophysiology of this condition and these coexistent conditions of coronary artery disease and left ventricular impairment, which might increase an individual's susceptibility to a type two myocardial infarction. The question is what can we do about it and does targeted treatment with secondary prevention therapies for coronary disease and treatment for heart failure left ventricular impairment, does that improve outcomes? Dr. Andrew Chapman: The next study for me is clear. The next study for me, needs to be a randomized controlled trial, whereby patients with type two myocardial infarction are randomized to current best practice or risk stratification by a cardiologist with an interest in this condition, followed by targeted investigation for coronary disease and LV impairment and thereafter treatment as appropriate. This will be a trial of a complex intervention. I'm very grateful that we've received funding in Scotland already for this pilot phase of this trial, which we've called Targets Type Two and we'll begin recruitment for that trial in August of this year. Dr. Andrew Chapman: I must acknowledge colleagues in this area are looking at coronary disease and type two myocardial infraction. Professor Derek Chew is leading a study called Act Two, which is already recruiting and that will also provide invaluable information as to the prevalence of coronary disease and the potential benefits of treatment of that coronary disease in patients with this condition. Dr. Greg Hundley: And Harvey. How about your, what is your perspective in terms of the next series of studies perhaps that need to be performed in this space? Dr. Harvey White: There's a number and I like very much, Andrew's suggestion. The study that we're doing is randomizing to angiography or not angiography working with Derek Chew. I think all patients with MI should have coronary angiography. It's simple, it takes about 10 minutes. There's obviously some contraindications, but the information as Andrew has pointed out is really so useful. He found dissection, he found an embolus. Normal coronary arteries that in my view changes the management. Whether you should do an angiogram is very important. Randomization to various treatments. That's important. I would like to get more information about the objective evidence of type two MI, the criteria for low hemoglobin, shortness of breath, low blood pressure, high blood pressure, and so forth. There's a lot to do. As Andrew pointed out, the outcome may be worse than type one that's becoming more common and I think these studies will be very, very important. Dr. Greg Hundley: Very nice well listeners. We want to thank Dr Andrew Chapman as lead investigator and Dr Harvey White as guest editor for bringing us this study using advanced imaging of patients with type two myocardial infarction, which identified coronary artery disease in two-thirds and left ventricular dysfunction in one-third, and also highlighting that unrecognized and untreated coronary or cardiac disease occurs in many patients with type two MI and gives us pause for thought on a series of studies that may be performed in the future. Dr. Greg Hundley: Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. Dr. Greg Hundley: This program is copyright of the American heart association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit AHAjournals.org.
This week, please join author Enrico Ammirati and Guest Editor Stephane Heymans as they discuss the article "Prevalence, Characteristics, and Outcomes of COVID-19–Associated Acute Myocarditis." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-host. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Well, Carolyn, this week's feature on this April 12, we are going to review COVID-19–associated acute myocarditis, looking at the prevalence and the outcomes. But before we get to that feature discussion, how about we grab a cup of coffee and discuss some of the other articles in the issue, and maybe there could be a quiz in there somewhere. Dr. Carolyn Lam: Oh, yikes. Dr. Greg Hundley: But before we get to that quiz, Carolyn, would you like to go first? Dr. Carolyn Lam: I would, and we're starting with a topic that we rarely talk about, it's about neurodevelopmental impairment. We know that it's common in children with congenital heart disease, yet postnatal variables explain only 30% of the variance in outcomes. To explore whether the antecedence for neuro development disabilities might begin in utero, these authors, led by Dr. Rollins from Boston Children's Hospital and Harvard Medical School, analyzed whether fetal brain volume predicted subsequent neuro development outcome in children with congenital heart disease. To do this, the authors studied fetuses with isolated congenital heart disease and social demographically comparable healthy controlled fetuses, all undergoing fetal brain MRI and two year neurodevelopmental evaluation. Dr. Greg Hundley: Ah, Carolyn, wonderful, interesting article that we're taking on here in Circulation. What did this group find? Dr. Carolyn Lam: In children with congenital heart disease, a smaller total brain volume on fetal MRI correlated with worse neurodevelopmental outcome at two years of age, across