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Each 15-minute podcast begins with an overview of the issue’s contents and main take-home messages for busy clinicians on the run. This is followed by a deep dive into a featured article of particular clinical significance: views will be heard from both author and editor teams for a “behind the scen…

Carolyn Lam, MBBS, PhD

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    Circulation January 24, 2023 Issue

    Play Episode Listen Later Jan 23, 2023 29:55

    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

    Circulation January 17, 2023 Issue

    Play Episode Listen Later Jan 17, 2023 26:08

    Please join author Pieter Martens and Associate Editor Justin Grodin as they discuss the article "Decongestion With Acetazolamide in Acute Decompensated Heart Failure Across the Spectrum of Left Ventricular Ejection Fraction: A Prespecified Analysis From the ADVOR Trial." Dr. Greg Hundley: Welcome listeners to this January 17th issue of Circulation on the Run. And I am Dr. Greg Hundley, Director at the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Peder Myhre: And I'm Dr. Peder Myhre from Akershus University Hospital and University of Oslo, in Norway. And today, Greg, we have such an exciting feature paper. It comes to us from the ADVOR trialists. And the ADVOR trial examined the effect of acetazolamide in acute decompensated heart failure. And in this paper we're going to discuss how that treatment effect was across the left ventricular ejection fraction, across the spectrum. Greg, what do you think? Dr. Greg Hundley: Oh, wow. Sounds very interesting. But we might have some other articles in the issue. How about we grab a cup of coffee and Peder maybe this week, I'll go first and we'll start with preclinical science. How about that? Dr. Peder Myhre: Let's do preclinical science, Greg. Dr. Greg Hundley: Well, Peder, this particular paper focuses on the relationship between cardiac fibroblasts and cardiomyocytes. Remember that myocytes sit on a lattice of network of fibroblasts. And when the myocytes die, the fibroblasts then proliferates, secrete collagen and form this thick scar. Now, if we're going to try to regenerate, how are we going to get myocytes to get back into that thick scar when there's really a complete absence? And so as adult cardiomyocytes have little regenerative capacity, resident cardiac fibroblasts synthesize extracellular matrix, post myocardial infarction to form fibrosis, leading to cardiac dysfunction and heart failure. And therapies that can regenerate the myocardium and reverse fibrosis in the setting of a chronic myocardial infarction are lacking. Now, these investigators led by Professor Masaki Ieda from University of Tsukuba, were going to evaluate this process. The overexpression of cardiac transcription factors, including Mef2c, Gata4, Tbx5, Han2, all combined as MGTH. They can directly reprogram cardiac fibroblasts into induced cardiomyocytes and improve cardiac function in and under the setting of an acute myocardial infarction. However, the ability of an in vivo cardiac reprogramming to repair chronic myocardial infarction with established scars, well, that is really undetermined. Dr. Peder Myhre: Oh, what a wonderful introduction, Greg. And the way you described to us how cardiomyocytes and fibroblasts interact was really fascinating. Thank you. And now let's hear what the authors found and don't forget the clinical implications. Dr. Greg Hundley: Thanks, Peder. So these authors developed a novel transgenic mouse system where cardiac reprogramming and fibroblasts lineage tracing could be regulated spatiotemporally with tamoxifen treatment to analyze in vivo cardiac reprogramming in the setting of chronic MI. Then with this new model, the authors found in vivo cardiac reprogramming generates new induced cardiomyocytes from resident cardiac fibroblasts that improves cardiac function and reduces fibrosis in chronic myocardial infarction in mice. Wow. And additionally, they found that overexpression of cardiac reprogramming factors converts profibrotic cardio fibroblasts to a quiescent state, and that reverses fibrosis in chronic myocardial infarction. And therefore, Peder, direct cardiac reprogramming may be a promising therapy for chronic ischemic cardiomyopathies and heart failure. Really exciting work, converting scar tissue to actual functional cardiomyocytes. Dr. Peder Myhre: That was such a fantastic summary, Greg, and a very interesting paper. And I'm now going to take us back to clinical science and epidemiology. Because Greg, we all know that social and psychosocial factors are associated with cardiovascular disease risk. But the relative contributions of these factors to racial and ethnic differences in cardiovascular health has not been quantified. So these authors, led by the corresponding author, Nilay Shah from Northwestern University Feinberg School of Medicine in Chicago, used data from NHANES to examine the contributions of individual level social and psychosocial factors to racial and ethnic differences in population cardiovascular health. And that was measured by something called the cardiovascular health score, CVH score, which ranges from zero to 14, and it counts for diet, smoking, physical activity, body mass index, blood pressure, cholesterol, and blood glucose. Dr. Greg Hundley: Wow, really interesting, Peder. So what did they find here? Dr. Peder Myhre: So Greg, among males, the mean cardiovascular health score was 7.5 in Hispanic, 8.7 in non-Hispanic Asian, 7.5 in non-Hispanic black, and 7.6 in non-Hispanic white adults. And the authors found that the education explained the largest component of cardiovascular health differences among males. And now what about females? In females, the mean score was 8.0 in Hispanic, 9.3 in non-Hispanic Asian, 7.4 in non-Hispanic black, and 8.0 in non-Hispanic white adults. And for women, education explained the largest competence of cardiovascular health difference in non-Hispanic black. And place of birth, and that is US born versus born outside the US, explained the largest component of cardiovascular health difference in Hispanic and non-Hispanic Asian females. So Greg, the authors conclude that education and place of birth conferred the largest statistical contributions to the racial and ethnic differences in cardiovascular health among US adults. Dr. Greg Hundley: Very nice, Peder. What a beautiful description and outline that so well highlighting the differences in men versus women. Well, now we're going to turn back to the world of preclinical science, listeners. And we will continue with the paper by Dr. Amit Khera from Verve Therapeutics. Now, Peder, VERVE-101, this is an investigational in vivo CRISPR base editing medicine designed to alter a single DNA base in the PCSK9 gene. And that permanently turns off hepatic protein production and thereby, durably lowers LDL cholesterol. In this study, the investigators tested the efficacy, durability, tolerability, and potential for germline editing of VERVE-101 in studies of non-human primates and also in a murine F1 progeny study. Dr. Peder Myhre: So more on PCSK9s, and this time CRISPR technology. Very exciting. Greg, what did they find? Dr. Greg Hundley: Right, Peder. So VERVE-101 was well tolerated in non-human primates and led to, listen to this, an 83% lower blood PCSK9 protein and 69% lowering of LDL-C with durable effects up to 476 days following the dosing. These results have supported initiation of a first inhuman clinical trial. That's what needs to come next in patients with heterozygous familial hypercholesterolemia and atherosclerotic cardiovascular disease. Wow. Dr. Peder Myhre: Even greater reductions from this therapy on PCSK9 than the previous PCSK9 inhibitor therapies. Wow. Okay, Greg, and now we go from one fascinating study to another. And this time we actually have the primary results from a large randomized clinical trial, Greg. Isn't that exciting? Dr. Greg Hundley: Yes. Dr. Peder Myhre: And this paper describes the primary results of a trial testing in Indobufen versus aspirin on top of clopidogrel in patients undergoing PCI with drug-eluting stent DES who did not have elevated troponin. So that is patients without mycardial infarction. And in fact, fact, this is the first large randomized control trial to explore the efficacy and safety of aspirin replacement on top of P2Y12 inhibitor in patients receiving PCI with death. And Greg, I suppose you like I wonder what Indobufen is, and I just learned that that is a reversible inhibitor of platelet Cox-1 activity and it has comparable biochemical and functional effects to dose of aspirin. And previous data indicate that Indobufen could lessen the unwanted side effects of aspirin and that includes allergy intolerance and most importantly, aspirin resistance, while it retains the antithrombotic efficacy. Dr. Greg Hundley: Wow, Peder. Really interesting and great explanation. Indobufen. So how did they design this trial and what were the primary results? Dr. Peder Myhre: So Greg, the investigators of this trial, called OPTION, led by corresponding authors, Drs. Ge, Quian, and Wu from Fudan University in Shanghai, randomized 4,551 patients from 103 center to either indobufen based DAPT or conventional, and that is aspirin based DAPT for 12 months after DES implementation. And the trial was open label and with a non-inferiority design, which is important to keep in mind. And the primary endpoint was a one year composite of cardiovascular death, non-fatal MI, ischemic stroke, definite or probable stent thrombosis or bleeding, defined as BARC criteria type 2, 3, or 5. And now Greg, the primary endpoint occurred in 101, that is 4.5% of patients in the indobufen based DAPT group compared to 140, that is 6.1% patients, in the conventional DAPT group. And that yields an absolute difference of 1.6%. And the P for non-inferiority was less than 0.01. And the hazard ratio was 0.73 with confidence intervals ranging from 0.56 to 0.94. And Greg, the occurrence of bleeding was particularly interesting and that was also lower in the indobufen based DAPT group compared to the conventional DAPT group. And that was 3.0% versus 4.0% with the hazard ratio of 0.63. And that was primarily driven by a decrease in BARC type two bleeding. So Greg, the authors conclude that in Chinese patients with negative cardiac troponin undergoing DES implementation, indobufen plus clopidogrel DAPT compared with aspirin plus clopidogrel DAPT significantly reduced the risk of one year net clinical outcomes, which was mainly driven by reduction in bleeding events without an increase in ischemic events. Dr. Greg Hundley: Very nice, Peder. So another reversible inhibitor of platelet COX-1 activity, indobufen. And seems to be very, have high utility in individuals of Chinese ethnicity and Asian race. Well, perhaps more to come on that particular drug. Peder, how about we dive into some of the other articles in the issue? And I'll go first. So first, there's a Frontiers article by Professor Beatty entitled “A New Era and Cardiac Rehabilitation Delivery: Research Gaps, Questions, Strategies and Priorities.” And then there's a Research Letter by Professor Zuurbier entitled, “SGLT-2 inhibitor, Empagliflozin, reduces Infarct Size Independent of SGLT-2.” Dr. Peder Myhre: And then Greg, we have a new ECG challenge by Drs. Haghighat, Goldschlager and Oesterle entitled, “AV Block or Something Else?” And then there is a Perspective piece by Dr. Patrick Lawler entitled, “Models for Evidence Generation During the COVID-19 Pandemic: New Opportunities for Clinical Trials in Cardiovascular Medicine.” And Greg, there's definitely so much to learn from all the research that has been done through the pandemic. And finally, we have our own Molly Robbins giving us Highlights from the Circulation Family of Journals. And first, there is a paper describing the characteristics of postoperative heart block in patients undergoing congenital heart surgery described in Circulation: Arrhythmia Electrophysiology. Next, the impact of socioeconomic disadvantages on heart failure outcomes reported in Circulation: Heart Failure. Then there is social and physical barriers to healthy food explored in circulation, cardiovascular quality and outcomes. And then there is the association of culprit-plaque morphology with varying degrees of infarct, myocardial injury size reported in Circulation: Cardiovascular Imaging. And finally, the impact of optical coherence tomography on PCI decisions reported in circulation cardiovascular interventions. Dr. Greg Hundley: Fantastic, Peder. Well, how about we get off to that feature discussion? Dr. Peder Myhre: Let's go. Dr. Mercedes Carnethon: Well, thank you and welcome to this episode of the Circulation on the Run Podcast. I'm really excited today to host this show. My name is Mercedes Carnethon. I'm an associate editor at Circulation and Professor and Vice Chair of Preventive Medicine at the Northwestern University Feinberg School of Medicine. I'm really excited to learn from the lead author of a new study on decongestion with Acetazolamide and acute decompensated heart failure across the spectrum of LV ejection fraction. And I've got the lead author with me today, Pieter Martens, as well as my colleague and associate editor Justin Grodin, who handled the paper. So I'd love to start off with just welcoming you, Dr. Martens. Dr. Pieter Martens: Thank you for having me. It's a pleasure to be here today. Dr. Mercedes Carnethon: Yes. And thank you so much for submitting your important work to the journal, Circulation. I'd love to start to hear a little bit about what was your rationale for carrying out this trial and tell us a little bit about what you found. Dr. Pieter Martens: So the ADVOR trial was a double blind placebo controlled randomized trial, which was performed in Belgium. And it set out to assess the effect of acetazolamide in acute decompensated heart failure and this on top of standardized loop diuretic therapy and patients with heart failure. And the goal of the current analysis was to assess whether the treatment effect of acetazolamide in acute heart failure differs amongst patients with a different ejection fraction at baseline at randomization. So we looked specifically at patients with heart failure, reduced, mildly reduced and preserved ejection fraction to determine whether acetazolamide works equally well in those patients. Dr. Mercedes Carnethon: Well, thank you so much. Tell me a little more. What did you find? Did your findings surprise you? Dr. Pieter Martens: All patients that were randomized in the ADVOR trial, we registered a baseline left ventricular ejection fraction at baseline. And what we saw was at the multiple endpoints that we collected in the ADVOR trial, that randomization towards acetazolamide was associated with a pronounced and preserved treatment effect. And different endpoints that we looked at was a primary endpoint which was successful, which is an important endpoint, which we all strive towards in acute decompensated heart failure. And we saw that irrespective of what your baseline ejection fraction was, that randomization towards acetazolamide was associated with a higher odds ratio for having successful decongestion. And also looking at other endpoints which we find important in the treatment of patients with acute compensated heart failure, such as renal endpoints such as the diuresis, the amount of urine that they make, or the natruresis, the amount of sodium that they excrete, we again saw that randomization towards acetazolamide was associated with a higher treatment effect, so more diuresis, more natruresis, which was not effective, whether you had heart failure, reduced, mildly reduced or preserved eject fraction. We did see a slight increase in the creatinine, which was a little bit more pronounced in patients with heart failure with reduced ejection fraction. Dr. Mercedes Carnethon: Thank you so much for that excellent summary. I'm an epidemiologist, so I'm certainly aware that of the cardiovascular diseases and their changes over time, heart failure is one that is going up over time and affecting more of the population. So I know I really enjoyed hearing about an additional therapy that helps to improve quality of life and improve clinical outcomes in individuals who are experiencing heart failure. And I'm really curious as I turn to you, Justin, what attracted you to this particular article and why did you find it to be such a good fit for our audience here at Circulation? Dr. Justin Grodin: Well, Mercedes, I mean, I think you hit the nail on the head with your comment. And clearly when we look at Medicare beneficiaries in the United States, hospitalization for decompensated heart failure is the number one or most common cause for hospitalization. And up to this time, we really haven't had any multi-center randomized control clinical trials that have really informed clinical care with a positive result or a novel strategy that says, "Hey, this might be a better way to treat someone in comparison with something else." And so when we have a clinical trial like ADVOR, one of the crucial things that we want to understand is how does this work and does it work for everybody? And now when we look at the population hospitalized with heart failure, we know that approximately half of them have a weak heart or low ejection fraction, and the other half have a stiff heart, a normal ejection fraction. And so since we've got this 50/50 makeup, it is a crucially important question to understand if we have an important study like ADVOR, does this apply? Are these benefits enjoyed by all these individuals across the spectrum? Dr. Mercedes Carnethon: Thank you so much for really putting that in context. And I believe you had some additional questions for Dr. Martens. Dr. Justin Grodin: Yes. Yeah, thank you. So Pieter, I mean obviously this was a terrific study. One question I had for you guys is, you and your colleagues and the ADVOR research team is whether you had expected these results. Because we know at least historically, that there might be different cardiorenal implications for individuals that have a weak heart or heart failure with reduced ejection fraction in comparison with a stiff heart or heart failure with preserved ejection fraction. Dr. Pieter Martens: Thank you for that comment. And thank you also for the nice feedback on the paper. I think we were not really completely surprised by the results. I think from a pathophysiologic perspective, we do wonder whether heart failure with reduced ejection fraction from a kind of renal perspective is different from heart failure with preserved ejection fraction. Clearly, there are a lot of pathophysiological differences between heart failure with reduced, mildly reduced and preserved ejection fraction. But when it comes to congestion and acute heart failure, they seem to behave, or at least similarly in terms of response to acetazolamide, which was very interesting. We do think there are neurohormonal differences between heart failure reduced ejection fraction, preserved ejection fraction. But at least how acetazolamide works seems relatively unaffected by the ejection fraction. Dr. Justin Grodin: And Pieter, another question that comes to mind, and this is getting a little bit technical, but there have been studies that have shown that people that present to the hospital with decompensated heart failure, that have HFpEF, have a very different perhaps congestion phenotype where they might not have as much blood volume expansion. And so I, for one, was pretty curious as to how these results were going to play out. And I wonder what your thoughts are on that, or maybe that's perhaps more niche and less widely applicable than what you observed. Dr. Pieter Martens: Now, I can completely agree that when we are thinking about congestion, the congestion itself is a sort of pressure based phenomenon. And the pressure based phenomenon is based on what your volume is and the compliance within your cardiovascular system. But I think one of the important things to remember is that how we enrolled patients in the ADVOR trial was that we enrolled patients who had clear signs of volume overload. Remember, we used a volume score to assess clinical decongestion or actually getting rid of the volume. Volume assessment isn't really necessarily a pressure based assessment. And pressures might be the genesis of elevated pressures might be different amongst heart failure with reduced versus preserved ejection fraction. But what was really clear was that all these patients were volume overloaded. And when you think about the volume axis, then it's really about getting rid of that additional sodium, water, and that's where really acetazolamide works. So I do think we differ a little bit from historical acute decompensated heart failure trials in which they sometimes use signs and symptoms of more congestion, a pressure based phenomenon, where our endpoint was truly at volume endpoint. And we do believe that diuretics work really on a volume component of heart failure. Dr. Mercedes Carnethon: Thank you so much, especially for explaining that in a way that even non-clinicians such as myself can understand the potential implications. A big picture question that I have, and I really enjoy these discussions because they give us an opportunity to speculate beyond what we read in the paper. And that question is we do clinical trials and we identify effective therapies. And one of the bigger challenges we often face is getting those therapies out to the people who need them. Do you perceive any barriers in uptake of the use of acetazolamide in clinical practice? Dr. Pieter Martens: That's an excellent question. So one of the, I think beauties about acetazolamide is that this drug has been on the market for about 70 years. So I think everybody has access to it. This is not a novel compound which needs to go through different steps of getting marketing approval and getting a sort of reimbursement before it becomes available in clinical practice. And in theory, everybody should have access to this relatively cheap agent and can use it in its clinical practice. And I think it was very interested when we came out with the initial paper. I think already the day afterwards, we were getting messages from across the world that people have been using acetazolamide. So I think it is an agent which is available in current clinical practice and should not be too many barriers to its current implementation and clinical practice. Dr. Mercedes Carnethon: Well, that's fantastic to hear. So I hope Justin, that you will certainly help to ring the bell to get the information out about this wonderful study. I do want to turn to you, Pieter, to find out whether or not there are any final points that you didn't have an opportunity to discuss with us today. Dr. Pieter Martens: Think some of the other end points we didn't discuss were the effect, for instance, on length of stay. I think length of stay is a very important endpoint because hospital admissions, like Justin said, heart failure is the number one reason why elderly patients are being admitted. And just shortening the length of stay from a financial perspective might be important. So it was also very interesting to see that the use of acetazolamide in the study also translated into a shorter length of stay, which was also was unaffected, whether you had heart failure, reduced, mildly reduced or preserved ejection fraction, Dr. Mercedes Carnethon: Well, I certainly know people appreciate being in their own homes and being able to discharge is certainly a major benefit. So thank you so much for sharing that final point. I really want to thank you so much for a stimulating discussion today. I know that I learned a lot from you, Pieter, and the hard work of your research team as well as from you, Justin, for putting these findings in context and really helping our listeners and the readers of our journal understand why this paper is so important and how it's really moving the field forward for a clinically important problem. So thank you both so much for joining us here today on Circulation on the Run. Dr. Justin Grodin: Thank you. Dr. Pieter Martens: Thank you for having me. Dr. Mercedes Carnethon: I really want to thank our listeners for joining us today for this episode of Circulation on the Run. I hope you will join us again next week for more exciting discussions with our authors. 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