all domains of development and adaptive function. A predictive model, including total brain volume, along with sociodemographic and medical data, accounted for up to 45% of the variance in neurodevelopmental outcome within the congenital heart disease group. Fetal brain volume was the most consistent predictor of outcomes across neurodevelopmental domains compared with other sociodemographic and medical or surgical variables. Dr. Greg Hundley: Very nice, Carolyn. Well, my first paper comes to us from the world of preclinical science. Okay, Carolyn, we're going to start it with the infamous Carolyn's quiz. Here we go. Dr. Carolyn Lam: Wait a minute, we should put a rule here, no quizzes on preclinical basic science, especially stuff we can't pronounce. Dr. Greg Hundley: Ah, yes, but seems to me, there's a heart failure expert on the team. Always remember, you can phone a friend because we have our wonderful Augie Rivera, our production manager, who is available and you can call on him at any time. Okay, here's the quiz, is Cam Kinase II helpful to cure or harmful to exacerbate heart disease? Dr. Carolyn Lam: Oh goodness, Greg. Okay. Cam Kinase II, I know it's Calcium-calmodulin Kinase II. I know there are different isoforms, and I'm cheating here a bit because last week we talked about targeting CaM Kinase II in heart disease. I'm going to guess harmful, I'm going to guess dealing with something with calcium overload, but I'm sure there's more to the story. Dr. Greg Hundley: Carolyn, getting onto to the article, cardiac ischemia-reperfusion injury really has emerged as an important therapeutic target for ischemic heart disease, the leading cause, as we know, of morbidity and mortality worldwide. Currently, there is no effective therapy for reducing ischemia-reperfusion injury. Calcium II Calmodulin dependent Kinase II, or CaM Kinase II plays, a pivotal role in the pathogenesis of severe heart conditions, including ischemia-reperfusion injury. Therefore, pharmacological inhibition of CaM Kinase II could be an important strategy in the protection against myocardial damage and cardiac diseases. But to date, however, there is no drug targeting CaM Kinase II for the clinical therapy of heart disease. Furthermore, currently, there is no selective inhibitor of CaM Kinase II Delta, the major CaM Kinase II isoform, in the heart. Dr. Carolyn Lam: Wow. What did the authors do? Dr. Greg Hundley: Okay, Carolyn. A small molecule kinase inhibitor library, and a high throughput screening system for kinase activity of CaM Kinase II Delta9, the most abundant CaM Kinase II Delta splice variant in the human heart, were used to screen for CaM Kinase II Delta inhibitors. Using cultured neonatal rat ventricular myocytes and human embryonic stem cell derived cardiomyocytes, as well as in vivo mouse models, in conjunction with myocardial injury induced by ischemia-reperfusion or hypoxia-reoxygenation and CaM Kinase II Delta9 over expression, this team, led by Professor Yan Zhang, from Peking University, sought to investigate the protection of Hesperidin against cardiomyocyte death and cardiac diseases. Dr. Carolyn Lam: Oh, wow. Please tell us, so what happened? Dr. Greg Hundley: Right, Carolyn. Several important findings. First, Hesperidin, the Aurora B kinase inhibitor, with antitumor activity in vitro directly bound to CaM Kinase II Delta and specifically blocked its activation in an ATP competitive manner. Second, Carolyn, functionally, Hesperidin ameliorated both ischemia-reperfusion and over express CaM Kinase II Delta9 induced cardiomyocyte death, myocardial damage, and heart failure in both rodents and human embryonic stem cell derived cardiomyocytes. And then, finally, Carolyn, in an in vivo BALB/C nude mouse model, with xenografted tumors of human cancer cells, Hesperidin delayed tumor growth without inducing cardiomyocyte death or cardiac injury. Dr. Carolyn Lam: Wow. Goodness, Greg, that's impressive. Okay, what's the take home message? Dr. Greg Hundley: Well, Carolyn, these results suggest that Hesperidin is a specific small molecule inhibitor of CaM Kinase II Delta with dual functions of cardioprotective and antitumor effects. These findings not only suggests that Hesperidin is a promising leading compound for clinical therapy of cardiac ischemia-reperfusion injury, and heart failure, but also could provide a strategy for the joint therapy of cancer and cardiovascular disease caused by anti-cancer treatment. Dr. Carolyn Lam: Wow, Greg, that is an amazing summary. Thank you. Well, for my last paper, I'd like to tell you about a study in which authors led by Dr. Lubo Zhang from Loma Linda University in California, and the colleagues, tested the hypothesis that microRNA-210 protects the heart from myocardial ischemia-reperfusion injury by controlling mitochondrial bio energetics and reactive oxygen species flux. Myocardial infarction in an acute setting of ischemia-reperfusion was examined via comparing loss versus gain of function experiments in microRNA-210 deficient and wall type mice. Dr. Greg Hundley: Ah, Carolyn, another really interesting paper from the world of preclinical science. What were the results here? Dr. Carolyn Lam: MicroRNA-210 deficiency induced an ischemic sensitive phenotype and exaggerated acute myocardial infarction and cardiac dysfunction after MI in males in a gender dependent pattern in a murine model of myocardial infarction. The study identified a novel mechanism of MicroRNA-210 targeting mitochondrial glycerol-3-phosphate dehydrogenase in controlling mitochondrial energy metabolism, and reactive oxygen species flux, and improving cardiac function in the setting of acute ischemic-reperfusion injury. Thus, the present findings reveal new insights into the mechanisms and therapeutic targets for treatment of ischemic heart disease. Dr. Greg Hundley: Oh, beautiful descriptions, Carolyn. Well, my next papers come from the mail bag, and there is a great Research Letter from Professor Downing entitled “Critical Illness Among Patients Hospitalized With Acute COVID-19 With and Without Congenital Heart Defects.” Carolyn, there's a second Research Letter from Professor Zhao entitled “Dual Genetic Lineage Tracing Reveals Capillary to Artery Formation in the Adult Heart.” Dr. Carolyn Lam: Nice. There's also an On My Mind paper by Dr. Mintz on “Prioritizing Quad Therapy and the Path Forward in Guideline-Directed Medical Therapy for Patients with Heart Failure with Reduced Ejection Fraction.” Cool, Greg, thank you. Now, let's go to our feature discussion, shall we? Dr. Greg Hundley: You bet. To learn more about the prevalence and outcomes in COVID-19–associated acute myocarditis. Dr. Carolyn Lam: Acute myocarditis is thought to be a rare cardiovascular complication of COVID-19, or is it? Well, we have minimal data available in case reports, but really not a large scale study until today's issue and today's feature paper, which really aims to look at the prevalence, baseline characteristics, in hospital management and outcomes for patients with COVID-19–associated acute myocarditis. Dr. Carolyn Lam: I'm so pleased to have the first author with us, Dr. Enrico Ammirati from Niguarda Hospital in Milano, Italy, as well as our guest editor, Dr. Stephane Heymans from Maastricht University Medical Center in The Netherlands. Welcome, gentlemen. Enrico, thank you, thank you, thank you for this very important study. Could you please tell us what you did and what you found? Dr. Enrico Ammirati: Carolyn, it's a pleasure to be here with you and Stephane. We performed, let's say, large study on myocarditis associated with the COVID-19. That is a multicenter study, including 23 centers in the United States and in Europe. The senior author is Professor Marco [Metra], from Brasia, and the co first author is Dr. Laura Lupi, again, from Brasia. What we have done was to better characterize the prevalence of in-hospital myocarditis among the patients hospitalized with the COVID-19 diagnosis. Dr. Enrico Ammirati: And then, we tried to describe the outcome and the clinical characteristic at presentation. First of all, we define the myocarditis as a definitive or probable. That was based on the presence of cardiac magnetic resonance imaging consistent with myocarditis plus increase in troponin plus presence of symptoms that are compatible with an acute myocarditis. Alternatively, the patients must have a positive endomyocardial biopsy. Dr. Enrico Ammirati: The first result was that among more than 56,000 patients hospitalized in these hospitals, the rough prevalence of myocarditis was around 2.4 among 1000 hospitalized patients. The second main message was that the prognosis, we divided the population, we spitted the population in two groups. Patients with an ongoing and concurrent pneumonia and patient with myocarditis, but without evidence on CT of pneumonia. What we have found it was that among 57% of cases of COVID patients, you can have a myocarditis without pneumonia. So this is an interesting and new finding, and we compare the clinical characteristic of this patient comparing with the patient with the pneumonia. And we found that generally patient with pneumonia were older comparing with the patient with the isolated myocarditis and the prognosis of patients was worse comparing with the patient with just myocarditis. Dr. Enrico Ammirati: The outcome was around, overall, the outcome of this population that had median age of 38 year was an incidence of 6% of death. And if we look at the patient with the concurrent pneumonia, the outcome was worse. Then we have other findings that are of potential interest. And that is, for instance, that in 55% of patients, corticosteroids were used, and that is consistent with the idea that corticosteroids can work in this setting. We have also data on the presence of such Coronavirus, two in the heart, in patient that undergo vital search. And it was just in 21% of cases that underwent genome research in the myocardium. So I would say that these are the main findings of this research. Dr. Carolyn Lam: Oh, wow. First of all, heartfelt congratulations more than fifth, almost 57,000 hospitalized patients with COVID-19 and 23 hospitals across us and Europe. Stefan, you really appreciate that you served as guest editor here. Could you tell us some of your initial reactions, put the findings in context, perhaps? Dr. Stephane Heymans: Yes, yes. For sure. Enrico, indeed, I would like to concur