    Circulation January 10, 2023 Issue

    Play Episode Listen Later Jan 9, 2023 24:41

    Please join authors Loren Field and Sean Reuter, as well as Associate Editor Thomas Eschenhagen as they discuss the article "Cardiac Troponin I-Interacting Kinase Affects Cardiomyocyte S-Phase Activity But Not Cardiomyocyte Proliferation." Dr. Greg Hundley: Welcome listeners, to this January 10th issue of Circulation on the Run, and I am Dr. Greg Hundley, associate editor, director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Peder Myhre: I am Dr. Peder Myhre from Akershus University Hospital and University of Oslo in Norway. Dr. Greg Hundley: Well, listeners, this week's feature discussion delves into the world of preclinical science and evaluates cardiac troponin I and its impact on S phase activity in cardiomyocytes, and does that relate to cardiomyocyte proliferation. But before we get to that, how about we grab a cup of coffee and Peder and I will work through some of the other articles in the issue. Peder, how about this week I go first? Dr. Peder Myhre: Go ahead, Greg. Dr. Greg Hundley: Right. So Peder, this first study evaluated whether the burden of positive coronary artery calcification on cardiovascular disease differed by multidimensional individual characteristics, and so the investigators led by Dr. Kosuke Inoue from Kyoto University sought to investigate the heterogeneity in the association between positive coronary artery calcium and incident cardiovascular disease. And so Peder, to examine this question, the authors implemented a cohort study design that included adults aged greater than 45 years, free of cardiovascular disease, from the Multi-Ethnic Study of Atherosclerosis, or MESA, and after propensity score matching in a one-to-one ratio, they applied a machine learning causal forest model to, first, evaluate the heterogeneity in the association between positive coronary artery calcium and incident cardiovascular disease and then, second, to predict the increase in cardiovascular disease risk at 10 years when the coronary artery calcium score was greater than zero, so versus is it zero at all at the individual level? Dr. Peder Myhre: Oh, Greg, that is so cool, so using machine learning for coronary artery calcium and risk prediction, I'm very excited. What did they find? Dr. Greg Hundley: Right, Peder, so the expected increases in cardiovascular disease risk when the coronary artery calcium score was greater than zero were heterogeneous across individuals. Moreover, nearly 70% of people with low atherosclerotic cardiovascular disease risk showed a large increase in cardiovascular disease risk when the coronary calcium score was greater than zero, highlighting the need for coronary artery calcium screening among such low-risk individuals. And Peder, future studies are really needed to assess whether targeting individuals for coronary artery calcium measurements based on not only the absolute ASCVD risk, but also the expected increase in CVD risk when a CAC score is greater than zero and whether that improves overall assessment of cardiovascular outcomes. Dr. Peder Myhre: Wow, that is so clinically relevant and very interesting. And we're actually going to stay clinically relevant with the next paper which is about anti-platelet therapy after PCI. And this paper describes the long-term results of the HOST-EXAM trial. To remind you, Greg, the HOST-EXAM trial was an investigator-initiated prospective, randomized, open label, multicenter trial done at 37 sites in Korea. They enrolled patients who had undergone PCI with DES and maintained dual anti-platelet therapy without any clinical event for a mean 12 months and then they were randomized one to-one to either clopidogrel, 75 milligrams once daily, or aspirin, 100 milligram once daily. The primary results of this trial was published in Lancet in 2021 and showed superiority of clopidogrel over aspirin in prevention of the composite of MACE and major bleeding during 24 months of followup. And then, through the current paper, this describes the results of the post trial extended followup of about five years. Dr. Greg Hundley: Very nice, Peder, so aspirin versus clopidogrel and looking at the maintenance of that monotherapy and cardiovascular outcomes. Wow, so what did they find? Dr. Peder Myhre: Yeah, Greg. They, in this extended followup study, had a total of 5.8 years median followup, and the primary endpoint occurred in 12.8% in the clopidogrel group versus 16.9% in the aspirin group, and that has a range of 0.74 with a 95% conference interval ranging from 0.63 to 0.86. So also the clopidogrel group had lower risk of the secondary thrombotic endpoint and the secondary bleeding endpoint while there was no significant difference in the incident on all caused death. So Greg, to conclude, these very interesting results from the primary analysis of the HOST-EXAM trial was consistent through the longer followup, and this support the use of clopidogrel over aspirin monotherapy from 12 months onwards after PCI. Dr. Greg Hundley: Very nice Peder, beautiful description and sounds like long-term clopidogrel use over aspirin was quite beneficial. Well, the next study comes to us from the world of preclinical science, and it is from the investigative group led by Dr. Yunzeng Zou from Shanghai Institute of Cardiovascular Diseases and the Zhongshan Hospital and Fudan University. Peder, the study pertains to diabetes. So diabetic heart dysfunction is a common complication of diabetes mellitus and cell death is a core event that leads to diabetic heart dysfunction. However, the time sequence of cell death pathways and the precise intervening time of particular cell death type remained largely unknown in diabetic hearts. And so, Peder, this study aimed to identify the particular cell death type that is responsible for diabetic heart dysfunction and propose a promising therapeutic strategy by intervening in this cell death pathway. Dr. Peder Myhre: Wow, Greg, that is really interesting. Heart dysfunction in diabetes is something that we really have to learn more about and I'm so excited to hear what these authors found, Greg. Dr. Greg Hundley: Right. So first, Peder, the authors identified necroptosis as the predominant cell death type at later stages in the diabetic heart. And then second, Peder, the CB2 receptor, and we'll call that CB2-R, recruits transcription factor Bach2 to repress necroptosis and protects against diabetic heart injury while hyperglycemia and MLKL in turn phosphorylates CB2-R to promote ubiquitous dependent degradation of CB2-R, thus forming a CB2-R centric feedback loop of necroptosis. And finally, Peder, cardiac CB2-R or Bach2 expression negatively correlates with both MLKL 10 expression and the extent of diabetic heart injuries in humans. And so the clinical implications of these findings, Peder, are that the CB2-R centric necrotic loop represents a promising target for the clinical treatment of diabetic heart injuries. Dr. Peder Myhre: So Greg, this paper that comes to us from corresponding author Amanda Paluch from University of Massachusetts Amherst, is a meta-analysis of eight prospective studies with device measured steps including more than 20,000 adults who were followed for CVD events. And the mean age of participants in this study was 63 years and 52% were women. And the participants were followed for a median of 6.2 years and 1,523 cardiovascular events occurred. So first, Greg, there was a significant difference in the association of steps per day in cardiovascular disease between older, that is greater or equal to 60 years, and younger, that is less than 60 years adults. So for older adults that has the ratio for cardiovascular disease using Q1 as reference was 0.80 for Q2, 0.62 for Q3, and 0.51 for Q4. And for younger adults that has ratio for cardiovascular disease using Q1 as reference was 0.79 for Q2, 0.90 for Q3, and 0.95 for Q4. And in the paper, Greg, there are some beautiful, restricted cubic lines that really illustrate the association between daily steps and the risk of cardiovascular disease among older adults and in younger adults. So the authors conclude that for older adults taking more daily steps is associated with a progressively lower risk of cardiovascular disease. And monitoring and promoting steps per day is a simple metric for clinician patient communication and population health to reduce the risk of cardiovascular disease. Dr. Greg Hundley: Well, Peder, we've got some other very interesting articles in this issue and how about we dive into that mail bag and discuss a few of those. So I'll go first. The first is a Perspective piece by Professor Powell-Wiley entitled “Centering Patient Voices through Community Engagement in Cardiovascular Research.” A very important topic where can those in the community actually help us design meaningful outcomes for our research initiatives? And next Peder, there is a Research Letter from Professor Evans entitled “Increasing Mononuclear deployed Cardiomyocytes by Loss of E2F7/8, and does that fail to improve cardiac regeneration post myocardial infarction?” Dr. Peder Myhre: Thanks, Greg. We also have an ECG Challenge by Dr. Li entitled, “What Is The Truth Behind Abnormal ECG Changes?” And this is describing a very rare and interesting cause of ST segment elevation. I recommend everyone to read that case. We also have our own Nick Murphy who gives us the Highlights from the Circulation Family of Journals where he summarizes five papers from the Circulation subspecialty journals. First, the experience with a novel visually assisted ablation catheter is reported in circulation A and E. The impact of various exercise training approaches on skeletal muscle in heart failure with preserved the F is presented in circulation heart failure. Gaps in heart failure treatment over a decade are reported in circulation cardiovascular quality and outcomes, and the associations of machine learning approaches to plaque morphology from coronary CTA with ischemia are reported in circulation cardiovascular imaging. And finally, Greg, an observational study of left main PCI at sites with and without surgical backup is reported in circulation cardiovascular interventions. Let's go on to the feature paper today describing the cardiac troponin I interacting kinase and the impact on cardiomyocyte S phase activity. Dr. Greg Hundley: Great, let's go. Welcome listeners to this January 10th feature discussion. Very interesting today as we are going to delve into the world of preclinical science. And we have with us today Dr. Loren Field and Dr. Sean Reuter from University of Indiana in Indianapolis, Indiana. And our own associate editor, Dr. Thomas Eschenhagen from University Medical Center of Hamburg in Hamburg, Germany. Welcome gentlemen. Well, Loren, 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. Loren Field: Sure. This study actually came about in a rather roundabout fashion. We were doing a study with Kai Wollert in Hanover, Germany, where we were looking at the impact of a CXCR4 antagonist, which is used to mobilize stem cells from the bone marrow. And we had sent our mice over to Kai's lab and we have a mouse model that allows us to track S phase activity in cardiac myocytes, so these are cells are starting to replicate. And Kai crossed them into a different genetic background. And when he sent the mice back to us to analyze the hearts, we observed that we saw things that we never saw before in our experiments here. His injury model was different than ours and now the mouse also had a genetic background, so we had to spend about a year to figure out if it was the injury model or the background. It turned out to be the genetic background, and the phenotype was these mice had about a 15-fold elevated level of cell cycle reentry. So then it became a relatively simple genetics game where we took the progenitor mice, made F1 animals, looked for the phenotype, did backcross animals, and basically identified the gene responsible for the phenotype. Dr. Greg Hundley: Very nice. And so in this study moving forward, what hypothesis did you want to address? Dr. Loren Field: Well, the main hypothesis was to figure out what the gene was and then secondarily to figure out the degree of cell cycle progression. When the cell is proliferating, the first task is to replicate its genome, which is S phase activity that's followed by the nuclei dividing and then finally by the cell itself becoming two cells. So our task was to identify, first, the gene and secondly, how far through the cell cycles the cells progressed. Dr. Greg Hundley: Very nice. And how did you construct your experiment? Dr. Loren Field: It was, again, very straightforward. It was simply setting up the appropriate genetic crosses to produce the animals. For the past 10, 15 years, we've been developing a computer assisted assay that allows us to identify the anatomical position of S phase positive cardiac myocytes in sections of the heart. And basically, we apply that program to the different genetic backgrounds and after that it's a ball of mapping studies, QTL mapping. Dr. Greg Hundley: So really mechanistic understanding. Well listeners, we're next going to turn to Sean, and Sean, can you describe for us your study results? Dr. Sean Reuter: Yes, as Loren stated, we saw a 15-fold increase in the S phase activity within the remote zone. Now we partition the heart in three different zones after injury, so the scar, the border zone, and then the remote zone or injury. And as Loren stated, we saw a 15-fold increase in the S phase activity, cell cycle activity, in the remote zone. And it's only because we have this system in hand that we can anatomically map the S phase activity within the heart that we were able to detect and also quantify this. And I think that's the reason we discovered this particular phenotype. But in addition to that, we performed RNA-seq or Exome sequencing and discovered that TNNI3K was the responsible gene for elevated S phase activity within the remote zone and border zone, but interestingly not in the scar. Dr. Greg Hundley: Very interesting, Sean, and so describe for us the importance of the TNNI3K and its relationship to this S phase. Dr. Sean Reuter: Sure. This particular gene was first discovered around 2000, and it's been studied for a while now, but the targets of this kinase specifically expressed in the heart, and it does get elevated after injury, but the actual targets are not well described or well known. It's believed that it phosphorylates some mild filament fibers and structural proteins, but the actual mechanism and the consequence of this is not known. So when we saw this in the remote zone, the elevated S phase, our current theory is that we believe that it's probably increasing oxidative stress that would basically further out from the at-risk zone or the border zone and then it now is in the remote zone. So we think it's just causing the heart, a pathological area of the heart, basically to expand. And so that's our current theory. Other groups have published on the oxidative stress in over expression of TNNI3K as well. Dr. Greg Hundley: Very nice. Well listeners, next we are going to turn to our associate editor, Thomas many articles come your way and come across your desk. What attracted you to this particular article, and how do we put its results really in the context of cardiac regeneration? Dr. Thomas Eschenhagen: Indeed, there were several arguments. It's a cool paper and the whole field is still very important. As probably most of you know, the field have a rough ride over the last 20 years, went up and down, lots of bad findings. And in the end it turns out that we are there where we have been 20 years ago, the mammalian heart essentially doesn't regenerate. So anything which would improve that would be of very major importance. Why is it a good paper? Because it starts from a very clear finding, one mouse, which looks like strongly regenerating after MI, another mouse line, which doesn't. And so by applying, let's say, classical genetic, very stringent methodology, Loren Field and his group identified this troponin I kinase to be the culprit. And they also proved it, because putting it back in the strain with a low, so-called, regeneration brought it back to the other level. So it's a very clear, nice methodology. And finally, it's also a bit provocative because others in a very prominent paper, actually, have shown that this kinase... Or they concluded more or less just the opposite. The reason for the discrepancy is not quite clear and I was very happy to learn that the two groups actually discussed about it. So it's not just a bad controversy, but something which brings forward science. And finally, I think something we didn't talk about yet today, what I particularly liked, maybe the most, on this paper is that this group didn't stop at the point of DNA synthesis. Everybody else would've probably said, "Okay, here we are, one regenerate the other doesn't." But in the very important extra finding of this paper is that this is just increased DNA synthesis and not more myocytes. And this distinction is so critical to the field because people forget that adult mammalian cardiomyocytes often have several nuclei and individual nuclei have more than one set of chromosomes, so this polyploid. And so if you see DNA synthesis like in this paper, it doesn't necessarily mean more myocytes. And actually here it was shown that it is not more myocytes but more polyploidization and making this difference so clear, I think it's a very important contribution to the field. Dr. Greg Hundley: Very nice. Well, listeners, we're going to turn back to each of our guests today and we'll start with you Loren. Based on your results, what do you see as the next study moving forward in this sphere of research? Dr. Loren Field: I think these results made me appreciate for the first time that the intrinsic level of cell cycle reentry, that's just the S phase, not the cell division, is actually much higher than I had thought previously. And this was because we just fortuitously, or I guess anti-fortuitously, we're using a strain that had low levels of S phase induction. If you calculate the turnover, if every nucleus that it synthesized DNA actually went on to have that cell divide, you could replace a 50% loss of myocytes over the course of about 550 days, give or take. And to me, that's actually telling me that if we could push those cells from just being polypoid, as Thomas was saying, to actually go through cytokinesis, there would be enough intrinsic activity to go forward. So this really tells me that what we should be focusing on is now not trying to induce cell cycle, but to allow the cells that are entering the cell cycle to actually progress through it. Dr. Greg Hundley: Very nice. And Sean? Dr. Sean Reuter: Yes, well, echoing Loren's point there, it's really not necessarily cell cycle induction, it's cell cycle completion to the cytokinetic fate. And that's the key. If we can get to that point, if we can figure out the mechanism to get to that point, then we have a wonderful discovery. However, we're not quite there yet, but we hope to be. Dr. Greg Hundley: And Thomas. Dr. Thomas Eschenhagen: Well, nothing to add really from my side, except that I would like to know what this Troponin I kinase does, because that is somehow still a missing link. How does this kinase lead to more DNA synthesis or the initiation of cell cycling? That would be an important finding and I'm sure there will be more research going on. Particularly also, to solve this discrepancy, I mean, there must be something in it and we don't quite yet know how, but I think we are in a good way. I'm sure there will be papers showing that soon. So I think that's, again, a very good start for this discussion. Dr. Greg Hundley: Well, listeners, we want to thank Dr. Loren Field, Dr. Sean Reuter and Dr. Thomas Eschenhagen for bringing us this really informative study in mammalian myocellular regeneration, highlighting that the level of cardiomyocyte cell cycle reentry in hearts expressing TNNI3 kinase would lead to significant regenerative growth if each cardiomyocyte exhibiting S phase activity was able to progress through cytokinesis. And this in turn suggests that identification of factors which facilitate cardiomyocyte cell cycle progression beyond S phase will be key to unlocking the intrinsic regenerative capacity of the heart. 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