with this congratulations on this beautiful study. It's a lot of work to collect this data and also to try to distinguish myocarditis from all other possible cause of cardiac injury. When I first saw this data, I think, oh, how difficult should be to make a diagnosis of myocarditis. And, of course, increased troponins are often seen in those COVID-19 hospitalized patients. Cardiac MRI is quite a specific for any non-ischemic myopathy. Yeah, I was wondering, so are these cardiac MRI images suggestive of acute myocarditis, but a really specific, sensitive enough to make a definite accurate diagnosis of COVID 19 related myocarditis, or could also be severe illness related to COVID-19 sepsis of pneumonia, give similar images on cardiac MRI? Dr. Enrico Ammirati: Stephane, this is a very good point. We haven't studied so in detail the cardiac injury in patients with the viral pneumonia, with the other viruses, so we cannot say that this kind of cardiac involvement is specific for such Coronavirus too. But what I can say is that this population is a population of highly likely acute myocarditis because if you look at simple clinical characteristics, and you can find that the median age is 38 years. This is the first reassuring a clinical characteristic because if we compare with the age of the population, of the laboratory registry of acute myocarditis we published in 2018 in Circulation, the media age was 36. Dr. Enrico Ammirati: Then, another point in support of our finding is that in the end, we have both present of edema and positive LG in patients with consistent myocarditis on magnetic resonance imaging. So, I know that probably edema can be associated with either other form of myocardial injury that are not necessary so specific for myocarditis. But if you look at troponin increase in this population, the median increase was 55 folds above the upper reference limit, so it was not just a small increase. It was a huge increase in troponin. Dr. Enrico Ammirati: Specifically, in patients that were above 45 years, we have a confirmation that was no coronary artery disease associated, to assure the readers that likely these are myocarditis. But as you said, we cannot be 100% sure about that. And you mentioned an important point, we cannot say that, also, in other form of viral disease, we can have a myocardial injury that can be very similar to myocarditis. Dr. Stephane Heymans: Yes. Thank you so much for your clear answer. It just underscores how sick a COVID-19 can make you because the numbers you're getting is two [in] 1000, you would say, okay, that's a small number, but still, there's so many more patients with a cardiac injury related to COVID-19. Indeed, to put it into context, so common viral myocarditis occurs in one to 10, 100,000, so the COVID-19 related myocarditis is up to 100 times more with your numbers. And of course, the common viral myocarditis, it's at the same age, similar age around 36, means a young, relatively young age. Dr. Stephane Heymans: Indeed, this COVID-19 is probably a trigger in immune and maybe genetic susceptible, young persons had to get myocarditis upon COVID-19 disease. Whereas, the COVID-19 vaccination related myocarditis, which is getting much more media attention, at least, previous months, only occurs in one to five in 100,000 people. And those patients are completely recover and transplant free. Survival is over 99%. To put it in context, it's still quite severe at this COVID-19 related myocarditis. Dr. Carolyn Lam: Thank you so much. Stephane. Dr. Enrico Ammirati: Can I add some comments? First of all, we have to say that these patients that died with myocarditis associated with the COVID-19, died to complication related to ECMO. For instance, we had a patient with a brain hemorrhage, and we had one patient who had a complication related septic shock. So, myocarditis can be something on top of a severe disease. We have a condition that is as background that is quite severe, and we a further complication related to myocarditis, so what we have seen is that, generally, even comparing with the previous Lombardy Registry I referred before the outcome of this patient was worse. Of course, it's very difficult to compare studies that have been performed in different centers during a different time period. But, of course, if you think that most of viral myocarditis are secondary to cold or flu, so the background condition is really mild. Dr. Enrico Ammirati: The main focus is the myocarditis. While in this patient, we have a subpopulation where you have in a great proportion of them, a severe myocarditis associated with a pneumonia. So you have the double component and that can explain why this patient had a worse outcome. Referring to them, vaccination, my thought is that for the first time we have a large vaccine campaign in this range of age, between 15 and 30 years or 35 years, that is the population at higher risk for myocarditis, where we do not generally perform large campaign for vaccination. Dr. Enrico Ammirati: In the end, it can be that we have seen more myocarditis related to vaccination because it was the first time that we vaccinate this kind of population. We have seen something similar with a smallpox