    Circulation January 3, 2023 Issue

    Play Episode Listen Later Jan 3, 2023 26:48

    This week, please join author Judith Hochman, Editorialist Steven Bradley, and Guest Host Mercedes Carnethon as they discuss the article " Survival After Invasive or Conservative Management of Stable Coronary Disease" and editorial “If the Fates Allow: The Zero-Sum Game of ISCHEMIA-EXTEND.” Dr. Greg Hundley: Welcome everyone to our new year 2023, and we are here on this January 3rd edition of Circulation on the Run. I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Peder Myhre: I am Dr. Peder Myhre, Social Media Editor and doctor at the Akershus University Hospital and University of Oslo. Dr. Greg Hundley: Very nice. Well, welcome listeners and this week's feature, ah, very interesting. You know many times patients with stable coronary artery disease, we're seeing a lot in the literature about an invasive strategy versus a conservative strategy. But what happens long term for these patients? What's their prognosis? Well, more to come in the feature discussion. But first, how about we grab a cup of coffee and we discuss some of the other issues in this session. Peder, would you like to go first? Dr. Peder Myhre: Yes, Greg I would love to and the first paper today is very interesting and relates to one of the most important challenges globally, namely climate changes and extreme temperatures. And in this paper, which comes to us from corresponding author, Barrak Alahmad from Harvard Chan School of Public Health in the United States, together with a large international group of authors, investigated the associations between extreme temperatures and cardiovascular cause-specific mortality in 567 cities in 27 countries from 1979 to 2019. Dr. Greg Hundley: Wow Peder, that is a really large comprehensive study. So, how did they perform this analysis? What did they find? Dr. Peder Myhre: So Greg, the investigators collected city-specific daily ambient temperatures from weather stations and analyzed cause-specific cardiovascular mortality and excess deaths in association with extreme hot and extreme cold temperatures. And in total, the analysis included more than 32 million deaths from any cardiovascular cause, which were subdivided into deaths from ischemic heart disease, stroke, heart failure and arrhythmia and at extreme temperature percentiles. And that is defined as heat above the 99th percentile and as cold below the first percentile were associated with a high risk of dying from any cardiovascular cause, ischemic heart disease, stroke and heart failure as compared to the minimum mortality temperature, which is the temperature associated with least mortality. And Greg, across a range of extreme temperatures, hot days above the 97.5 percentile and cold days below the 2.5 percentile accounted for more than two and more than nine excess deaths for every thousand cardiovascular death respectively. And heart failure was associated with the highest excess death proportions from extreme hot and cold days. So Greg, it seems like extreme temperatures really impact the cardiovascular mortality across the globe. Dr. Greg Hundley: Yeah, beautiful description Peder. And I think what was really exciting about that particular article is you had results from 27 countries. Wow, so really quite a global study and very informative. Dr. Peder Myhre: Yes, indeed very impressive. Dr. Greg Hundley: Well, Peder my next study comes to us from the world of preclinical science. And Peder, these investigators led by Professor Jose Luis de la Pompa from CNIC, evaluated two structural cardiac diseases, left ventricular non-compaction and bicuspid aortic valve. And they wanted to determine if those two conditions were caused by a set of inherited heterozygous gene mutations affecting the notch ligand regulator, Mind bomb-1 and co-segregating genes. Dr. Peder Myhre: Okay Greg, so we are looking at mechanisms for non-compaction and bicuspid aortic valve. What did they find? Dr. Greg Hundley: Right Peder, so whole exome sequencing of the left ventricular non-compaction families identified heterozygous missense mutations in five genes co-segregating with E3 ubiquitin protein ligase-1 Mib-1 as well as left ventricular non-compaction. And corresponding mouse models showed that left ventricular non-compaction or bicuspid aortic valve in a notch-sensitized genetic background. Now, also gene profiling showed that increased cardiomyocyte proliferation and defective morphological and metabolic maturation in mouse hearts and human pluripotent stem cell cardiomyopathy. Biochemistry suggested a direct interaction between notch and some of the identified gene products. And so, these data Peder support a shared genetic basis for left ventricular non-compaction and bicuspid aortic valve with Mib-1 notch playing a crucial role. And thus, identification of heterozygous mutations leading to left ventricular non-compaction or bicuspid aortic valve may allow us to expand the genetic testing panel repertoire for better diagnosis and or risk stratification of both of these conditions, left ventricular non-compaction and bicuspid aortic valve. Dr. Peder Myhre: All right, that is really great and novel linking left ventricular non-compaction to bicuspid aortic valve, really great. And now Greg, we're going to go back to clinical science and we're going to talk about lipoprotein(a) or Lp(a). And as you know, elevated Lp(a) is a common risk factor for cardiovascular disease outcomes with unknown mechanisms. And the authors of this next paper coming to us from corresponding author Olli Raitakari from University of Turku in Finland, examined Lp(a)'s potential role in identifying youths who are at increased risk of developing adult atherosclerotic cardiovascular disease, ASCVD. And they did this by measuring Lp(a) in youths nine to 24 years old and linking that to a diagnosis of ASCVD as adults and also linking it to carotid intermediate thickness in the Young Finns Study. And in addition, these results were validated in the Bogalusa Heart Study. Dr. Greg Hundley: Oh, very nice Peder. So, what did they find? Dr. Peder Myhre: So Greg, those who have been exposed to high Lp(a) levels in youth and that was defined as greater than or equal to 30 milligrams per deciliter, had about two times greater risk of developing adult ASCVD compared to non-exposed individuals. In fact, all the following youth risk factors were independently associated with a higher risk. Lp(a), LD, cholesterol, body mass index and smoking all independently associated with ASCVD. And similar findings were made in the validation cohort who were participants with a high Lp(a) had 2.5 times greater risk of developing adult ASCVD compared to non-exposed individuals. And this also persisted in adjusted models. Now, what about the carotid intermediate thickness? In that analysis, there were no associations detected to youth Lp(a) levels in either of the cohorts. Dr. Greg Hundley: Very nice, Peder. So, great description of the utility of lipoprotein(a) measurements in the youth and for predicting future major cardiovascular events. Well, the next paper goes back to the world of preclinical science. And Peder, cardiac hypertrophy increases demands on protein folding, which causes an accumulation of misfolded proteins in the endoplasmic reticulum. Now, these misfolded proteins can be removed via the adaptive retro-translocation, poly-ubiquitylation and a proteasome mediated degradation process. The endoplasmic reticulum-associated degradation, ERAD, which altogether as a biological process and rate has not been studied in vivo. So, these investigators led by Dr. Christopher Glembotski from University of Arizona College of Medicine, investigated the role of ERAD in a pathophysiological model and they examined the function of the functional initiator of ERAD, VCP-interacting membrane protein and positing that the VCP-interacting membrane protein would be adaptive in pathological cardiac hypertrophy in mice. Dr. Peder Myhre: Thanks Greg. So, we're talking about degradation of the endoplasmatic reticulum and the association to hypertrophy. So, what did these investigators find, Greg? Dr. Greg Hundley: Right, Peder. So, this was really the first study to demonstrate that endoplasmic reticulum-associated protein degradation or ERAD is responsible for degrading and thus, regulating the levels of a cytosolic non-endoplasmic reticular protein. The results reported here describe a new mechanism mediating the pathological growth of the heart, such that in the healthy heart SGK-1 levels are low due to ERAD-mediated degradation. While in the setting of pathology, ERAD-mediated degradation of SGK-1 is disrupted, allowing the pro-growth kinase to accumulate and contribute to pathological cardiac hypertrophy. And so Peder, the clinical relevance of these findings is that the investigators found that a variety of proteins that constitute the ERAD machinery were decreased in both mouse and human heart failure samples while SGK-1 was increased, supporting the possibility that SGK-1 is a contributor to the disease phenotype. And this is notable and that these studies could lead to the development of new therapeutic approaches for managing pathological cardiac hypertrophy and heart failure that target the ERAD to restore efficient SGK-1 degradation. Dr. Peder Myhre: That was an excellent explanation of a very difficult topic. Thank you, Greg. Dr. Greg Hundley: Well, Peder how about we take a look and see what else is in the issue? And now I'll go first. Well, first there's an In Depth by Professor Ntsekhe entitled, "Cardiovascular Disease Among Persons Living with HIV: New Insights into Pathogenesis and Clinical Manifestations within the Global Context." And then, there's a Research Letter by Professor Verma entitled, "Empagliflozin in Black Patients Versus White Patients With Heart Failure: Analysis of EMPEROR results-Pooled." Dr. Peder Myhre: Great Greg and there is an On My Mind by Gabriel Steg entitled, "Do We Need Ischemia Testing to Monitor Asymptomatic Patients With Chronic Coronary Syndromes?" Very timely and interesting. And finally, there is an AHA Update from Michelle Albert, the President of the AHA entitled, "Tackling Adversity and Cardiovascular Health: It is About Time." Dr. Greg Hundley: All right. Well Peder, how about we get onto that feature discussion looking at survival after invasive or conservative management in stable coronary heart disease? Dr. Mercedes Carnethon: Thank you so much for joining us for this episode of Circulation on the Run. I'm Mercedes Carnethon, Professor and Vice Chair of Preventive Medicine at the Northwestern University, Feinberg School of Medicine. And I'm very excited today to have as a guest, Dr. Judith Hochman, who is going to be discussing the long-awaited findings from the ISCHEMIA-EXTEND trial that are looking at survival after invasive or conservative management of stable coronary disease. Really pleased to have you with us today, Judy to hear about these findings. Dr. Judith Hochman: It's a pleasure to be here. Dr. Mercedes Carnethon: Thank you. So, just to start off, can you tell us about this study? What motivated this long-term follow-up of this particular trial? Dr. Judith Hochman: Yeah, so as I think the viewers or the listeners will recall, we built on a wealth of data from COURAGE and BARI 2D, some of the landmark trials that looked at revascularization versus optimal medical therapy or guideline-directed medical therapy alone. We tested an invasive strategy versus a conservative strategy dating back already to 2012 is when we started. And we had a five component primary outcome, which included cardiovascular death, myocardial infarction or hospitalization for unstable angina, heart failure or resuscitated cardiac arrest. And at the end of 3.2 median years of follow-up, we saw no difference in the primary outcome in that the curves crossed with some excess risk upfront due to periprocedural MI and decreased risk of spontaneous MI long-term. But the net overall timeframe spent free of event was similar between the groups. So, we did observe improved quality of life for the invasive strategy, but in terms of clinical outcomes there was no difference. So, cardiovascular death at the end of that time period was no different between the groups, all-cause mortality was no different, non-cardiovascular death, there was actually an increase in the invasive group, which was somewhat of a mystery. We can get into that a little bit later because I think that becomes important. But 3.2 years meeting and follow-up is relatively short. So, everyone was very interested in what would the long-term outcomes be. So, we had another grant from the National Heart, Lung and Blood Institute to follow these patients long-term. And this is an interim report with seven years of follow-up, a median of 5.7 years. And the bottom line is that all-cause mortality was the same at seven years but for the first time, an invasive strategy resulted in lower cardiovascular mortality, which was very interesting and very exciting except that it was offset, exactly offset by the continued excess that we had previously observed in non-cardiovascular mortality. And that's basically the upshot of what we just reported and why we continue to follow patients and why we're going to continue to follow patients and have a final report in 2026. Dr. Mercedes Carnethon: This is really fantastic work. As you point out, the initial follow-up was fairly short and the findings were so critically important demonstrating that there were subtle differences between the two approaches but that overall, things appeared relatively similar. Did it surprise you? Oh, please correct me. Dr. Judith Hochman: I should point out that because there were less spontaneous MIs during follow-up and spontaneous MIs are associated with a heightened risk of subsequent death more so than the periprocedural MIs, we did hypothesize and we're very interested in longer term cardiovascular and all-cause mortality thinking that those reduced spontaneous MIs in the invasive group would be associated with reduced cardiovascular death and perhaps reduced mortality. As I did indicate, cardiovascular death mortality was reduced but all-cause mortality was the same with a hazard ratio of 1.0. Dr. Mercedes Carnethon: Well, nothing seems more clear than a hazard ratio of 1.0 with those very tight confidence limits so thank you so much. I'm really pleased that our editorialist, Dr. Steve Bradley was also able to join us today because to hear his thoughts about where this fits in the context of what we know can be really insightful. So, I'd really love to turn to you, Dr. Bradley. In your opinion, why was this study question so important and tell us a little bit about how you think the clinical field should use these findings. Dr. Steven Bradley: Absolutely and thanks for having me. I think there were some indication that perhaps the farther we follow the patients out from the original ISCHEMIA trial that we might start to see some evidence of benefit for revascularization. I think Dr. Hochman spoke about the evidence of more of these spontaneous myocardial infarctions that were happening in the non-revascularization arm of the study and an association with worse cardiovascular outcomes in patients that experience spontaneous events. And so, the thoughts might be that over time we would see the benefit of that. And certainly if you parse out cardiovascular versus non- cardiovascular outcomes, we do, we see lower rates of cardiovascular death in the patients who undergo revascularization but it's balanced out by non-cardiovascular death. And so, it becomes a zero sum game for a patient. They want to be alive, it doesn't matter by what mechanism. So, if we have a therapy that doesn't actually prolong their life but it leads to different mechanisms by which they have an outcome, that's important for us to understand. This adds to an already robust evidence-based that ISCHEMIA really did inform and it gives us that long-term trajectory to help us understand for patients what the implications are. I will note that and we've commented in the editorial and this is something that was shown in the original ISCHEMIA trial, that it's not just about mortality for patients, it's important that we help them live better as well. And certainly we know that revascularization is associated with quality of life improvement so that's an important part of the conversation with patients. But again, continuing to refine our understanding of what the implications of revascularization are for mortality is where this study leads us now. Dr. Mercedes Carnethon: Thank you so much. One of the things that I find so impressive about clinical trials of this scale are that you incorporate such a broad audience. I note that 36 countries contributed data to this particular trial. I wonder whether, did you have an opportunity to investigate whether these findings were similar in low and middle income countries as compared with higher income countries? And how would you expect clinicians in low and middle income countries to use this information? Dr. Judith Hochman: That's a great question and yes, the treatment effect was similar across regions, didn't really have any very low income regions but we did have India was in the study and a number of South American countries. And I think it's incredibly important for those countries where there are very limited resources to reassure them, the practitioners and their patients that just because they can't afford an expensive invasive procedure, stenting or bypass, does not mean it's going to cut their life shorter, it's not going to make them survive for a shorter amount of time. Therefore, they can limit the use of scarce resources to the most severely impaired in terms of quality of life, the patients with the most frequent angina. It also became extremely relevant during COVID. Dr. Mercedes Carnethon: Tell me more. Dr. Judith Hochman: Well, elective procedures were shut down during COVID and more publications that cited the ISCHEMIA trial to say that they felt comfortable not being able to do elective stenting in patients with stable ischemic heart disease that would've met the ISCHEMIA trial criteria, which by the way we should add was preserved ejection fraction, we excluded ejection fraction less than 35, patients had to be stable. They could not have had two coronary syndrome within the last few months. They could not have had angina refractory to medical therapy and they could not have had left main disease. So, those are key. There are other exclusion criteria but those are the key exclusion criteria. Dr. Mercedes Carnethon: Thank you for that. And I can really see a corollary and I appreciate the messaging around similar outcomes and preserving resources. And I think certainly even within our own country where we see vast differences in access to intensive medical therapies or tertiary care medical centers who do these procedures on a higher volume, at least we can feel reassured that outcomes may be quite similar as far as mortality. What do you- Dr. Judith Hochman: If they take their guideline-directed medical therapy. Dr. Mercedes Carnethon: Thank you for pointing that out. Dr. Judith Hochman: It's incredibly important. John Curtis' group looked at adherent patients by the modified Morisky score versus non-adherent patients. Non-adherent patients don't have as good a health status as adherent patients. So, just that also adds to a wealth of literature that you have much better outcomes if you actually take your medications. Dr. Mercedes Carnethon: No, I think that's a very good point. What are your thoughts, Steve on what the next steps might be? Dr. Steven Bradley: Well, I know that as was pointed out earlier, there's going to be the opportunity to see additional longer term follow-up beyond this interim analysis. So, it'll be interesting to see what that continues to show us in terms of understanding applications on mortality. I'll pose a question that we posed within our editorial around trying to identify non-fatal outcomes to see if there are any opportunity to capture those non-fatal outcomes to give us an understanding of potential mechanisms for why there is this cardiovascular versus non- cardiovascular mortality difference by treatment arm? Certainly, that may be helpful. Dr. Judith Hochman: Sorry. We're very, very interested in the excess in non-cardiovascular death. So, we are as a result of this interim analysis, revising our case report form, which was very lean, pragmatic because the funding is relatively limited to include especially collection of data around malignancy. Because as we reported before, the non-cardiovascular deaths were largely malignancy and to some extent infection. And what was driving the difference, the excess in non-cardiovascular death as we published in American Heart Journal in the invasive group was excess malignancy. Dr. Mercedes Carnethon: That's really interesting. Dr. Judith Hochman: To our deep surprise and shock, it appeared that the only variable associated with that excess risk was the number of tests or procedures you had that involve radiation. And of course, we're talking about medical doses of radiation. And this short timeframe, three and a half to seven years, which is when the curve started to diverge to three and a half, we filed to seven years is not thought to ... it's thought to be too short a timeframe for exposure to radiation to lead to excess malignancy. So, we have partnered with some radiation experts, we are adding much more details to our case report form, not only in terms of death from malignancy but just the occurrence of malignancy. Did you get malignancy during the course of follow-up? And that's really critically important. We are not adding information about additional myocardial infarctions. We think that the key, if we're going to focus on site burden and how much they can actually collect, is to look at the mechanisms of death and the occurrence of malignancy, whether that leads to death or not, those are our top priorities at this point. Dr. Mercedes Carnethon: I could go on and on, I'm learning so much speaking with the two of you. And again, that really is the primary goal of our podcast to really have an opportunity to extend beyond what's written in the paper and really hear directly from the authors who led the study to hear your thoughts as well as those of the editorialists on where this is going. I really want to thank you both for the time you've spent today to share with our audience of the Circulation on the Run podcast. Dr. Judith Hochman: You're very welcome. Dr. Steven Bradley: My pleasure. Dr. Mercedes Carnethon: I just want to thank all of our listeners for joining us on this really stimulating discussion today on this episode of Circulation on the Run. Please tune in next week where we will have more exciting discussions like this one. Thank you. 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

    Circulation December 27, 2022 Special

    Play Episode Listen Later Dec 26, 2022 31:18

    In this week's Circulation on the Run podcast, we turn the show over to Circulation's Social Media Editors Dr. Pishoy Gouda and Dr. Peder Myhre. They interview the 2022 recipients of the Joseph Loscalzo Award for Best Basic Science Article, and the 2022 recipients of the James T. Willerson Award for Best Clinical Article. Dr. Maryjane Farr: Welcome everybody to Circulation on the Run. My name is Maryjane Farr, and I'm the digital strategies editor at Circulation. Carolyn and Greg are on break this week. And as part of the Circulation tradition, we turn the stage over to two of our social media editors, Dr. Peder Myhre from Oslo and Dr. Pishoy Gouda from Edmonton. They're going to be interviewing the 2022 winners of the Loscalzo Award and the Willerson Award. Take it away, Peter and Pishoy. Dr. Peder Myhre: Today. Pishoy, we have a very exciting issue of Circulation on the Run. We are going- Dr. Pishoy Gouda: We certainly do. Dr. Peder Myhre: Yeah. We're going to discuss two amazing papers that are award-winning and we're going to talk to the first authors who really know these papers and conducted the amazing work that we're going to display here today. Dr. Pishoy Gouda: Yeah, I'm excited. Peter. And with us today, we'll start talking about the recipients of the Loscalzo Award. So I wanted to start off by introducing Dr. Leo and Dr. Suvorava, who are the very proud recipients of the Loscalzo Award for their paper entitled Red Blood Cell and Endothelial eNOS Independently Regulate Circulating Nitric Oxide Metabolites and Blood Pressure. So welcome Doctors Leo and Suvorava. How are you guys doing today? Dr. Francesca Leo: Hi, thank you for the introduction and pretty well, I'm currently in Italy for my winter Christmas holidays, but I'm really excited and happy to be here today with you. Dr. Pishoy Gouda: Excellent. Dr. Suvorava: Hello. I'm also very happy to be here today. Thank you for your invitation and for your congratulations. It's a privilege and honor for me to be a recipient of this Dr. Loscalzo Award. Thank you. Dr. Pishoy Gouda: Well, I just wanted to start off by taking another second here to congratulate you both on this award. We all know the sheer amount of work and dedications to get these projects going, so congratulations. And I'm going to start off with a really easy question for you guys. When you found out that you were a recipient of the Loscalzo Award, who is the first person that you told? Dr. Francesca Leo: As I mentioned, I'm Italian and as a good Italian I need to say that. Of course, the first people I told were my parents because we all know that Italian and parents are just one thing. So they were the first ones. And then all of course, my partner and friends came second, parents first, family first. Dr. Pishoy Gouda: Very good. What about yourself, Tatsiana? Dr. Tatsiana Suvorava: Hi. Yeah. I had to think back like seven years ago and I very good remember one day when I was really excited about the results, what we found, I was in the lab, I was developing a western blood to check the functional ability of our models and it showed that it was very successful that we couldn't knock out our protein of interest almost completely. And at that day exactly, we had a lab meeting. So I directly pulled this image on my USB stick and then showed it on the lab meeting. So actually these were my colleagues who first hear about this. Dr. Pishoy Gouda: That's awesome. That's lovely. Well, after I got married, sometimes my parents get bumped to the second phone call and they weren't very happy about that and they let me know very clearly. But let's switch gears a little bit and tell us a little bit about how you made the decision to pursue academics. It's such a daunting career and a daunting topic sometimes. And how did you get interested in research and how did you find yourself coming into this research project? Dr. Francesca Leo: If I can start first. Well, I decided to pursue an academical career at the beginning following my master thesis that I did at the University of Pisa here. And I've always wanted to go abroad and gain experience, get to know different realities apart from Italy. And I was actually really lucky that I got the opportunity to work in the laboratory Professor Cortese-Krott because that gave me the opportunity to grow a lot, both personally and professionally, of course. I learned new techniques and together with our great team, we managed to achieve many goals. In particular, this paper, I must say that was my last satisfaction before my doctoral exam. So I think the feeling that you get after any also small achievement is something that you can really, I cannot find it hard to explain to people that are not in research or not in science in general. Dr. Pishoy Gouda: No, I totally agree. When I get a new data set, I get so excited and my wife is telling me, what are you doing is I just got new data and I'm like a little child on Christmas day. She doesn't understand it, but she appreciates that some people like that. What about yourself? What about yourself? Dr. Tatsiana Suvorava: Yeah, well my decision to pursue academic career started with as probably for many researchers, started from intense fascination from one discovery. I was at the beginning of my bachelors' science studies and then the Nobel Prize was given for the discovery of nitric oxide as a signaling molecule in a cardiovascular system. And I was so fascinated that the gaseous molecule so simple has so lots of responsibility in the body. And since that time, that was always in the focus of my research and this is for me, a lifelong journey. I'm still on the way. Dr. Pishoy Gouda: That's amazing, Tatsiana. And that sort of sets us up nicely. And as you guys know, I'm a interventional cardiologist. Basic science is a little bit farther from my memory. So I'll start off by admitting that my basic science research is not where it should be. But with that in mind, I was wondering if you could just tell our listeners a little bit about your research and why this question is so important and explain it to you like you were lowly clinicians that don't really understand basic science. Dr. Francesca Leo: I always take over Tanya, but yes, I have less to say than you. I must admit. Dr. Tatsiana Suvorava: Okay so let's start. No problem. Dr. Pishoy Gouda: It's a team effort. It's a team effort. Dr. Tatsiana Suvorava: Its a team effort and yeah. Ok. Dr. Francesca Leo: It's been a really teamwork, I must say from the really, really, really beginning. So this paper was, as I said, the central focus of my doctoral thesis. I just take two small part of it, of course, in particular, what is really important on the paper, I think that is we use really new mice models that Tanya and my Professor Cortese-Krott really and highly characterized at the really beginning, so developed completely from new, and they are mice that are expressing or not eNOS this protein that is responsible for nitric oxide production in the endothelium or in red blood cells. So the importance of this research was to demonstrate the role or pivotal role of eNOS expressed in the red blood cells in the modulation of blood pressure as well as circulating nitric oxide metabolites. And we actually did it with this paper. And considering that cardiovascular disease are one of the major causes of death nowadays, this results can really have important clinical and therapeutical implications for future research and real life, let's say. Dr. Tatsiana Suvorava: Yeah, maybe I could add to Francesca. Dr. Francesca Leo: Sure, Dr. Tatsiana Suvorava: Yeah. Dr. Pishoy Gouda: Of course. Dr. Tatsiana Suvorava: I think our research was especially important because it's identified the existence of previously unrecognized and actually non-canonical pathway, how the red blood cells can regulate blood pressure. And it was so exciting about this. Dr. Pishoy Gouda: Right. So trying to find out if the red blood cell, nitric oxide synthase can actually regulate blood pressure. And this has obviously lots of clinical implications. So in practice, how did you guys set up your experiments? How did you try to test the significance of the Enos red blood cells effects? Dr. Francesca Leo: Just if I can add something, what was really important. So what is known is that Enos expressing the endothelium plays an important role in the modulation of blood pressure. What we actually found out is that the one in the red blood cells also is involved and played a role that seems to be independent from the one played from the eNOS expressed in the endothelium. For answering your question, I also, I need to say I'm not the right candidate because this is a huge project that started about 10 years ago. So I was really, I repeated and I will always repeat it, I was really lucky to take part to this project and to get the opportunity to take part to this journey because it was really a journey and it gave me the opportunity to work with very different people and get in touch with very different realities, academical realities. And I can say that this project started from my previous boss and Tanya that they had this idea and started this whole project together with, of course Tanya is the one that is involved since the really beginning. So she can definitely better answer to this question. Dr. Tatsiana Suvorava: Yeah, thank you, Francesca. It's a long way actually what we did, and actually I started this particular project on the level of postdoc and eNOS and hypertension have been already in a center of my research interest for several years. And in a previous project what I had, I also had a transgenic mice, which were generated by conventional genetic approach by micro injection of D N a. And at that time we observed a significant contribution of external endothelial component into the blood pressure regulated. However, at that time we were not able to identify the exact extracellular allocation of this component. There were several candidates which were suggested, and one of them there were red blood cells. And everyone was kind of skeptical about this because the level of eNOS protein in red blood cells is extremely low. And furthermore, there were a lot of doubts how eNOS activity can be exported from the red blood cells because it's red blood cells are full of heme, which is a scavenger of nitric oxide. Furthermore, actually it was not clear how they transported and how it is released this activity. But now if we think that red blood cells are the largest component contributor to overall cell number in the body, so maybe then we can more critically think and then think that the total amount of red blood cells maybe compensate for this very low eNOS protein expression. And actually because they have a high density and their shape is erase high, so they provide a very sufficient release of this inactivity from red blood cells. But this idea was doubted for many years, although there it was reported that eNOS is expressed in red blood cells in 2006 was a paper. Dr. Pishoy Gouda: Well that's very exciting. So what we really learned is that eNOS system in both red blood cells and endothelial cells contribute to blood pressure regulation. Now I might direct this to you, Francesca. Well what does that mean for the clinicians in our audience? Well, what does that mean for a hypertension patients? Dr. Francesca Leo: So for clinicians, so, I must say these findings may have really important pathophysiological implication in the understanding of the interrelationships between hematologic and cardiovascular disease and may reveal the really novel therapeutic approaches to improve tissue perfusion. Moreover, our data and models may also help in understanding how red blood cells eNOS signaling can really affect red blood cells function, the scavenging of nitric oxide, as Tanya had previously said, as well as the crosstalk between nitric oxide and the sulfides that are of highly present in the bloodstream and in the body as well as oxygen transport. And may also enable us to refine the criteria for blood banking transfusion and to also try to develop new strategies or therapies for many diseases and pathologies where red blood cells are involved. For example, coronary artery disease, chronic kidney disease that normally are pathologists that show a decrease in the expression of eNOS expressed in the red blood cells or hematologic disease hemoglobinopathies, which are normally characterized by a systemic decrease in nitric oxide bioavailability or one of the most common diseases, sickle cell disease. Cause of course the shape of red blood cells is definitely also responsible of their functioning. And it can also determine, of course, an impairment or more alteration in the release of nitric oxide in the body. Dr. Tatsiana Suvorava: Yeah, maybe I'll just add few words. So actually that's open as a perspective that impairment of red blood cells, eNOS may contribute to the pathogenesis of hypertension. So this is the most important thing I think here in clinician point of view. Dr. Pishoy Gouda: Yeah, absolutely. Lots of different ways that this research might be heading. And like you were saying earlier, Tatiana research is really a longitudinal process. You started this almost a decade ago and I'm sure that there's more projects and plans that you have with this for the future. What are you working on now? Dr. Tatsiana Suvorava: Well, I'm still in academia and I'm still doing academic career, actually. We continued our study and we also studied pathophysiological significance of red blood cells eNOS for cardio protection. For example, in regulation of coronary blood flow, myocardial performance in myocardial infarction, acute myocardial infarction in vivo. We recently published this and here we could also see involvement of red blood cells eNOS, which limit infarct size in acute myocardial infarction. In a pipeline is also a manuscript about red blood cells and endothelial cells eNOS in exercise induced cardio protection and of course the other focus would be the role of red blood cells eNOS in other disease conditions and a chronicle kidney disease for example. It will be also investigated. So we are full of plans, however, I changed department, but I'm still having eNOS in focus and hypertension as well. Dr. Pishoy Gouda: Well that's really exciting stuff and yes, I just wanted to congratulate you both again Dr. Leo and Suvorava and thank you for taking the time to share with us your very clear passion for this topic and I wish you guys both the best of luck. Congratulations again. Dr. Francesca Leo: Thank you so much. Dr. Tatsiana Suvorava: Thank you so much. Dr. Pishoy Gouda: Well congratulations again to our award recipients and Peter, why don't you tell us a little bit about what article we're going to be talking about next? Dr. Peder Myhre: Yes, thank you so much Pishoy. And first, I must say it was so much fun to listen to you guys discuss the paper. You can really feel the passion for the science coming through the microphone. And that was for me as a clinician as well. I learned a lot. And now we're going to actually take a step and move over back to clinical science and we are going to talk to the winners of the James T. Willerson Award. So welcome doctors, Jeanne du Fey and Dr. Alexandra Prepoudis. Dr. Jeanna du Fay de Lavallaz: Thank you very much for having us on the podcast. It's a pleasure to be here and we're also very happy to be able to discuss this paper with you. And of course we were extremely glad to receive this award, so we're excited about the discussion. Dr. Peder Myhre: And so for the listeners who are not familiar with the Willerson Award, this award recognizes the best clinical paper published in circulation in the preceding 12 months. And this award honors Dr. Willerson, who was a major leader within American Heart Association. And among his roles, he served for over a decade as the editor-in-chief of circulation. And during his tenure, the journal transitioned away from a once monthly format, vastly expanded its international footprints and rose substantially in stature and impact. And speaking of international footprint, today we have authors from all over the world and I know both of you, Jeanne and Alexandra are from the amazing biomarker group in Basel led by Christian Mueller. So Alexandra, if we can start with you, I just want to learn a little bit more about you. Where do you work, where are you in your career and your areas of interest? Dr. Alexandra Prepoudis: Good evening and thank you for the introduction. My name is Alexandra Prepoudis and I'm currently a cardiology fellow at the University Hospital of Basel in Switzerland. I have always been very interested in clinical research, so I decided to join the group of Professor Christian Mueller in Basel for a year prior my residency in internal medicine. And that's how I met Jeanne and the whole study team. Dr. Peder Myhre: Very nice. And Jeanne, what about you? Dr. Jeanna du Fay de Lavallaz: So my name is Jeanne du Fey and I'm currently also a cardiology fellow at the hospital in Zurich. I moved a little bit, but my main research is still based in Basel. You don't leave Professor Mueller's group once you're in it. So I sticked around. So I am undertook physician scientist track after med school and for my MD PhD I was very lucky to integrate Dr. Mueller's group into the paper we are going to discuss tonight is actually the very first study that I designed during my PhD of course with a lot of help from the whole group of Professor Mueller, professor Mueller himself and of course Alexandra who joined a little bit later and really helped us tackle quite a big piece of the biomarker research that I'm very excited to talk about. Dr. Peder Myhre: So that is amazing. So this is the first paper you designed and what a wonderful debut because today we're going to discuss this award-winning paper and it is entitled Skeletal Muscle Disorder and Non-Cardiac Source of Cardiac Troponin T. And of course we are within the field of troponin and I must admit Jeanne and Alexandra that I myself is a troponin nerd myself. I love research and learning more about troponin and for me this paper was really something I was eager to learn more about because we've all been questioning what is the impact of skeletal muscle disease on troponin. So perhaps Jeanne, if you could start to explain the background for this study, and what was the research question? Dr. Jeanna du Fay de Lavallaz: So in the past years, I think there were quite a few reports. These were mostly case series of what you have just mentioned. So it's this observation that skeletal muscle disease might actually have an impact on some troponin measurements and we were not exactly sure which. So there are these two main isophones of troponin, the troponin T and the troponin I. Depending on the hospital, depending on the country, one of both might be measured either the troponin I or the troponin T. And then for troponin T we have only one essay and then for troponin I there are several of them. So there is kind of a big mix up there of what is possibly obtainable to assess cardiovascular health and basically also more coronary health, well cardiovascular health in patients that we see every day in the clinic. And well, as you just mentioned, we had noticed in the past that sometimes it's troponin T was behaving in weird way in patients that were also suffering of some muscle skeletal muscle disease. So Prof. Mueller is leading a very large group biomarkers on troponin research and this is something that we decide to tackle in a very structured way in order to be able to rehab an answer and bring something to the field that might be maybe a little bit more consistent than this, however very interesting case series, but that were maybe a little bit done on very specific disease and a little bit all over the place. Dr. Peder Myhre: Exactly, and this is exactly what really made this paper so amazing is that first of all, you structured the clinical part of it with a prospective cohort. You did multiple essays on the patients and you even included some translational work on top of that, which is truly amazing. So I was wondering, Alexandra, if you perhaps could start with explaining the clinical part of the study, the patient cohort, the mythology use, et cetera. So please, Alexandra. Dr. Alexandra Prepoudis: We enrolled patients with muscle complaints. So for example, muscle pain, weakness, stiffness or fasciculations. And we enrolled them at four sites in two countries, most of them during ambulatory visits. And from each patient we collected a blood sample and we measured four different high sensitivity cardiac troponin assays. So one for troponin T and three for troponin I. Then patients underwent the cardiac workup including E C T, echo cardiography and cardiac M R I depending on the clinical indication. As a control group, we used patients from a prior study where patients who presented to the emergency department with the leading symptom of chest pain were enrolled. So of these we analyzed patients without skeletal muscle disease in whom a cardiac cause of chest pain could be excluded. Dr. Peder Myhre: Great. So really a big and well pheno typed group of patients. And before we go to the results, we're going to also learn a little bit about the experimental part of the study that you conducted. So Jeanne, if you would just explain what was, this was something with the gene expression in the muscles, right. Dr. Jeanna du Fay de Lavallaz: So we decided to be a little bit original and to bring it back to the bench instead of bringing it to the bedside as we usually do. And- Dr. Peder Myhre: I love it. Dr. Jeanna du Fay de Lavallaz: We will soon. We were also very lucky to have amazing collaborators because that allowed us to collaborate with a rheumatologist with neurologists. And these doctors might have in the past collected some muscle tissue for completely different muscle analysis. So in order to phenotype the diseases that the patients were actually suffering of and we're also lucky enough so that there was sometimes some of this muscle tissue is still available and we basically extracted mRNA from these skeletal muscle samples. And what we looked at was the mRNA of the different troponin genes that we could find in there. So as you probably know, there is some genes coding for skeletal troponin and there are some genes coding for cardiac troponin. And what we could see that was, we might come to that in the results, but basically our goal was to look at the expression of the different skeletal or cardiac troponin in these skeletal muscle samples. Dr. Peder Myhre: Exactly. And the next question is going to be difficult because I want you to summarize the findings and there are so many findings to supplement. This is really, it's like pressure. But please Alexandra, can you try to summarize the primary results of this paper? Dr. Alexandra Prepoudis: Yes, of course. I will try my best. So maybe first about half of the cohort showed the cardiac disease IE the coronary heart disease, atrial fibrillation, or chronic heart failure. So cardiomyocyte injury resulting from cardiac disease was a major contributor to elevated troponin T and I concentrations even in these patients with skeletal muscle disorders. But troponin T concentrations were above the upper limit of normal in about 55% and the concentrations were significantly higher compared with control subs checked. While troponin I concentrations were elevated to a significantly lower percentage, which were also comparable to the concentrations in the control group. Also, we found that the elevated troponin T concentrations were restricted largely to patients with non-inflammatory myosis and myositis. And maybe one thing to the gene expression regarding the gene expression analysis, we found the eightfold up regulation for the gene and coding for cardiac troponin T in skeletal muscle compared with controls without skeletal muscle disease. Dr. Peder Myhre: Wow, that is so great. So please let me try to summarize these important findings to the listeners. So you actually found in patients with skeletal muscle disease, a much higher level of troponin T compared to healthy controls or at least controls without myocardial infarction. And for troponin, these differences were not that pronounced. So that means gene, that troponin T in patients with certain types of skeletal muscle disease may be falsely positive. Is that correct? And how would you put these findings in relation to previous studies in the field and also perhaps some clinical implications of the findings? Dr. Jeanna du Fay de Lavallaz: So yeah, I think we can say that in the patient where that was the case, this is actually falsely positive because when we talk about cardiac troponin T, cardiac troponin, we expect it coming from the heart, certainly not from the muscle of the patients or at least it's what cardiologists have been trying to not diagnose in the past years by refining also the assays that we were using so that it doesn't cross-react with anything coming from a skeletal muscle. And I think regarding previous studies in the field, so we tackled, I believe several aspect with this paper that hadn't really been well investigated before. And our study design helped with that a lot. So first we included patients based on their complaints that was not a specific cohort with a certain type of disease. We really enrolled them if they presented with some muscle complaints, so not a specific already diagnosed disease. So this was the first point. And then second also, we investigated several troponin I assays, which also allowed us to have a broader observation of how this assay are actually interacting also with each other or how they relate to this troponin T assay, which is the only one existing. And then finally, I think this translational part with the MRN analysis really helped us to go back to the primary hypothesis, how does that work? Why is this the case at all? And finding this re-expression of the cardiac troponin T in the skeletal muscle really tells us that this might actually not be a problem with the assay itself but might really be that we have some cardiac troponin T circling in the blood and being measured by a perfectly well working assay, which is a totally different mechanism than for instance, cross reaction that we might sometimes observe for instance, with troponin I assays. Dr. Peder Myhre: Exactly. And the findings were so consistent across the 3 troponin I assays and supported by the biopsy findings, I think they were so robust. And you know, we're talking about how this might impact adjudication of a suspected myocardial infarction, but also troponin is a very strong prognostic marker within chronic conditions and in ambulatory patients. And even there it may really impact the utility of troponin as a risk marker. Alexandra, don't you think so? Dr. Alexandra Prepoudis: So, to come back to the first part of your question, what about patients with myocardial infarction? Our study did not directly investigate the impact of these unexpected troponin T concentrations on the diagnosis of myocardial infarction. But we believe that it's reasonable to say that if patients with a known chronic skeletal muscle disease present with chest pain to for example the emergency department and the first troponin T comes back elevated, the clinician should be aware that the skeletal muscle can be a possible source of this biomarker. So if possible, a troponin I should be obtained in these patients. Dr. Peder Myhre: Excellent. And that brings us to the last question of today, I think Jeanne, and that is the future direction of this field. We now know, I think for certain that some skeletal muscle disease have an elevated cardiac troponin T, or perhaps not cardiac, but at least troponin T. So what do we need to learn more about this? And is there any way we can improve the assays? Please, Jeanne, let me know your thoughts about the future. Dr. Jeanna du Fay de Lavallaz: So that's a complex question. I think already we are kind of running into troubles when we already just see the current situation with these assays. Depending on the countries, depending on the hospitals, depending on the laboratory background that all the laboratory measurement system that we might have. Some hospitals have a total different approach on which troponin to measure and what's troponin to make available for their physicians. But I think these biomarkers haven't finished to surprise us and also most likely to bring us some very good prognostic tools. And I believe once we can really refine the exact origin of which elevation in which patient and what this does imply for their prognosis, we might also be able to just predict much better where with our patients are going, what kind of diagnostic or treatments that we need to use in order to improve their life on the short and long term. So I have quite a lot of hope for these different assays to be better understood in the coming years. Dr. Peder Myhre: What a wonderful way to finalize this podcast. Jeanne and Alexandra, thank you so much for participating and for sharing your knowledge in the field and to learn about your current situation with work and your choices of career. And also a big thank you to Francesca and Tanya for the winners of the LOSCALZO Award for sharing their research. So on behalf of Pishoy and myself, I want to thank everyone for listening and thank you to the amazing authors and winners of the awards. This is Peter Myra, and on behalf of myself and Pishoy Gouda, we thank you for listening. 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