vaccination in the military population. And that's the case because for other reason, that are not really related to the health reason, we vaccinated a high-risk population for myocarditis by itself. And we found that smallpox is more associated with myocarditis. Probably, there are, as you said, genetics per count that can explain in some patients an increase risk of myocarditis, but that can be possible that is there is also hormonal or epigenetics phenomena that can explain the higher risk in this population for myocarditis, both for COVID related or for vaccine related. Dr. Stephane Heymans: Ah, yeah. Enrico, could you remind me, was this incident of prevalence of COVID-19 myocarditis more prevalent in male patients compared to female when correcting for the background numbers? Dr. Enrico Ammirati: In our population, the main population was exactly was about 60%. There was just a slight increase in the number of cases in the male population, but it was not such a large prevalence as you expect in, let's say, uncomplicated myocarditis, where you can find an 80% of male prevalence or in vaccine. Dr. Stephane Heymans: Indeed. In the common or the vaccine related myocarditis, it's mainly young male, hetero sex, hormonal factors are being involved, so probably, as you say, these COVID-19 patients have a change in their immune background. And some of those, might some of those also have already background cardiomyopathy or myocarditis, maybe cardiomyopathy, that was not known yet. And then with the COVID-19 might have developed a clinical myocarditis/cardiomyopathy. Dr. Enrico Ammirati: When we look at the endostolic diameter of the left ventricle, I can say that the diameter was in the normal range, so that can support the idea that generate this patient did not have a previous dilated cardiomyopathy, but I cannot say that this patient had a known dilated cardiomyopathy before this event. Dr. Carolyn Lam: You know, once in a while, Augie, I get to do some of these interviews, and it just takes off on its own. And I love it. And there's nothing I need to do except to sit and listen, and to be grateful that you are publishing this and having such a lovely discussion on this podcast. Thank you, both of you. And, if I could, just very quickly, do you have any take home clinical messages now, from what you've seen, for someone who may be managing one of these COVID-19 patients and suspecting anything? Dr. Enrico Ammirati: Can I add that, in the end, what I can, say based on this research, is that likely myocarditis associated with COVID-19 is worse compared with myocarditis associated to vaccine. So even if we see that probably the prevalence is, again, high year with COVID-19, but the most important point is that it's even worse with myocarditis is associated with COVID-19 comparing with the vaccine, so please get the vaccination. Dr. Carolyn Lam: Thank you. And you've been listening to Circulation on the Run. From Greg and I, thank you for joining us today. I'm sure you're so grateful, and have learned so much, as I have. And don't forget to tune in again, next week. Dr. Greg Hundley: This program is copyright of the American Heart Association, 2022. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
This week, please join author Zdenka Pausova and Associate Editor Svati Shah as they discuss the article "Circulating Metabolome and White Matter Hyperintensities in Women and Men." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your cohosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, have you ever wondered what white matter hyperintensities in a brain are made of? Well, guess what? The feature discussion is going to give us a little clue. Believe it or not from the circulating metabolome, interesting, huh? Well, I'm going to keep you in suspense, as we first discuss other papers in the issue. And I want to go first, may I? Dr. Greg Hundley: Absolutely, but let's all grab a cup of coffee. Dr. Carolyn Lam: All right. You got yours. And here goes. This first paper reviews the results of endovascular aneurysm repair in patients from the Japanese Committee for Stent Graft Management registry, to determine the significance of persistent type II endoleak and the risk of late adverse events, including aneurysm sac enlargement. Dr. Greg Hundley: Ah, Carolyn, a very clinically relevant question. So what did this study show? Dr. Carolyn Lam: Of more than 17,000 patients who underwent endovascular aneurysm repair for abdominal aortic aneurysm from 2006 to 2015, 29% had persistent type II endoleak. The cumulative incidence rates of abdominal aortic aneurysm related mortality, rupture, sac enlargement, and reintervention were higher in patients with persistent type II endoleak. Specifically, the cumulative incidence rates of rupture and abdominal aortic aneurysm related mortality increased to 2% at 10 year follow up, which is dissimilar to the previously reported frequency of only about 1%. Cox regression analysis revealed older age, female sex, proximal neck diameter, and chronic kidney disease as independent, positive correlates of sac enlargement. Dr. Carolyn Lam: So these wonderful results are from Dr. Hitoshi Matsuda and colleagues from the National Cerebral