    Circulation December 20, 2022 Issue

    Play Episode Listen Later Dec 19, 2022 18:44

    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

    Circulation December 13, 2022 Issue

    Play Episode Listen Later Dec 12, 2022 24:37

    This week, please join author Trisha Singh as she discusses her article "Manganese-Enhanced Magnetic Resonance Imaging in Takotsubo Syndrome." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass for the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Nam, 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, very interesting feature discussion this week. Many times we hear in magnetic resonance imaging the use of gadolinium contrast. And remember, gadolinium is an extracellular agent. And when we apply it in the heart, we look for infarcts, or areas of the heart that are perhaps dead, or scarred over. This week's feature discusses manganese as a contrast agent and it is an intracellular contrast agent. And very interestingly, it identifies calcium handling, so it's a marker of viability. And these authors are going to apply manganese as well as gadolinium in trying to understand mechanisms behind Takotsubo cardiomyopathy. 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? Dr. Carolyn Lam: Oh, I'd love to tell you about the other articles. But just have to first say, I loved your description of the feature paper. It's right up your alley and I can't wait to learn more. But my first paper today I want to talk about pulse field ablation. Now, what is that? Pulse field ablation, or PFA, is a unique and novel technique to treat atrial fibrillation. It has a unique safety profile largely related to its preferentially for myocardial tissue ablation. And thus, sparing the esophagus and thus, deemed to have a unique safety profile. Now, a pentaspline catheter was the first such PFA system studied for AF ablation. And in the initial trials the catheter was used for pulmonary vein isolation and left atrial posterior wall ablation. However, following its regulatory approval in Europe, in clinical practice, physicians have ablated both these locations and expanded lesions that could be in closer proximity to the coronary arteries. Now, this is an unstudied important issue since preclinical and maybe some clinical data have raised the potential for coronary arterial spasm. Hence, the investigators led by Dr. Vivek Reddy from Icahn School of Medicine at Mount Sinai and colleagues studied the vasal spastic potential of PFA lesion sets, both remote from and adjacent to coronary arteries. Dr. Greg Hundley: Wow, Carolyn, this is a really interesting question. So what did they find? Dr. Carolyn Lam: In this retrospective analysis of a series of 25 patients undergoing PFA for atrial fibrillation in whom coronary angiography was performed pre, during and post ablation, they found that during pulmonary vein isolation and left atrial posterior wall ablation, coronary spasm did not occur. However, cavotricuspid isthmus ablation provoked severe subtotal vasospasm in five out of five consecutive patients. And this was relieved by in coronary nitroglycerin. ST elevation was not observed. No patient had severe spasm if first pretreated with parenteral nitroglycerin, either intracoronary or intravenous. And so in summary, coronary vasospasm was not provoked during PFA at locations remote from the coronary arteries. But when the energy is delivered adjacent to a coronary artery, like in cavotricuspid isthmus ablation, PFA did provoke subclinical vasospasm. And the phenomenon was attenuated by nitroglycerine administered either post hoc to treat spasm or as prophylaxis. And this is discussed in accompanying editorial, I like it, “Coronary Vasospasm in PFA Primum Non Nocere” by Drs. Estes and Sundeep and Saba. Dr. Greg Hundley: Very nice Carolyn. Very important research in this area using that particular methodology. Well Carolyn, my next study comes to us again from preclinical science. And Carolyn, this study evaluated mechanisms responsible for pulmonary hypertension. So as background, pulmonary hypertension is associated with increased expression of VEGFA and it's receptor VEGFR-2. But whether and how activation of VEGFA signal participates in the pathogenesis of pulmonary hypertension, that's unclear. And so these authors led by Dr. Yangxin Chen from Sun Yat-Sen Memorial Hospital and Sun Yat-Sen University evaluated VEGFA, VEGFR-2 signal activation and VEGFR-2 Y949 dependent vascular leak in lung samples from patients with pulmonary hypertension as well as in mice exposed to hypoxia. Dr. Carolyn Lam: Another one of those excellent translational pieces, isn't it Greg? So what did they find? Dr. Greg Hundley: Right Carolyn. So these authors found that pulmonary hypertension led to excessive pulmonary vascular leak in both patients and hypoxic mice. And this was owing to over activated VEGFA and VEGFR-2 Y949 signaling axis. Abolishing VEGFR-2 Y949 signaling via a specific point mutation was sufficient to prevent pulmonary vascular permeability and inhibit macrophage infiltration and Rac1 activation in smooth muscle cells under hypoxia exposure. This, in turn, led to alleviation of pulmonary hypertension manifestations including muscularization of distal pulmonary arterials, elevation of right ventricular systolic pressure and right ventricular hypertrophy. And so Carolyn, in summary, these results suggest that VEGFA, VEGFR-2 Y949 dependent vascular permeability is an important determinant in the pathogenesis of pulmonary hypertension and might serve as an attractive therapeutic target pathway for this disease. Dr. Carolyn Lam: Aw, thanks Greg for explaining that so well. The next paper talks about transcatheter aortic valve replacement of TAVR, recognizing that it is a well established treatment now for high and intermediate risk patients with severe symptomatic aortic stenosis. However, the question asked here is what makes some, but not all patients improve their left ventricular ejection fraction following TAVR associated after load reduction? Now, hypothesizing that circulating microRNAs may play a role here, the authors led by corresponding authors, Dr. Hosen and Jansen from University of Bonn and their colleagues profiled the differential expression of microRNAs in circulating extracellular vesicles in patients after TAVR. And in particular, the novel role of circulating microRNA 1225p in cardiomyocytes. Dr. Greg Hundley: Oh wow. So Carolyn, important study. So what did they find? Dr. Carolyn Lam: Well, first aortic stenosis increases circulating microRNA 1225p, which correlated with a lack of improvement of the EF in patients after TAVR. Extracellular vesicles harbored microRNA 1225p and facilitated its startling into the cardiomyocytes. Vesicular shuttling of this particular microRNA was regulated by a direct interaction with a multifunctional RNA binding protein called heterogeneous nuclear ribonucleoprotein U in a sequence specific manner. Extracellular vesicles containing the specific microRNA post transcriptionally repressed BCL2 an anti-apoptotic gene, which is central to cell viability and apoptosis. So in summary, Greg, an increase in extracellular vesicle microRNA 1225p in patients with aortic stenosis represents a novel mechanism for the deterioration of cardiac function in patients following TAVR. And pharmacological manipulation of this axis may improve ejection fraction and cardiac function in patients with aortic stenosis by improving the viability of cardiomyocytes, which opens the door to a potential therapeutic approach in patients with limited EF improvement following TAVR. Dr. Greg Hundley: Oh Carolyn, beautiful, beautiful description of that wonderful preclinical science. Well, let's reach into the mail bag and see what else is in the issue. And first, there's a research letter by Professor van Raalte entitled “Kidney Hemodynamic Effects of Angiotensin Receptor Blockades Sodium Glucose Co-transporter 2 Inhibition Alone and in Their Combination: A Crossover Randomized Trial in People with Type 2 Diabetes.” And Carolyn, there's also an In Depth piece from Dr. Marx entitled “GLP1 Receptor Agonist for the Reduction of Atherosclerotic Cardiovascular Risk in Patients with Type 2 Diabetes.” Dr. Carolyn Lam: Very, very nice papers, those two. There's also an exchange of letters between Drs. Hou and Sedej regarding the article, “Fine Tuning Cardiac Insulin Like Growth Factor 1 Receptor Signaling to Promote Health and Longevity.” As well as a Perspective by Dr. Eagle, “Comments on the 2022 Aortic Guidelines: Seeking More Precision in Aortic Care.” Now, let's go onto the feature discussion of all things MRI, shall we? Dr. Greg Hundley: You bet. More on manganese. Welcome listeners to this very interesting feature discussion on December 13th. And we have with us Dr. Trisha Singh from the University of Edinburgh in Edinburgh, Scotland. Welcome, Trisha. This is a fascinating study incorporating manganese cardiovascular magnetic resonance to study some of the mechanistic underpinnings of hypokinesis left ventricular hypokinesis in patients with Takotsubo syndrome. So maybe just 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. Trisha Singh: Yes, of course. So we know with patients with Takotsubo syndrome, it predominantly affects middle aged women, patients present with a degree of left ventricular dysfunction, which is transient. And, unfortunately, it can be quite difficult to diagnose because it can phenotypically present very similar to an acute coronary syndrome. We know from previous studies that these patients do have ongoing symptoms despite normalization of their LV function. And actually their outcomes are not as benign as previously thought. In terms of manganese enhanced MRI imaging, we at Edinburgh University have imaged patients with other cardiac conditions such as hypertrophic cardiomyopathy, and dilated cardiomyopathy. And have established that it can be used as a surrogate marker of myocardial calcium uptake and handling. So we were very interested to see whether or not patients with acute Takotsubo syndrome have got a myocardial calcium dysfunction and more importantly whether or not this translates into long-term dysfunction and perhaps could explain their symptoms and worse prognosis in long-term. Dr. Greg Hundley: Trisha, manganese MRI. Now, we hear about gadolinium MRI, how is manganese different? You mentioned it's a nice marker for calcium handling. Is this widely used clinically? What kind of contrast does it provide? Dr. Trisha Singh: So manganese was actually one of the first contrast agents to be used with magnetic resonance imaging. It kind of came about in the 1970s and 1980s. And previous animal models have looked at how it is essentially an intracellular contrast agent. And what I mean by that is manganese is a calcium analog and therefore, in cells where they are viable and there's intact cell function, they will be taken up through a voltage gated calcium channels. So, for example, in the heart. So the theory is that manganese, when you've got normal viability, manganese is taken up into the myocardium via voltage gate calcium channels. And several studies have shown that if you then have disease myocardium, these tissues do not take up the manganese as normal tissue would. And the main difference between manganese and gadolinium is they are both paramagnetic, which is why they're helpful and useful in MRI. But gadolinium, as a compound, is too big and it cannot cross an intact cell membrane and therefore, gadolinium is more extracellular. And as, we know, accumulates in tissues where there is increased edema, or water content. So gadolinium, for all intents and purposes, is incredibly useful contrast agent, certainly what we use predominantly at the moment in clinical practice, but it is extracellular. So the theory behind manganese is that it is an intracellular contrast agent as opposed to gadolinium. And where gadolinium accumulates in disease tissue, manganese accumulates in viable tissue. So they behave almost kind of in contrast to each other. And currently, manganese is not used in clinical practice. I think the only clinical compound contrast agent utilizing manganese was mangafodipir, otherwise known as Teslascan, which I believe came off the market in 2012 and that was predominantly used for imaging liver metastasis. Dr. Greg Hundley: Well Trisha, thank you for clarifying for us the difference between manganese, the intracellular contrast agent, and gadolinium, the extracellular contrast agent, that's so widely used clinically. Well, with that description, can you describe for us now, your study population and your study design? Dr. Trisha Singh: Perfect. So the study population was we aimed to recruit 20 patients with acute Takotsubo syndrome. The diagnosis of Takotsubo syndrome was based on a clinical diagnosis, so all our patients underwent a baseline echocardiography and invasive coronary angiography. Now, for us, the coronary angiography was quite important because we wanted to ensure we ruled out anyone with an acute myocardial infarction, which can often be tricky in this cohort of patients. So after recruiting 20 patients during the acute phase of Takotsubo, they all underwent a baseline gadolinium enhanced MRI scan followed by a manganese enhanced MRI scan. And these were done at least 48 hours a part. And then about three months roughly after the acute index, they were all invited to participate in a second manganese enhanced MRI scan. Dr. Greg Hundley: Very good. So two exams separated longitudinally over time. What were your study results? Dr. Trisha Singh: Our results demonstrated that during the acute phase as one would expect, patients had a degree of left ventricular dysfunction. The majority of our patients had afibrillar Takotsubo, so had afibrillar ballooning with preservation of the basal segments. With this, we also noted that in the areas that were affected by Takotsubo, so kind of the mid ventricular wall and the apex that all patients had significantly elevated native T1 and associated T2 as well. And as we expected there was reduced uptake of manganese and therefore kind of reduced calcium uptake in the myocardium in the area affected by Takotsubo syndrome. Interesting, what we also noticed was that all these patients had significantly elevated LV mass, which has been described in previous Takotsubo papers, certainly by Professor Dawson. And when you measured the left ventricular wall thickness, the LV wall thickness is elevated in the affected and actually not even in the non-affected areas, which I suspect explains why in the acute phase people almost doubles up which kind I guess fit with kind of acute myocardial edema and intense water content. And then, three months later when these patients returned for their follow-up scan, a lot of the acute changes had resolved. So native T2 values had improved and gone back to baseline. Native T1 and post contrast T1 values had remained elevated compared to the control population. And what we found was that manganese uptake, though it had improved, it still remained abnormal and reduced compared to the control population, which is a finding that we weren't expecting to find. Dr. Greg Hundley: Very interesting. So acutely we've got extracellular water there, elevation of myocardial T2, and also impaired manganese uptake. So intracellular abnormalities with calcium handling. Then later, so three months later, we have restoration of myocardial T2 so the extra water content is absent, but we have impaired manganese uptake indicating an abnormality with calcium handling. So how do we put this all together mechanistically? What does this tell us about the pathophysiology of Takotsubo syndrome? Dr. Trisha Singh: For one thing, I think we can say that there is, as described before, there is obviously intense myocardial edema present in patients with acute Takotsubo. And I think the significant elevation in T2 and LV mass kind of all fits together. Actually interestingly, as native T2 improves in their follow-up scans, the LV mass actually all return back to normal baseline. So I think the acute edema does resolve. And as you said, interestingly, despite all of these patients, their LV function completely recover. And despite that their myocardial calcium uptake, or handling remain normal. And I think that's not been demonstrated before. And I think it just points to that there is obviously, still something going on in the myocardium and it's not behaving completely normally despite completely normal kind of gross LV function. And potentially, this might point in the direction of why these patients have ongoing symptoms. So, certainly, from our observational cohort group, about 70% of patients had ongoing symptoms and this was predominantly breathlessness and palpitations. And potentially, might be related to why patients have worse outcomes compared to the general population. Dr. Greg Hundley: Very nice. And Trisha, can you describe, was there a therapeutic intervention between the acute and then the three month later measurements? Were these patients administered any type of medical therapy and were there differences in what those therapies may have been between different patients in your study? Dr. Trisha Singh: So predominantly, most of the patient population that were started on some combination of heart treatment due to the baseline LV dysfunction. And this kind of was a combination of most of them were on Ramipril, a few of them were also on spironolactone or eplerenone. And then, every single one was on furosemide. And interestingly, I mean I appreciate, I think the population group was quite small, so it's very difficult to compare those that were on kind of full heart failure treatment versus those who were just on beta blocker and ramipril therapy. But even in that cohort there was a split of about, I think predominantly, I think 17, 16 patients were on kind just beta blockers and ramipril as opposed to beta blocker, ramipril, spironolactone. And there was no difference kind of in the recovery in manganese uptake in that cohort. But, again, the numbers are quite small, so I think it's difficult to extrapolate any kind of true meaning in that. Of course, we know there's a lack of randomized control trial data looking at how to best treat patients with acute Takotsubo syndrome and certainly, what treatment may prevent these patients from having a recurrence of Takotsubo. And I know some of the TACA registry data has looked at actually despite the fact patients of being on beta blocker, or ramipril therapy, they still go having recurrence of Takotsubo and certainly of our cohort, one of our patients went on having a recurrent episode of Takotsubo within a year of her index event and she was on aspirin, beta blocker, spironolactone as well. Dr. Greg Hundley: Very nice. And then lastly, when you made these measurements looking at the manganese uptake or lack thereof, were these in the regions of myocardium where you mentioned many had apical LV wall motion abnormalities, were they in those regions or did you also measure regions remote to where the wall motion abnormality occurred? Dr. Trisha Singh: Of course. So we took measurements in the affected regions of the heart that kind of demonstrated spironolactone syndrome. And we also took measurements in kind of, so to speak, the remote segments of the heart. Now, for the remote segments of the heart, we could only measure native T1 and post contrast T1 at 30 minutes and to measure manganese uptake well, unfortunately, what we have to do is take a measurement over time, so we'd do every two and a half minutes for 30 minutes after the manganese contrast. So we weren't able to calculate manganese uptake in the remote regions. But what we could do was measure the native T1 in the remote region, and then the post contrast T1 and see how it differed with the region of interest in the affected portion of the heart, so to speak. Dr. Greg Hundley: Very good. Well, Trisha, with this really exciting research and very nice methodology, what do you see as the next study to be performed in patients with Takotsubo? Dr. Trisha Singh: So I think, in terms of manganese enhanced imaging, I think it'd be really interesting to re-scan these patients at one year or at two years. And the question there is whether or not their manganese uptake ever recovers really. I know we previously talked about this and thought about whether or not these patients who go onto developing Takotsubo syndrome might actually have a kind of an underlying cardiomyopathy that puts them at risk of developing Takotsubo with stress. So it'd be interesting to see whether or not actually their calcium uptake ever recovers in the long-term, or whether actually they have more of a chronic heart failure type like picture. And I think another area of interest would be to see potentially using manganese imaging as a noninvasive measure of kind of myocardial calcium activity and to see whether or there's any changes with therapy over the course of months to years or so. Dr. Greg Hundley: Very nice. Well listeners, we want to thank Dr. Trisha Singh from University of Edinburgh in Edinburgh, Scotland for bringing us this really interesting article in patients with Takotsubo syndrome demonstrating that there is a marked perturbation of myocardial manganese uptake, which is most evident in the acute phase of Takotsubo presentation, but also persists for at least three months despite apparent restoration of normal left ventricular ejection fraction and resolution of myocardial edema. All of this suggesting that abnormal myocardial calcium handling may be implicated in the pathophysiology of Takotsubo syndrome. 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