and Cardiovascular Center in Osaka Japan, and really suggests that persistent type II endoleaks are not always benign. Dr. Greg Hundley: Beautiful summary, Carolyn. Well, my paper comes from the world of pre-clinical science. And Carolyn, in most eukaryotic cells, the mitochondrial DNA is uniparenterally transmitted and present in multiple copies derived from the clonal expansion of maternally inherited mitochondrial DNA. All copies are therefore, nearly identical or, as we would call homoplasmic. Dr. Greg Hundley: Now Carolyn, the presence of more than one mitochondrial DNA variant in the same cytoplasm can arise naturally or as a result from new medical technologies aimed at preventing mitochondrial genetic diseases and improving fertility. The latter is called divergent non-pathological mitochondrial DNA heteroplasmy, or DNPH. Dr. Greg Hundley: Now Carolyn, these investigators led by Professor Jose Enriquez from the Centro Nacional de Investigaciones Cardiovasculares hypothesized that DNPH is maladaptive and usually prevented by the cell. Dr. Carolyn Lam: Wow, that's really interesting, investigations from the world of preclinical science. What did the investigators find? Dr. Greg Hundley: Right, Carolyn. So, the investigative team engineered and characterized divergent non-pathological mitochondrial DNA heteroplasmy, or DNPH, as we've talked about before, mice throughout their lifespan. The authors found that DNPH impair mitochondrial function with profound consequences in critical tissues that did not resolve heteroplasmy, particularly within cardiac and skeletal muscle. Progressive metabolic stress in these tissues led to severe pathology results, including pulmonary hypertension and heart failure, skeletal muscle wasting, frailty, and premature death. And finally, Carolyn, symptom severity was strongly modulated by the nuclear context. Dr. Greg Hundley: So in conclusion, Carolyn, these findings suggest that medical interventions that could generate divergent non-pathological mitochondrial DNA heteroplasmy, or DNPH, so to address potential incompatibility between donor and recipient mitochondrial DNA. Dr. Carolyn Lam: Oh wow. That is fascinating. Well guess what? My next paper is also about mitochondria, but this time looking at the role of the mitochondrial calcium uniporter. So we know that calcium is a key regulator of energy metabolism and impaired calcium homostasis damages mitochondria, resulting in cardiomyocyte death, pathological hypertrophy, and heart failure. Dr. Carolyn Lam: This study by Dr. Wang from University of Washington and colleagues investigated the regulation and the role of the mitochondrial calcium uniporter in chronic stress induced pathological cardiac remodeling. In a series of elegant experiments in the mitochondrial calcium uniporter knockout or transgenic mice infused with isoproteronol, the authors found that the mitochondrial calcium uniporter is up regulated in the stressed heart to orchestrate mitochondria sarcoplasmic reticulum, and cytosolic calcium handling, preventing cytosolic calcium overload induced cardiomyocyte death. Dr. Carolyn Lam: Lack of mitochondrial calcium uniporter mediated mitochondrial calcium uptake is detrimental. Whereas, transgenic over expression is beneficial to the heart during chronic beta adrenergic stimulation. The nuclear translocation of calcium/ calmodulin kinase II delta beta via calcineurin mediated dephosphorylation of serine 332 activates CAMP response element binding protein to promote mitochondrial calcium uniporter gene expression in adult cardiomyocytes. Dr. Greg Hundley: Well, Carolyn, what's the take home here? What are the clinical implications? Dr. Carolyn Lam: Ah, thought you might ask. Well, this study indicates that enhancing mitochondrial calcium uptake could be a new approach to prevent chronic beta adrenergic stimulation induced heart remodeling. Targeting this cam kinase two delta beta KREB mitochondrial calcium uniporter pathway could be a therapeutic option for pathologic cardiac remodeling associated with chronic adrenergic stress. Dr. Greg Hundley: Excellent description, Carolyn, and thank you for walking us through that wonderful paper. Well, we've got some other papers in the issue and from the mail bag, Professor Lusis has a Research Letter entitled Identification of DNA Damage Repair Enzyme, ASK II as Causal for Heart Failure with Preserved Ejection Fraction. And Carolyn there's a cardiovascular case series from Professor Barrett entitled, “The Unrepairable Infant Mitral Valve, an Unexpected Case of Decompensated Heart Failure.” Dr. Carolyn Lam: Interesting. There's an exchange of letters between Doctors Matrougui and Wang regarding the article, “Integrated Stress Response Couples Mitochondrial Protein Translation with Oxidative Stress Control” and a Perspective piece by Dr. Fatkin on “Fishing for Links between Omega-3 Fatty Acids and Atrial Fibrillation.” Wow. Super cool. Greg, let's go on now to a feature discussion, shall we? Dr. Greg Hundley: You bet. Dr. Carolyn Lam: For our feature discussion today, we are talking about white matter hyperintensities. Now that's the most common brain imaging marker of small vessel disease. That may be known, but