    Circulation December 6, 2022 Issue

    Play Episode Listen Later Dec 5, 2022 21:42

    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

    Circulation November 29, 2022 Issue

    Play Episode Listen Later Nov 28, 2022 25:17

    This week, please author Gemma Figtree and Associate Editor Nicholas Mills as they discuss the Frontiers article "Noninvasive Plaque Imaging to Accelerate Coronary Artery Disease Drug Development." Dr. Greg Hundley: Welcome listeners to this November 29th, 2022 issue of Circulation On the Run. I am one of your hosts, Dr. Greg Hundley, director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Peder Myhre: I am Dr. Peder Myhre from Akershus University Hospital and University of Oslo in Norway. Dr. Greg Hundley: Well, Peder this week's feature discussion very interesting. It is a state of the art review and it involves noninvasive plaque imaging and really how we might assess plaques to evaluate whether coronary artery disease is accelerating. Very important information by a large group of clinician scientists that will develop programs that, maybe, can be used in therapeutic drug development. Dr. Peder Myhre: That's so interesting, Greg. Dr. Greg Hundley: Right. A great group of individuals all put together, but before we get to that interesting feature discussion how about we grab a cup of coffee and start with some of the other articles in the issue? How about this week I go first? Dr. Peder Myhre: Go ahead Greg. Dr. Greg Hundley: Peder, these authors led by Marianna Fontana from University College London Medical School sought to characterize changes in the clinical phenotype of 1,967 patients with a diagnosis of transthyretin cardiac amyloidosis over the last 20 years enrolled and participating in the National Amyloidosis Center from 2002 to 2021. Dr. Peder Myhre: Oh yes, Greg, please. This cardiac amyloidosis we have to learn more about it. Please, tell me what did they find. Dr. Greg Hundley: Right, Peder. First, there's been a substantial increase in the number of patients diagnosed with transthyretin amyloid in recent years. This is associated with greater proportions of patients referred following cardiovascular magnetic resonance imaging and bone scintigraphy scans. Second, transthyretin amyloid patients are often now being diagnosed much earlier in their disease process, as evidenced by a shorter duration of symptoms prior to diagnosis, milder stages of disease, and more favorable structural and functional echocardiographic changes at the time of diagnosis. Then, finally, mortality in these transthyretin amyloids patients has improved substantially in recent times aside from any potential benefits from disease modifying treatment or participation in clinical trials. Dr. Peder Myhre: Wow. Greg, over the course of 20 years we have seen some differences in the diagnosis or cardiac ATTR amyloidosis, so what would you say are the take home messages from this paper, Greg? Dr. Greg Hundley: Right, Peder. Transthyretin amyloid is now often diagnosed earlier in the disease process with improved prognosis. I think, more data needed to guide decisions on in whom and when to initiate treatment and then which treatments should be used at each stage of the disease. Peder, along with this article there's an excellent editorial by Doctors Patel and Maurer entitled “The Future for Patients with Transthyretin Cardiac Amyloid is, It's Looking Brighter.” Dr. Peder Myhre: Okay. Greg, I'm going to continue in the field of clinical research and this paper actually describes a new ablation technique for ventricular tachycardia. Isn't that exciting? Dr. Greg Hundley: Absolutely. Dr. Peder Myhre: The paper comes to us from corresponding author Miguel Valderrabano from Houston Methodist Hospital in Texas and is entitled “Substrate Ablation by Multi-vein, Multi-balloon Coronary Venous Ethanol for Refractory Ventricular Tachycardia and Structural Heart Disease.” Ablation of ventricular tachycardia, VT, in the setting of structural heart disease often requires extensive substrate elimination, which is not always achievable by endocardial radiofrequency ablation and epicardial ablation is not always feasible. The left ventricle venous circulation allows vascular access to reach intramural substrates of VT in the context of myocardial infarction or non-ischemic scar, where radiofrequency ablation has limited success. Greg, in this study the authors enroll patients with ablation refractory VT and used phonography and epicardial mapping to perform a double balloon venous ethanol ablation. That is, by blocking flow with one balloon and injecting ethnol via this second balloon. Dr. Greg Hundley: Peder, what a beautiful description and very interesting strategy to address this situation. What did they find? Dr. Peder Myhre: Greg, after the venous ethanol ablation vein maps and epicardial maps showed elimination of abnormal electrograms of the VT substrate an intracardiac echocardiography demonstrated increased intramural echodensity at the target lesions of the 3D maps and at one year of follow up VT recurrence occurred in seven patients, which translates into a success rate of 84%. The authors conclude that multi-balloon multi-vein intramural ablation by venous ethanol ablation can provide effective substrate ablation in patients with ablation refractory VT in the setting of structural heart disease over a broad range of left ventricular locations. Dr. Greg Hundley: Very nice, Peder. What a beautiful description. Excellent. Well, this next paper Peder comes to us from the world of preclinical science and these authors led by Professor Christine Sideman from the Harvard Medical School evaluated alpha-kinase 3. Now, alpha-kinase three is a muscle specific protein in which loss of function variants cause cardiomyopathy with distinctive clinical manifestations in both children and adults. At presence the muscular functions of alpha-kinase 3 remain poorly understood, so to address this dilemma these investigators explored the punitive kinase activity of alpha-kinase 3 and the consequences of damaging variants using isogenic human induced pluripotent stem cell derived cardiomyocytes. Mice and human patient tissues. Dr. Peder Myhre: Okay, Greg. This sounds like impressive basic science work, so what did the authors find. Dr. Greg Hundley: Right, Peder. Damaging variance in alpha-kinase 3 encoding an abundant muscle specific protein caused both neonatal and adult onset cardiomyopathies and led to both ventricular dilation and hypertrophy. Now, although alpha-kinase three contain an alpha kinase domain the team showed that it lacks catalytic activity and is really a pseudo kinase. Then finally, Peder, alpha-kinase 3 localizes to both the nuclear envelope of cardiomyocytes and the M-band of the sarcomere where it regulates the expression and localization of myomesins, myomesin 1 and myomesin 2, and additional M-band proteins important for sarcomere protein turnover. Dr. Peder Myhre: That is a beautiful summary, Greg. Since you did so well at summarizing this difficult topic, I'm not going to ask you what a clinical implications, but rather to take home messages here. Dr. Greg Hundley: Very nice. Glad you asked Peder. First, alpha-kinase 3 cardiomyopathy may cause impaired contractility and ventricular dilation due to miss localization and dysregulation of myomesin proteins which are critical for force buffering in cardiomyocytes. Next, alpha-kinase 3 cardiomyopathy may cause hypertrophy due to dysregulation of key M-band proteins, which are important for sarcomere protein turnover. Then finally, therapeutic strategies to restore cardiomyocyte force buffering functions and sarcomere protein turnover may ameliorate disease phenotypes in patients with alpha-kinase three cardiomyopathy. Dr. Peder Myhre: Thank you Greg. The next paper is also from the field of preclinical science and it is about the Hippo-YAP signaling pathway which maintains sinal atrial node homeostasis. It comes to us from the corresponding author Jun Wang from the University of Texas Health Science Center at Houston. Greg, this paper is not about hippos, but it is about the Hippo signaling pathway, which is known to control organ size and growth in animals and humans. These authors sought to investigate this pathway in relation to the sinal atrial node, i.e. The sinus node. As you know Greg, the sinal atrial node functions as the pacemaker of the heart initiating rhythmic heartbeats. Despite its importance the sinal atrial node is one of the most poorly understood cardiac entities, because of its small size and complex composition and function. To uncover the function of Hippo signaling in sinal atrial node the authors use knockout mice and a series of physiological and molecular experiments including telemetry, electrocardiogram recording, echochoreography, calcium imaging, immunostaining, ANA scope, quantitative real time PCR, and western blotting. Dr. Greg Hundley: Wow, Peder, that sounds like quite an extensive series of experiments. What did they find? Dr. Peder Myhre: Deletion of essential Hippo kinases caused increased fibroblast proliferation and fibrosis in the sinal atrial node. They also found evidence suggesting that Hippo signaling regulates calcium hemostasis in pacemaker cells and that may be partially mediated by the regulation of genes and coding key calcium handling proteins such as RYR2. Finally, the demonstrated that deletion of Hippo effectors in the sin atrial node can rescue the defect previously described. Greg, the take home messages is that Hippo signaling was found to be an important regulator of the sinal atrial node homeostasis and that this provide insights applicable to the treatment of patients with sinus node dysfunction. Dr. Greg Hundley: Ah, beautifully done Peder. Beautifully done. We've got some other articles in this issue. Let me tell you about a Research Letter. It's from Professor Nazer entitled “Targeted Screening for Transthyretin Amyloid Cardiomyopathy in Patients with Atrial Fibrillation.” Then Tracy Hampton has a whole series of cardiology news highlighting first that primary cilia are critical for exercise induced muscle hypertrophy. This is from the proceedings of the National Academy of Sciences. Next, there's a discussion of whole body reperfusion techniques to restore function in pig organs after death, that comes to us from nature. Then lastly, there's a final article scientists identify diverse pathogenic gene variants that lead to heart failure from the journal science. Dr. Peder Myhre: Thank you, Greg. Finally, there is one Perspective piece by Dr. Rajiv Agarwal from Indiana University School of Medicine entitled “Hydrochlorothiazide versus Chlorthalidone: What is the difference?” Now, let's move on to the feature discussion that I know you are very excited about, Greg, to learn more about the non-invasive plaque imaging in our frontiers of medicine.   Dr. Greg Hundley: You bet. Well listeners, welcome to this feature discussion today on November 29th and we have with us Dr. Gemma Figtree from Sydney, Australia and our own associate editor, Dr. Nick Mills from Edinburgh, Scotland. Welcome to you both. Listeners, this is a really interesting feature discussion. It's one of our Frontiers articles that combines where we are in the past, but also where we want to move in the future and a very nice comprehensive review with many articles. Gemma, can you describe for us the genesis really of this article and what you've been working on? Dr. Gemma Figtree: Thanks so much, Greg. Look, I think it's very exciting times at the moment and it's a really important time for all of our community to actually get together in this space. We are driven by trying to make a more efficient process for drug discovery and translation to occur and to basically move into humans in the space of coronary artery disease. We've actually known, obviously, for a long time that the underlying process driving heart attack, but we've not been able to image and treat the actual underlying disease. What this article focuses on is how we actually merge top current technology with policy and approval of drugs. We are very excited about the team of over 20 different institutes around the world trying to work on the best measures of corona artery disease as the disease itself. Dr. Greg Hundley: Very nice. Now, help us understand different techniques and why is this a frontier? Dr. Gemma Figtree: Look, I think it's a mixture of the fact that, obviously, we're getting great advances in noninvasive imaging techniques that allow us to actually measure plaque burden, but also plaque characteristics. In the case of drug translation this is an absolutely fundamental piece. You can transform a clinical trial where you can look at the underlying pathology and be able to enrich trials or be able to look at the effect of trials of a new drug in humans. It's really important to acknowledge the fact that humans are really the only animal on the planet that get corona artery disease itself. To be able to translate some of the exciting new drugs that target the plaque itself and work synergistically with some of our agents on cholesterol, and blood pressure, et cetera, we really need to have these measures of coronary artery disease itself. It's a combination of the technology, but also how we apply it to a clinical trial and then how do we work with our regulatory authorities and policy advisors around getting this into humans. We really aiming to try to accelerate the development of drugs that can try to tackle our greatest burden of cardiovascular disease around the world. Dr. Greg Hundley: I'm hearing cardiovascular disease, I also heard in their imaging and lots of different modalities, and then I heard regulatory bodies. Are you thinking maybe we need standards? Dr. Gemma Figtree: That's exactly right. I think, importantly, whilst there's a lot of exciting technology and a lot of us are pursuing potentially different avenues of this we also need to be able to coordinate and develop a simple and harmonized approach that's able to be applied across the world in an equitable fashion. Whilst we, obviously, have developing exciting new toys we have to make sure that a measure that we want to work with regulatory authorities is able to be applied in all of our countries around the world to make sure that the drug development is applied in an equitable fashion. Dr. Greg Hundley: Very nice. Well listeners, next we're going to turn to our associate editor, Dr. Nick Mills. Nick, you evaluate many manuscripts. What attracted you to this particular paper? Also, help us put it in the context of why you think it's a new frontier that is emerging or needs to emerge in cardiovascular disease. Dr. Nick Mills: Yeah, thanks Greg. Three things, the expertise of this group, the focus and novelty of the topic, and the fact that it's a really timely issue Gemma just outlined. Gemma a phenomenal job bringing together people from all over the world to tackle this area that includes imaging expertise, drug development expertise, industry that gives it a very balanced and diverse range of views and marks it out from other reviews that focus on particular imaging modality. Novelty's really important, but timeliness as well. We've seen in the last five years major breakthroughs in the treatment of diabetes and heart failure. But, drug development of coronary heart disease is stalling. I cannot remember the last time I went to a really exciting late breaking trial on a new development for coronary heart disease that has changed the outcomes for patients. We do need to rethink. Gemma's absolutely right, that requires us to work with regulators to stimulate industry involvement in drug discovery, and delivery, and testing. This is occurring at a time where we've got more fabulous imaging modalities then we've ever had before. Critically, they're noninvasive. They're easy for patients, they're easy for serial testing, and that really opens up many opportunities. It's the fact that it's timely, novel, great expertise, and also really exciting area for cardio of medicine. Dr. Greg Hundley: Very nice. Well listeners, we're going to go back to Gemma. Gemma, what do you think are some of the next research studies that we need to perform to support what we're trying to indicate today in this Frontiers article? Dr. Gemma Figtree: Yeah. Thanks very much, Greg. I think, ultimately, the features that need to be taken into consideration for a surrogate endpoint to be approved by our regulatory authorities need to be considered. There are many drug companies, but also individual investigators with ideas of drugs to take forward. What we need to do is make sure for all those studies that we're actually working together and ideally having a harmonized endpoint for use there. I think, working early with regulatory authorities is going to be key. I think, if you actually, within the tables that are presented in the paper we demonstrate very clearly that these measures of plaque, particularly, the CT coronary angiography measures of low attenuation plaque are pretty ready for consideration by regulatory authorities. I think, agents that we already know work to reduce mortality, such as statins, we know that they actually have direct effects on plaque both from a pathophysiological perspective, but also from these imaging studies. We know that that change in the plaque characteristics and volume predict the outcomes. In a sense, we've got a fabulous array of data already. In fact, new agents that have come through have also demonstrated effects on these measures. I think, by bringing all of this together in this article we're already in a position to work with regulatory authorities to see what is needed next. I think, listening to that's going to be very important. I do think that the next steps are really going to be working with effectively, I guess, our colleagues to make sure that we don't continue to rapidly advance the measures whilst losing the opportunity to work with regulatory authorities. In answer your question about the research side of things, I think, as we gather more and more information about this we have to make sure that phase two studies are then linked and we can retrospectively see how they predict the outcomes in phase three studies, but I firmly believe that we're in a position that over the next couple of years we should be able to do harmonized approaches at phase two studies and then as a whole community be able to look at how that predicts outcome and work with our regulatory authorities to get more confidence in these endpoints as key. This is all driven by my clinical observations and interest in people who look up and say, "Why me" when they're having a heart attack? In our community where we're getting very good primary prevention we see up to 25% of our heart attack patients having plaque events and catastrophic heart attacks without those traditional risk factors that would've worn them. Part of this is also opening up avenues for driving new diagnostic tools that can pick up the disease itself. Picking up... Treating coronary disease as the disease and using that for diagnostic and therapeutic purposes, I think, is a great opportunity to tackle this great burden that we're currently not winning with. Dr. Greg Hundley: With the group that you had assembled were there any primary suggestions on how to unite some of these efforts on a global scale? I really liked, very early in our conversation today, you mentioned that and I wondered what this collective you assembled may have suggested. Dr. Gemma Figtree: Yeah. Look, I think at the moment it is a collection of experts. I haven't quite figured out the name for such a thing, but we are also working with some of the leading organizations now to try to also make sure we get their auspicing of the concepts and how to best do that. I think, by not coming out of one particular organization and evolving from the members itself, and in particular, having industry and regulatory authorities involve and drug discovery experts right from the beginning has been fantastic. Also, making sure that we have that pragmatic approach and that consideration of equitable access. Particularly, making sure that any phase two trial can be done or enrichment for phase three trial can be applied right around the globe and make sure we get diversity of patients enrolled in these studies. Dr. Greg Hundley: Very nice. Coming back to you, Nick, any additional thoughts to build on Gemma's comments here? Dr. Nick Mills: Well, to say as someone who's worked in the field of cardiac biomarkers for many years and felt that we could tackle this with the regulators and drug delivery, but I've seen inflammatory biomarkers, lipoproteins come and go without changing. I think, it's just a really exciting opportunity that we now have the ability to phenotype an image, coronary artery disease noninvasively, but a highly specific surrogate endpoint that we've never had before. It's why I'm starting to do research into DT. Dr. Greg Hundley: Very nice. Well listeners, we want to thank Dr. Gemma Figtree from Sydney, Australia and our own associate editor, Dr. Nick Mills for bringing us this really provocative Frontiers article highlighting a new strategy. Bringing together regulators, leading researchers, and industry to advance new methodologies and trying to tackle globally how we might address atherosclerosis. 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 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