there's a lot more to it. For example, what are they made of? Well, you're going to so enjoy today's feature paper, and I'm so proud to have the corresponding author with us, Dr. Zdenka Pausova from Hospital for Sick Kids in Toronto, Canada, as well as our associate editor, Dr. Svati Shah from Duke University. So welcome ladies. And Zdenka, if I could start with, could you explain the rationale for your study and what you did? Dr. Zdenka Pausova: Yeah. Thank you. Thank you for having me. Well, we were thinking that it is important to know what the metabolic variables that associate with white matter hyperintensities might be, simply because we know that there are other studies that have shown that whatever circulates in blood is in some way related to brain health. For example, different lipids associated with Alzheimer Disease, cognitive functioning and with structural properties of the brain. So we were wondering what the metabolics that are associated with white matter hyperintensities might be, simply because we would like to know a little bit more about the pathogenesis of the disease, because that's what metabolomic profiling can provide. And also if one can identify biomarkers that potentially could be used in the clinical setting. Dr. Carolyn Lam: Wow. Thank you. And Zdenka, this may be a very basic question, but we hear a lot about the metabolome and sometimes it's not very clear what metabolome profiling actually is. And could you just say a little bit about the technique and your study population and then your findings? Thanks. Dr. Zdenka Pausova: Yes. Sure. So we actually studied over 9,000 individuals from eight different population based studies and all of those individuals had metabolomic assays done with two main platforms. It's mass spectrometry and nuclear magnetic spectroscopy. Mostly these platforms are actually commercially available and altogether across all platforms, there were over 2,200 different metabolites. And from those we could study about 1200 that we had at least in two populations. And what the metabolites are, these are different metabolites of lipids, sugar, proteins, amino acids that people put on those platforms or that designers put on the platforms, in order to test some of their hypotheses, that they were actually these metabolites of interest for different sorts of diseases, including cardiovascular and cerebrovascular disease. Dr. Carolyn Lam: Wow. So this is really large scale, massive, big data, if I may, and if I'm not wrong, it's the first large scale study to identify circulating metabolomic measures associated with white matter hyperintensities. So could you please summarize the main findings? Dr. Zdenka Pausova: Well, overall we actually found that there were 416 metabolites that were nominally associated with white matter hyperintensities, but as it is in epidemiology, you have to correct for multiple comparisons. So when we did DR correction, there were only 30 variables associated with white matter hyperintensities. And when we wanted to check whether those associations are independent of the risk factors for white matter hyperintensities, such as hypertension, type two diabetes, smoking, obesity, we actually ended up with seven markers, seven metabolites that were significantly associated in the fully adjust model. Dr. Zdenka Pausova: And the main one was actually a derivative of amino acid hydroxyphenol that probably is a marker of ischemia in the brain. And what actually I am coming to is, and one of the main findings was, that many of those metabolites were associated with white matter hyperintensities in a sex specific manner. That is that they were detected in the pool sample, but essentially the signal came from only one of the sexes. And so this one that was the most significant was detected only in males essentially, and not really in females. Dr. Zdenka Pausova: And that I think is an interesting, one of the most interesting findings that we can expect that there are really sex specific pathways, biochemical pathways, that accompany white matter hyperintensities. Dr. Carolyn Lam: Wow. Zdenka, thank you so much. I have to bring Svati in right now to share some perspective, Svati, especially to put these findings into context, please. Dr. Svati Shah: Yes. Dr. Pausova, really wonderful paper. This is an incredible study, if you think about it. The largest scale study that really is trying to understand metabolic by biomarkers, but the biomarkers actually tell us about the potential biology of what's going on with these white matter hyperintensities. We know that these hyperintensities in the brain are associated with increased risk of stroke, increased risk of cognitive decline, but we don't really understand stand what the risk factors are. There's been some studies suggesting that there's genetic risk factors, but this is really the first large scale study to say, "Hey, what's in the blood that we can measure?" And just to be clear, these technologies are measuring these biomarkers that are very, very, very low levels in the blood, really granular snapshot of what's going on with the human being. Dr. Svati Shah: And by looking at these blood markers that the authors were able to find biomarkers