    Circulation November 22, 2022 Issue

    Play Episode Listen Later Nov 21, 2022 19:50

    This week, please author Jung-Minh Ahn and Associate Editor Emmanouil Brilakis as they discuss the article "Everolimus-Eluting Stents or Bypass Surgery for Multivessel Coronary Artery Disease: Extended Follow-Up Outcomes of Multicenter Randomized Controlled BEST Trial." Dr. Greg Hundley: Welcome, listeners to this November 22 issue of Circulation on the Run. And I am 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 University of Oslo in Norway, and also a social media editor interpolation. Dr. Greg Hundley: Well Peder, our feature this week, we are reviewing a comparison between drug eluting stents and bypass surgery for multi vessel coronary artery disease. Really an extended follow up from the Vest trial. Dr. Peder Myhre: I can't wait, Greg. Dr. Greg Hundley: Right. But before we get onto that, how about we grab a cup of coffee and jump into some of the other articles in the issue? Would you like to go first? Dr. Peder Myhre: Sure, I'd love to. And the first paper today is a clinical one and it is entitled, “Efficacy of a Drug Eluting Stent Versus Bare Metal Stents for Symptomatic Femoropopliteal Peripheral Artery Disease: Primary Results of the Eminent Randomized Trial.” And it comes to us from the corresponding author Yann Gouëffic from Groupe Hospitalier Paris St. Joseph in France. So Greg, a clear patency benefit of a drug eluting stent over bare metal stents for treating peripheral artery disease of the femoropopliteal segment has not been definitely demonstrated. But today's paper publishes the primary results of the eminent randomized trials, which was designed to evaluate the patency of the Eluvia drug eluting stent. And this stent is a polymer based paclitaxel eluting stent and it was compared with bare metal stents for the treatment of femoropopliteal artery lesions. In fact, with 775 patients, Eminent is the largest randomized trial of drug eluting stent treatment for symptomatic femoropopliteal arterial disease to report patency to dates. Dr. Greg Hundley: Very nice, Peder. So describe for us, what were the results of this very large randomized clinical trial? Dr. Peder Myhre: Sure, Greg. So the primary effectivity outcome was primary patency at 12 months, defined as independent core laboratory assessed duplex ultrasound peak systolic velocity ratio less than or equal to 2.4 in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesions. And primary effectiveness analysis from the Eminent randomized study demonstrated superior one year primary patency for the Eluvia drug eluting stent versus bare metal stent. And that is 83.2% versus 74.3% with a P value less than 0.01. And this treatment was associated with a greater incident of Rutherford classification improvement without the need for re-intervention, and functional parameters demonstrated improvements in both groups, and there were no statistical difference observed in one year mortality between patients treated with the Eluvia drug eluting stents and bare metal stents. So in summary, this high level evidence supports the one year benefit of polymer based paclitaxel elusion over bare metal stents to treat superficial femoral artery and/or proximal popliteal artery lesions. What'd you think of that, Greg? Dr. Greg Hundley: Very nice. So sounds like for peripheral arterial interventions, a benefit from the polymer based paclitaxel eluting stents. Dr. Peder Myhre: Exactly. And there's also an editorial putting these results in context from Doctors Mosarla and Secemsky entitled, “From Imperialism to Eminence: The Noble Rise of the Second Generation Peripheral Drug Eluting Stents.” Dr. Greg Hundley: Excellent, Peder. Well, my article comes to us, Peder, from the world of preclinical science. And Peder, these investigators led by Professor Volker Spindler from University of Basel evaluated arrhythmogenic cardiomyopathy. And as you know, arrhythmogenic cardiomyopathy is characterized by progressive loss of cardiomyocytes with fibrofatty tissue replacement, systolic dysfunction, and life threatening arrhythmias. So a substantial proportion of arrhythmogenic cardiomyopathy is caused by mutations in genes of the desmosomal cell to cell adhesion complex, but the underlying mechanisms are not well understood. So to address this, the team mutated the binding site of desmoglein two, a crucial desmosomal adhesion molecule in cardiomyocytes. This desmoglein two W2A mutation abrogates the tryptophan swab, a central interaction mechanism of desmogenin two based on structural data. Now, the impaired adhesive function of this DSG2W2A was confirmed by cell to cell dissociation assays and for spectroscopy measurements by atomic force microscopy. Dr. Peder Myhre: Wow. We continue to learn more about this disease, arrhythmogenic cardiomyopathy. And this sounds so interesting. Greg, please tell me what did they find? Dr. Greg Hundley: Right, Peder. So they found that the DSG2W2A mutation impaired binding on the molecular level and compromised intercellular adhesive function. Now, mice bearing this mutation, developed a severe cardiac phenotype recalling the characteristics of arrhythmogenic cardiomyopathy including cardiac fibrosis, impaired systolic function, and arrhythmia. Now, a comparison of the transcriptome of the mutant mice with arrhythmogenic cardiomyopathy patient data suggested deregulated integrin alpha V beta six and subsequent TGF beta signaling as a driver of cardiac fibrosis. Now accordingly, blocking integrin alpha V beta six led to reduced expression of pro-fibrotic markers and reduced fibrosis formation in the mutant animals in vivo. Dr. Peder Myhre: Oh, this is so important mechanistically. And Greg, can you please tell us something about the clinical importance of these findings? Dr. Greg Hundley: Right Peder, just like Carolyn always driving at that clinical significance. So these authors show now that disruption of desmosomal adhesion is sufficient to induce a phenotype which fulfills the clinical criteria to establish the diagnosis of arrhythmogenic cardiomyopathy confirming the dysfunctional adhesion hypothesis. Now mechanistically, deregulation of integrin alpha V beta six and TGF beta signaling was identified as a central step in the process toward developing fibrosis. And then finally, a pilot in vivo drug test revealed this pathway as a promising target to ameliorate fibrosis. So perhaps, new information leading to future therapeutic strategies to halt myocardial fibrosis in patients with arrhythmogenic cardiomyopathy. Dr. Peder Myhre: Oh wow. What an amazing issue this is, Greg, and we actually have even more in the mail bag. We have a Perspective piece by Dr. Prystowsky entitled “Rate versus Rhythm Control for Atrial Fibrillation, Has the Debate Been Settled?” And we have some Cardiology News by Bridget Kuehn entitled, “Fitness Rather than BMI Appears to be Better Predictor of Survival for Women with Heart Disease.” I'm sure Carolyn would love to read that one. And in this paper, Bridget Kuehn discusses a new study published in European Journal of Preventive Cardiology. Dr. Greg Hundley: Very nice, Peder. Well, I've got a couple other articles in the issue. First, Dr. Tonelli has a Primer entitled, “Increasing Societal Benefit from Cardiovascular Drugs.” And then Professor Januzzi has a Research Letter entitled, “Association Between Sacubitril/Valsartan Initiation in Mitral Regurgitation Severity and Heart Failure with Reduced Ejection Fraction: The PROVE HF Study.” Well, now let's get on to that feature discussion in this issue to discuss PCI versus CABG for multi vessel coronary artery disease. Dr. Peder Myhre: Let's go. Dr. Greg Hundley: Welcome listeners to this November 22nd feature discussion and we have with us today Dr. Jung-Min Ahn from Seoul, South Korea and our own associate editor, Dr. Manos Brilakis from Minneapolis, Minnesota. Welcome gentlemen. Jung-Min, 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. Jung-Min Ahn: Thank you, Greg. So the everolimus-eluting stent Freedom trial, showed a higher mortality after PCI than after bypass surgery in multi vessel disease. However, these findings maybe delimited predictability in the contemporary practice because such trials use the first generation drug stent which may have higher rate of stent thrombosis. The Press trial is the first randomized trial using the second-generation drug eluting stent. The initial approach was published in New England Journal of Medicine five years ago. So they showed that the 4.6 years of follow the PCI with everolimus-eluting stents showed a significantly higher rate of prime endpoint deaths, MI, the target revascularization, but overall mortality, there was no significant difference. So the hypothesis that, in a long term follow, more than 10 years follow, so we want to see the mortality difference between the PCI with the second generation everolimus-eluting stent versus bypass surgery. So we designed this extended follow trial best studies. Dr. Greg Hundley: Very nice, Jung-Min. And can you describe for us the study design, and who was your study population, and how many subjects did you enroll? Dr. Jung-Min Ahn: Actually, this study is the extended follow original Press trial, enrolled 880 patients from mostly Korea, China, Malaysia, and Thailand. So the study population was Asian population with a symptomatic or symptomatic coronary artery disease with angiopathy confirming the multi vessel coronary artery disease population. One additional criteria is the patient with coronary artery disease should report PCI and bypass surgery decided by the attending physicians and surgeons. Dr. Greg Hundley: Thank you, Jung-Min. And so, can you describe for us your study results? Dr. Jung-Min Ahn: Yes. During the extended follow-up study we found that there is no significant difference between the PCI with everolimus-eluting stent and bypass surgery regarding prime endpoint deaths, MI, vascularization. In addition, more importantly, we reduced the compost endpoint of death, MI, stroke. There was no significant difference in addition regarding the mortality. Also, there is no significant difference during the long term follow. Dr. Greg Hundley: Really interesting results, Jung-Min. Did you notice any differences in men versus women or in younger versus older individuals? Dr. Jung-Min Ahn: In our sub-group analysis, there is no interaction according to the sub-groups except the diabetic sub-groups. In diabetics and long term outcomes, have interaction with the treatment assignment regarding the primary endpoint, prime endpoints, death, MI, target vascularization. Even though contrary to the Freedom trial, the overall mortality rate, there is no significant difference between the PCI versus the bypass surgery even in diabetic populations. Dr. Greg Hundley: Well thank you so much, Jung-Min. And now listeners, we're going to turn to our Associate Editor, our expert in the area of advanced percutaneous coronary artery interventions, Dr. Manos Brilakis from Minneapolis, Minnesota. Manos, you have many papers come across your desk. What attracted you to this particular paper and how do you put its results in the context of other studies that have been performed to compare multi vessel percutaneous coronary artery intervention versus coronary artery bypass grafting? Dr. Manos Brilakis: Yeah, thank you, Greg. And again, congratulations to Jung-Min for a great paper. And the reason we were very interested in this paper is because it is an area that is still debated clinically quite extensively. As Jung-Minh mentioned, there is the Syndex trial showing that there was higher mortality amongst the PCI group over long term, but that was done a long time ago with previous generation drug diluting stents, and the data, the contemporary data with recently the currently used DS, is much more limited. So I think the appeal for us, and I think frankly for the practicing interventionalist, is that this paper provides long term outcomes with contemporary drug eluting stents over a fairly large patient population, and it does so fairly well, but there are plus and minuses. There was no difference in mortality, which continues to be debated. But this paper is fairly equivalent on this respect. And if we see the coupled myo curves, they also look very similar. And there was some differences in death in myocardial infarction to be taken into consideration. But all this information is important for deciding for each patient we treat right now, which is the best way to go in terms of coronary devascularization. Dr. Greg Hundley: Very nice. And so, let's circle back next to Jung-Min. What do you see as the next research study really to be performed in this sphere of investigation? Dr. Jung-Min Ahn: Thank you, Greg. So I'd like to talk about the future study, but I'd like to say something about the how to do PCI. So what is the difference between the Press trial and previous randomized trial? In the Pres trial, we used the intracoronary imaging in 72% of PCI population. This is a huge higher rate than what was used compared with the previous randomized trial. Only 10% or less than 10% PCI population used intracoronary imaging. So I think to get the comparable research to the bypass surgery, I think we have to optimize the PCR region. What is the best way shortcut to get optimizing PCR region? It could be intracoronary imaging guided PCI, could be one important way to get optimized PCR region. I think this is very important to take a message from the first trial. Dr. Greg Hundley: Well, Jung-Min, it sounds like from your description that the application of intracoronary imaging was very important in this study. Do you want to expand on that for our listeners? You know, what were maybe some subgroup analysis results of using intracoronary ultrasound? And then, how would you recommend to our listening audience that that particular technique be applied? Dr. Jung-Min Ahn: Thank you, Greg. So I mentioned that the Press trial used the intravascular ultrasound in 72% of PCI. So we analyzed the the PCI with I, without I. PCI with I showed a very comparable primary endpoint and overall mortality rate to the bypass surgery group. But PCI without I showed a significantly higher rate of primary endpoint and overall mortalities. So intravascular ultrasound guided PCI may improve the PCI outcomes and we can compare our clinical outcomes to the bypass surgery. Dr. Greg Hundley: Very nice. And Manos, do you have anything to add? Dr. Manos Brilakis: Yeah, I think the era of doing multiple huge mega trials may be tough to find these days. I think we may not have big trials comparing those two modalities, but I do agree with Junh Minh. I think the conclusion from this study as well as the previous studies is that you can choose which way to go. But if you're going to go with PCI for example, you do want to make sure that you do the best possible outcome so that you use intravascular imaging, you use physiology. We know from phase three, that use of intravascular imaging was very limited. So if you're going to go with PCI for a specific patient, the decision of course depends on the study's results and the previous studies and the patients' specific preferences. But if you're going to do PCI, you want to take your time to get the best possible result, make sure you can get as complete revascularization as possible because that will translate into better clinical outcomes as well. Dr. Greg Hundley: Very nice. Well listeners, we want to thank our main author today, Dr. Jung-Min Anh, and our own associate editor, Dr. Manos Brilakis, for bringing us this important study highlighting that in patients with multi vessel coronary artery disease, there were no significant differences between PCI and coronary artery bypass grafting in the incidence of major adverse cardiac events, the safety composite endpoint, and all cause mortality during an extended follow up period. 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. 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

    Circulation November 15, 2022 Issue

    Play Episode Listen Later Nov 14, 2022 23:43

    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

    Circulation November 8, 2022 Issue

    Play Episode Listen Later Nov 7, 2022 22:26

    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

    Circulation November 1, 2022 Issue

    Play Episode Listen Later Oct 31, 2022 23:38

    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

    Circulation October 25, 2022 Issue

    Play Episode Listen Later Oct 24, 2022 30:24

    This week, please join Circulation's Associate Editor Marc Ruel and Executive Editor James de Lemos as they summarize all of the articles found in Circulation's annual Cardiovascular Surgery-Themed Issue for 2022. Dr. James de Lemos: Hi, welcome to Circulation on the Run. Greg and Carolyn are off today. My name is James de Lemos. I'm the executive editor for Circulation and I'm delighted to be joined today by Marc Ruel, who's the editor of our themed issue on cardiac surgery and leads the development and curation of all of the cardiac surgery content in Circulation. Marc, congratulations to you, to Mike Fischbein, to the whole Circ team on another spectacular effort to pull together this issue. Glad to have you here today. Dr. Marc Ruel: Well, thank you very much, James. It's really a team effort. I want to salute and thank the vision of Circulation to really give an important component to surgical science. As you often hear me say, your surgery provides the most durable and robust solution for advanced heart disease, right? So it's a very important part of the mission of Circulation as the premier cardiovascular journal. I want to thank you and also Joe Hill, our Editor-in-Chief and obviously the entire team of Circulation as well as all staff. Augie [Rivera], who is helping us on this call as well as Nick [Murphy] and many others who have made this issue possible. Dr. James de Lemos: Well, great. Well, let's get to this. And you recognize as well Mike Fischbein, who's the Cardiac Investor surgeon at Stanford who helps to edit the themed issue and really helps us to think about basic science into surgical specialties. Let me start, Marc, with cardiac bypass surgery. We have actually three papers in this issue that cover various aspects of CABG. The first one is one that you and I really resonated with, I know, because we talked about this. It's a paper by Ono from the SYNTAX Extended Survival study titled "Impact of Patient Reported and Pre-Procedural Physical and Mental Health on 10 year Mortality after PCI or CABG." And this is a really fascinating paper, looked at obviously patients with left main or multi vessels coronary disease, but used objective measures of physical and mental function from the SF-36 score and calculated summary physical and mental component scores. And then used those scores to evaluate whether there were treatment interactions based on physical and mental performance metrics with regard to the benefit of CABG over PCI. And really fascinating, first that there was an interaction and that the magnitude of benefit of CABG over PCI for multi vessel disease was substantially greater among individuals that had higher physical performance as well as mental health performance. What did you think of this paper and data? I know you wrote a tremendous editorial to this. So this is something that you thought about as we were bringing the paper in, but also had to think about in terms of putting this paper in the context of this daily decision for patients with multi vessel disease. Dr. Marc Ruel: Thanks James. And I agree with you. I think this is a bit of a new paradigm, right, to really think of the individual patient decision. It's a form of precision medicine if you will, with regards in this case to physical functioning and mental functioning prior to something as invasive as undergoing CABG. So I want to thank you, the Circulation leadership for inviting Anne Williams who's a cardiologist and yours truly to write a tutorial on this piece because I do think you, that is really, it is something that's quite intriguing and it makes sense. I think it is intuitive. I think clinicians who send patients to CABG and see them come back and hopefully in a good state, the very vast majority of the time, do realize nevertheless that CABG is a very invasive procedure. So the patient has to be actively involved in her or his recovery. And interestingly as you pointed out, there's quite a effect modification if you will, between the benefits of CABG over PCI in the SYNTAX trial, which many will remember as having randomized either left main or three vessel disease, coronary artery disease patients to PCI versus CABG. So there was an effect modification in those patients who had better functioning, not only physical, but interestingly, even more so mental component score of the SF-36 prior to operation. These patients would derive a greater benefit from having been randomized to CABG over PCI. So I think this is obviously logical, it makes sense and the converse will be true, but it's nice to see it formalized, to my knowledge, for the first time in the context of a rigorous randomized control trial such as SYNTAX with a long-term follow up. Now obviously this, like any study, there are a few caveats. Not every single patient had their SF-36 at baseline, but roughly about 90 plus percent of patients did. And I think that is quite an important clinical lesson in terms of allocating PCI versus CBG... I've often said over the years as a division head and someone who performs this operation often to my more junior colleagues, "Don't perform bypass surgery if someone's not going to live five years." That might be a bit of a simplistic approach but the data and the conclusions from this paper would support that. It's probably not too farfetched to think as such. Dr. James de Lemos: I think that's a great point and your clinical experience is so valuable for us here. One question I have is, do you think that it would be advantageous to objectively measure these parameters or is this something that the heart team or the surgeon at the bedside can assess intuitively? Because I think that's the question, right? Is this something... It certainly fits with what we would expect intuitively, that the more complete and durable procedure works better in people that are more robust physically, mentally. But should we be measuring this preoperatively to help make that decision or should this be a intuitive decision by expert clinicians? Dr. Marc Ruel: It's a great question and I think it's one that's not yet answered. I mean, the data from the paper would suggest that it has to be a formalized physical component score and mental component score and then ready allocate according to turnstiles. But that being said, we all know that we can address those issues by an end of bed type of eyeball test, right? So I think you're absolutely right. It may be that a clinical expert may provide the same type of information. Unfortunately we don't have that from the paper but I think there will be several subsequent papers that will look at this. I think we are in the era of precision medicine and one would even think, why has this not been done before considering how invasive bypass surgery is? You guys, you cardiologists and primary care physicians all know that it takes patients six to 12 months to be recover from sternal bypass surgery. Surgeons all be, I'll say that with a blink in my eye, don't always necessarily always see that, right? And think that's more like a one to three months but the data would suggest including that from randomized controlled trials such as Feedem, that it takes six to 12 months. So it's been one of my career long quest if you will, to make bypass surgery less invasive. And I think this type of paper really provides the impetus to do so. Dr. James de Lemos: Well, thanks. Let's shift gears from a study that makes perfect sense and fits our preconceived notions to maybe one that doesn't. And this is a research letter from a group led by Steve Goldman at University of Arizona looking at long term mortality from the VA study comparing radial arteries with saphenous vein conduits in CABG. And this looked at long term mortality from this study, which included over 700 individuals that had extended follow up beyond 10 years. At one year, the cath data had not shown differences in patency in this study, I think important to interpret, but they find absolutely no difference in mortality within similar median survival of 14 to 15 years after CABG in this study. This was controversial among the editors when we discussed it, but what are your thoughts about these data and how this informs the radial artery question in CABG? Dr. Marc Ruel: Absolutely. You are so right in seeing that this was controversial because there are in fact two ways to look at this paper, right? You can drain the information that's in there or you can be a naysayer. And there's credence to both approaches, in my opinion. One could say, "Well, there was no difference at one year in terms of graph patency, so why would there be one at 14-15 years?" Well, the answer to that would be the durability of the compared conduits would be potentially different, right? One to five years is what we call the "golden age of saphenous vein grafts." And beyond that time period, one could perhaps expect that the radial artery would do better and start translating into clinical benefits. But that was not seen in this long-term analysis of the VA RCT that compared the use of a saphenous vein versus a radial artery. The other way to perhaps find why the data is discrepant versus the methodology that had been performed before showing an advantage for the radial artery, would be that this is more perhaps of a real world type of experience. It comes from VA centers. Perhaps the expertise or the level of penetrance if you will, of use of the radial artery was not the same as other centers that maybe more "academic" and more vested into using the radial. So it's possible that those could have played a difference in nullifying if you will, the results of radial artery. But I nevertheless think that it's very important data. It makes us think and it is the largest single series data available that compares the radial to saphenous vein in a randomized control setting. So one cannot ignore it, and I think it's a very important piece of information that strengthens the surgery themed dish. Dr. James de Lemos: Thank you, Marc. And then the last CABG related article that I'd like to talk about is the prospective piece by Mario Gaudino and Bruce Lytle discussing the right internal thoracic artery for bypass. Asking the question, did we get it wrong? And this is really a very interesting piece. I encourage our readers to look at. That attempts really to reconcile the strong promise of the RITA with the disappointing results from art and the higher than expected failure rates in other trials. And what the authors do here really resonates with, Marc some of your points about individualizing treatment. They point out that some of the worse than expected RITA results may reflect the artery to which the RITA has been anecimosed, simply that results when an anecimosed to non-LED targets aren't as good and potentially the experience of the operators. Their final conclusion really isn't that, the reader's not a superior conduit but that perhaps more individualization, both at the patient level but also based on physician experience, maybe what's needed to achieve the optimal selection of conduits and bypass results. What did you think of this? How did their conclusions and interpretation resonate with you? Dr. Marc Ruel: I agree with your summary James and I think you are spot on. What's interesting in addition from this frame of reference is that it unites the opinions of two key opinion leaders, i.e Mario Gaudino, who's essentially behind much of the data favoring the radial artery over the use of the saphenous vein. And Bruce Lytle, who historically was behind really proposing the use of the right internal thoracic artery and this bilateral ITA grafting if you will, and they are really coming together and putting their thoughts in a really sensible manner with regards to the points that you raised already. I would add in my own opinion, it's twofold. One, there's nothing biologically wrong with the right internal thoracic artery. So if the LITA works, the RITA should work as well from a biologic point of view. In fact, surgeons know that it's often bigger than the left internal thoracic artery and even more suitable or suited as account with. What might be wrong is the applicability of it and that question really goes in a couple of important manners. Let's remember surgery is a craft, right? And it's a bit different. It's something I like to repeat, and it's not always captured. It's not really a pure science, like for instance, giving atorvastatin 40 milligrams would be this much more variability. And if you allow me a ten second example, if you were to take one of the bronze tools from Rodin, a grape sculptures, and take it away from him, the sculptures would not be as good. But if you were to give that tool to all semi-professional sculptures around the globe, the United States or France for instance, you may not see any benefit from that tool. So again, the crafty example of surgery is something that we have to compose with all the time. So the RITA is a great conduit, but it's often not onto the LED per se. And we know that LED in an average patient, which doesn't exist, it's probably about 50% of the left heart profusion. So really the LITA has an advantage from that point of view. And when we compare studies that have used the RITA on a non LED target, there are in some cases bound to fail or at least be neutral. So I think the jury's still out but really the perspective that's denoted here, as you said, is a fascinating one coming from two key opinion leaders, each in their camp of radial versus right internal thoracic artery use. Dr. James de Lemos: Well, fabulous discussion, Marc. I really appreciate your insights. I think as cardiologists, the decision making about conduits can often be opaque, and this is really insightful. Let's switch gears and talk about valve surgery. We have two papers on valve surgery. First, an original research article by Johan Wedin from Uppsala on bicuspid aortic stenosis demonstrating adverse ventricular remodeling and impaired cardiac function prior to surgery with a heightened risk of postoperative heart failure. This is a really interesting study that looked at 271 patients that were undergoing surgical aortic valve replacement. About half with bicuspid valves and half with tricuspid aortic valves, and they did comprehensive preoperative echo-cardiography and then followed the patients for four to five years after followup. And despite the expected finding that the bicuspid patients for younger, they had a substantially worse LV echo parameters pre-op with greater LV wall fitness, greater LV mass, worse preoperative LV function. And that translated even after successful AVR into increased risks for postoperative heart failure hospitalizations when compared to individuals with tricuspid aortic valves. And so the authors conclude that at least in contemporary practice, perhaps individuals are undergoing surgery for bicuspid aortic valve stenosis relatively later in the natural history, and they might merit closer civilians and possibly earlier intervention. What did you think of these data and do they make you think about your timing of recommendation for surgery with bicuspid aortic stenosis? Dr. Marc Ruel: Absolutely, and thank you James. I think this is very much in line with the current precision medicine led trends of operating earlier on patients with aortic stenosis. I think this is another subgroup that really deserves our attention. I think there are two things at play here with regards to patients who would have a comparable degree of hemodynamic aortic stenosis, either coming from a bicuspid aortic valve phenotype versus a normal tricuspid aortic valve phenotype. And I think the two important differences are, first, often the bicuspid valves are more prone to have a mixed disease and being more calcified as well. We often see surgery, what I call these black valves, like the valve is so calcified and necrotic that it actually turns black or navy blue in color. And this is not an uncommon finding in younger patients typically than tricuspid aortic valve patients. The second thing is that we have to remember that bicuspid aortic valve disease is a lifelong illness. So these patients often go undetected for a very long time. They may be 55 years old compared to someone who's 68 and have the same degree of hemodynamic aortic stenosis and even AI. But the disease has really, in the bicuspid aortic valve patient, has probably been there for decades, sometimes even the whole life. So I think the effects on the left ventricle are destined to be worse, and also in terms of recovery after resection and after aortic valve replacement. So I think these are humbling tidbits that come from this paper that really even allow us in this era of early TAVR and now two randomized trials that have looked... One from Europe and one from Korea that have looked at asymptomatic aortic valve replacement interventions with favorable results towards early intervention. That really tell us that we should pay even closer attention to those patients with bicuspid aortic valve phenotypes. Dr. James de Lemos: Thanks, Marc. And the second valve related paper is a prospective piece by [Rebecca] Becky Hahn, Vincent Chan and David Adams, evaluating current indications for a transcatheter edged edge repair of the mitral valve for primary mitral regurgitation. I thought this was a really well done piece and one that I appreciated focus specifically on primary micro-regurgitation. The piece includes a terrific algorithm for clinicians that really helps to guide decision making through a multidisciplinary approach. They talk about the importance of specialized valve imagers, given the complexity of evaluating even the etiology of micro-regurgitation. The importance of excellence in determining the quantitation of severe MR, valve morphology and dimensions. And then really take it a step further to drive decision makings based on risk assessment of the patient. Obviously for primary MR for adequate surgical risk patients surgery is recommended, but then it walks through the decision making for which of the patients that are not surgical candidates might be optimal candidates for transcatheter techniques. How do you think this field's moving and how did this perspective change your thinking? Dr. Marc Ruel: This is such an excellent piece as you denoted. I think it really comes from three experts in the field representing different school of thoughts, if you will. One, more hybrid, more catheter based and more surgery based. And I think the jury's still out on transcatheter edge to edge repair, especially for primary marginal regurgitation. It's paradoxical as we're hoping that edge to edge repair would be primarily used in secondary MR and have great results. We now know and somewhat humbling, that it works not as great as we were hoping for secondary MR and it seems to be working pretty well where we already had a fantastic surgical therapy for it, which is essentially primary MR and Fibroelastic Deficiency type of lesions. Now, as you know, these patients do extremely well with surgery. There are several series of 800, 900, a thousand patients operated either conventionally or minimal invasively with maybe one death. Still one too much I would argue, but extremely low risks. These are the healthiest patients that a cardiac surgeon often can operate because I would argue this probably an inverse correlation with coronary artery and peripheral vascular disease in those patients. It's hard to know. There's some elements of the answer that we don't have yet. What about the very long term follow up? What about 10 years? What happens when an edge to edge repair fails and it was for primary MR in a younger patient? And I think the authors really captured those very important caveats quite elegantly and provide a very balanced view. So like you, I'm very happy with this piece. Lastly, I'll conclude by saying there's even controversy as to sub-clinical parameters with edge to edge versus surgical mitral valve pair for primary MR. What does two plus mitral regurgitation that is post-procedure, What does that mean? Is this something that's going to impact the patient at 10 years, at 20 years and perhaps churn, what was it initially, a great therapeutic solution into one that's not so desirable? So again, as I said, the jury's still out on this and I think these really captures the main element of the answer as we know them in 2022. Dr. James de Lemos: Excellent points. I think really, I love your conclusion that hopefully there will be a better transcatheter solution than this for patients that aren't surgical candidates, obviously, because it doesn't, unlike TAVR, this doesn't come close to matching the surgical option. The last couple of papers in the issue focus on putting cardiac surgery in the greater context of the patient experience and the healthcare system experience and are in the health services research phase. The first one is from multi-centered team led by Amgad Mentias at Cleveland Clinic and Ambarish Pandey at UT Southwestern. And it focuses on a new performance metric that they're calling, 90 day risk standardized home time for cardiac surgery hospitals in the US. And this group has done several studies with this new metric that basically is attempting to evaluate performance at the patient level with a very patient-centric metric of how much time they spend at home. They've published previously using data from heart failure patients and post MI patients and now are extending this to cardiac surgery and using risk adjustment of time outside the hospital in the 90 days after surgery to evaluate the variability among cardiac surgical programs. And they find that the metric correlates with mortality and readmission, that higher volume surgical centers are associated with more time spent out of the hospital. And then when they compare it more directly with approaches that are used to currently rank performance, they see that this results in some reclassification of performance categories versus the other metrics. It's early in the life of this new metric but I'm interested to see intuitively is a cardiac surgeon, how does another tool to evaluate your performance, your team's performance and your hospital's performance resonate? And does this have any intrinsic advantages to you over the other risk standardized tools that are currently being used? Certainly in the US I don't know what's happening in Canada. Dr. Marc Ruel: Great points, James and I agree, this is an impressive data set. It's almost on 1 million patients from more than 1000 centers in the US. And as you said, it is a new patient based metric. It's a bit of a patient before the outcome if you will, those PROs that are so more commonly now the object of research with regards to outcomes. I would somewhat simplistically say that there are three possible outcomes to any heart surgery, patient survives and feels better. That's number one, that's what we want to achieve for everybody. Unfortunately, there are two other outcomes that can happen. Patient survives but patient is not improved by the surgery or has a complication as a result of it and quality of life does not improve. And third, obviously the one that is the obvious, highly detrimental is that patient does not make it from the surgery. But I think really what this paper highlights is the importance of really focusing on the first one by the number of days spent at home during the first 90 days post intervention, post-surgery itself. So I think it is really a marker of how well the patient's doing. It closes the loop, if you will, with the first paper that we looked at, in an observational large data set type of way. But it again calls to, how was the patient functioning pre-op? And that data, as we know, is not available from this series. So it could be three things essentially. It could be performance and definitely it pleases the mind to think that the performance of the institution i.e, the quality of the care provided has a huge impact. But it could also be two other things. It could be the level of functioning of the patient. The ability to get back and spend many of those first 90 days at home versus not, of the patient himself or herself, depending on the various populations that are served by those institutions. And third, it could also be a little bit of a recurrent theme of mine and I apologize for that, but it could be the degree of invasiveness that's provided if you out of surgeries offered to these patients. So I think these are interesting paradigms. They are very important. Again, they're completely in line with precision medicine and I think that this performance measure, as you alluded to, is an important point because a patient who survives but doesn't go back home really is not deriving a benefit from any operation. Dr. James de Lemos: Yeah, great points. And I think this discussion really leads us into our discussion, the last paper, which is another paper that attempts to put surgery in the greater context of the population and environment in which patients come. And this is led by Aditya Sengupta and her team from Boston Children's Hospital evaluating contemporary socioeconomic and childhood opportunity disparities in congenital heart surgery. This is a really next level analysis of associations between socioeconomic status and outcomes after congenital heart disease surgery in children focusing in one high volume quaternary center in Boston. And what they did is developed a novel predictor that was a US census tract based nationally normed composite metric of contemporary childhood, what they called neighborhood opportunity. And this comprised 29 indicators across three domains. The three domains were education, health, and environment and socioeconomic domains. And they classified the patients into very low, low, moderate, high and very high neighborhood opportunity. And then they looked at evaluations across multiple outcomes. They did not see any association of neighborhood opportunity with early deaths, which I think is encouraging, but they did see that children with lower neighborhood opportunity had longer length of stay, higher healthcare costs and then significantly higher late deaths following surgery when the multiple components of long term care of these children probably have time to operationalize. I found this sobering and a complex message that excellent cardiac surgery can deliver superb outcomes across all levels of opportunity but if these issues aren't addressed, there are financial implications, but more importantly, the long term benefits of the cardiac surgical procedures aren't fully realized. Interested to hear your thoughts on this and how this might apply more broadly even to adult surgery. Dr. Marc Ruel: I agree, James and I too, really love this paper. As you say, it is sobering. It's a paper for physicians, but I would argue it's probably bedtime reading for Mr. Biden, any other country leaders as well. Whether it's Mr. Macron or Mr. Trudeau. Definitely something that is shows that what happens after the hospital stay, even in something as complex as congenital heart surgery, performed at Boston children, obviously a great institution. But what is shown here is that the institution with its top quality outcomes as we know them to be, is a fantastic societal and outcome equalizer, if you will. But once that passage through the tertiary or coronary institution has occurred, then reality sets in. And the childhood opportunity index that the authors had previously published in JAMA proves to be, again, a very important predictor of how these kids do later on. So this refers really to the societal contract that we're all part of as physicians. And we obviously, a big part of our mission is to improve the outcomes in hospital, but also beyond it. And I think this paper illustrates this very nicely as you so eloquently summarized. Dr. James de Lemos: Well, thanks. And I'll just, before I hand it over to you to conclude and wrap up, just compliment you and Mike and the entire team, as well as the authors who have submitted not just these but so many other superb papers covering the full spectrum of surgical sciences Circulation. I'm proud for us to have the opportunity to share these terrific papers with our readers and with researchers. And congratulations again to you for pulling this together. Dr. Marc Ruel: Well, you're very kind and thank you, James. To you and Joe, Darren and our and entire editorial leadership for the important place given to surgery within Circulation. It's something that I believe is important and resonates with surgeons but also non-surgeons who are part of the greater cardiovascular community. So it's tremendously important and we're very thankful for that opportunity. Dr. James de Lemos: Well, I'd like to thank all our listeners for joining us today and remind you to tune in next week when Greg and Carolyn will be back for their regularly scheduled podcast. 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

    Circulation October 18, 2022 Issue

    Play Episode Listen Later Oct 17, 2022 22:48

    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