that are associated with these brain abnormalities, but really highlighting some of the important biology as Dr. Pausova started to talk about. So I think what it gets us to is we get to have our cake and eat it too. We get to learn about biomarkers that might have clinical utility, but we also have discovered, they've discovered new biology that could lead to new therapies, for example, and a better understanding of the mechanisms of why some people develop these hyperintensities as they age. And some people do not. Dr. Carolyn Lam: Wow, Svati, you put that so eloquently and just to put it out there for everyone, that significant metabolite hydroxyphenol pyruvate explain 14% of the variants of white matter hyperintensity volumes in males. Whereas, the proportion of variants explained by hypertension is only 1% or type two diabetes is only 1 to 3%, or smoking is even less than 0.1%. So this is, as you said, Svati, it's a significant discovery as well. Zdenka, though, how do we apply this clinically? Dr. Zdenka Pausova: Well, it could be a marker that is measured in circulation and it is a marker that can be measured in blood and can indicate early stages of white matter hyperintensities. But I think before we get there, it would be of high value to actually carry out some longitudinal studies, because it would be really interesting to know if it is an early marker before the white matter hyperintensities extent is enlarged. And so that would one thing. But other than that, I think if that would be the case, we can just measure it in blood and see how predictable it is. Dr. Carolyn Lam: Can I ask what about the women? Did anything predict it in women? Dr. Zdenka Pausova: That's a good question. There was only actually one variable. To our surprise, only one variable that was significantly associated with white matter hyperintensities in women. And it is really surprising because the sample size was the same. The extent, the volume of white matter hyperintensities was quite similar. They were of similar age, similar adiposity. So there were no huge differences, yet we could not actually detect too many metabolized associated with white matter hyperintensities in women. Really surprising. And I don't have a good answer for it now. Dr. Carolyn Lam: Wow. Thank you. Svati, did you have further thoughts on the clinical applications and implications of these tremendous data? Dr. Svati Shah: Yeah. I think the ability to have a biomarker as Dr. Pausova nicely articulated that would potentially prevent people from having to get an MRI. And we would be able to identify people hopefully at an earlier stage in the process. In this lovely study, they were looking at biomarkers in people who already had the hyperintensities. I think the next step as Dr. Pausova outlined to be able to identify whether these predict high risk people who will develop them in the future and then try to target therapies. A potential advance in precision medicine in the neurologic space, that we could use this biomarker to say, "You need this particular medication." Dr. Svati Shah: Some of the biomarkers that Dr. Pausova's group discovered were actually just cholesterol measures. So maybe we need to be instituting more aggressive cholesterol therapies in these patients who are at high risk. I'm not saying we can do that yet, but these provocative results suggest that this could lead to a more personalized approach to high risk individuals who may have consequences and develop these white matter hyperintensities. Dr. Carolyn Lam: And Zdenka, did you have anything to add to that? Dr. Zdenka Pausova: Perhaps one interesting aspect of the study that I actually was nicely surprised at the end of the study that the markers, one could the different lipids or the different derivatives of amino acids, the literature provided actually a possible pathways, how those could be involved in the development of white matter hyperintensities. Some of them actually, we could possibly link to impairment of myelination of a neuronal axons, or actually the axons themselves could be the metabolized could reflect damage of those axons. Dr. Zdenka Pausova: And also, one suspicious pathway or one pathway that is suspected to be big part of the development of white matter hyperintensities is the disruption of blood brain barrier and some of the markers could be actually linked to that vascular dysfunction. Dr. Carolyn Lam: Aw, that's wonderful. Thank you so much, Zdenka, for publishing this beautiful work with us in Circulation. And thank you, Svati, for taking this paper through and inviting this beautiful editorial. In fact, it quite summarizes our discussion. It's entitled, What Turns White Matter White? Metabolic Clues to the Origin of Age-Related White Matter Hyperintensities and it's by Dr. Eric Smith from University of Calgary and I invite everyone to read this. Dr. Carolyn Lam: So thank you once again for joining us today on Circulation on the Run. From Greg and I, it's been wonderful having you. Don't forget to join us again next week. Dr. Greg Hundley: This program is copyright of the American Heart Association 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.
© 2020-2025 Ivy Podcast Discovery LLC
