Podcasts about copyright american heart association

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: Hundley, Associate Editor from the Pauley Heart Center in Richmond, Virginia at VCU Health. Well Carolyn, our featured article this week addresses the age at which to initiate clinical screening of relatives for hypertrophic cardiomyopathy. Our guidelines suggest screening of relatives from age ten and onwards but data are lacking to substantiate this suggestion. I look forward to the authors' discussion of their findings regarding initiation of screening in children. For now though, do you have an article that you'd like to share? Dr Carolyn Lam:                You bet, Greg. So, the first paper I chose really demonstrates that patients inducible pluripotent stem cells or IPSC cardio derived myocytes can be used as a disease modeling platform to delineate the functional mechanisms that underlie cardiac hypertrophy and in this particular case they looked at Noonan Syndrome and showed that how these techniques can be subsequently used to identify novel molecular and genetic therapeutic targets. So, Greg, here's your quiz. The genetics of Noonan Syndrome. Dr Greg Hundley:             I remember it was on our board exam. Dr Carolyn Lam:                Let me tell you about it. So more than 90% of patients with Noonan Syndrome have a mutation in the hinge region CR2 domain of Raf-1 and they exhibit severe hypertrophic cardiomyopathy for which there is no treatment. Authors, Dr Jaffrey from Cornell University and Dr Kontaridis from Masonic Medical Research Institute in Utica in New York and their colleagues used Noonan Syndrome Raf-1 patient and CRISPR corrected IPSC cardiomyocytes to recapitulate the Noonan Syndrome cardiac phenotype.                                                 These Noonan Syndrome IPSC derived cardiomyocytes exhibited the same hypertrophy and myofibrillar disarray that's really observed in Noonan Syndrome patient hearts, so mechanistically the authors showed that activation of mitogen-activated protein kinase or mech-1 or -2, but not the extracellular regulated kinase, which is ERK1 or 2 triggered abnormal cardiomyocytes structure and conversely ERK5 mediated increased cell size in these Noonan Syndrome mutant IPSC derived cardiomyocytes.                                                 RNA sequencing further identified genes dysregulated in the Noonan Syndrome cardiomyocytes that may underlie hypertrophic cardiomyopathy downstream if the mech-1 or -2 and ERK5 genes. Dr Greg Hundley:             So, Carolyn, that's a lot of genetic information, so what can I take home as I think about this further and what may come down the line as we manage patients with Noonan Syndrome? Dr Carolyn Lam:                Thanks, Greg. The real take home message is that these pathways could serve as novel therapeutic targets to treat hypertrophic cardiomyopathy in patients with Noonan Syndrome and Raf-1 mutations. Overall, the elucidation of rare disease mechanism of hypertrophic cardiomyopathy may further unravel and reveal causes of other more common idiopathic congenital disorders and hypertrophic diseases. Dr Greg Hundley:             Oh, very good. Well, I'm going to switch gears and talk a little bit about infective endocarditis prophylaxis and this article comes from Pallavi Garg at the London Health Scientist Center. Carolyn, as you may recall, given the lack of proven efficacy and concerns about the perceived risks of antibiotic prophylaxis like development of antibiotic resistance, the American Heart Association in 2007 and the European Society of Cardiology in 2009 published revised guidelines recommending cessation of antibiotic prophylaxis prior to dental procedures for patients at moderate risk of infective endocarditis while continuing the practice in high risk patients. This Canadian study was conducted from 2002 to 2014 among all adults and those at high and moderate risk for infective endocarditis and they were stratified by age. Prescriptions for antibiotic prophylaxis were obtained from the Ontario Drug Benefit Database for adults 65 and older and outcomes regarding antibiotic prophylaxis prescription rates and the incidents of infective endocarditis related hospitalization were assessed. Dr Carolyn Lam:                 Ooh, interesting. What did they find? Dr Greg Hundley:             The authors found a sustained reduction in antibiotic prophylaxis prescriptions among individuals at moderate risk for infective endocarditis that coincided with the change in guidelines. In contrast, while there was a decreasing trend in antibiotic prophylaxis among individuals at high risk of infective endocarditis and a minimal drop following the guidelines released, the overall rates of prophylaxis prescribing in this group continued to climb since early 2007, and collectively, these findings suggest that appropriate uptake of the revised AHA guidelines occurred.                                                 Furthermore, over the thirteen-year study period, the authors identified an increase in hospitalizations for new episodes of endocarditis approximately three years after the AHA guidelines were revised. This timeline along with the rise of endocarditis incidents in both the high and moderate risk groups suggests that this observed increase in endocarditis is likely unrelated to the change in the prescribing practice of antibiotic prophylaxis. This conclusion is further supported by the overall decrease in endocarditis cases attributable to streptococcal infections over time, a finding contrary to what might be expected as a result of the reduction in antibiotic prophylaxis. Dr Carolyn Lam:                Oh, very interesting, Greg. At first a little bit scary and then after when you described it more, it does seem a little bit more reassuring. Very interesting. Well, thank you. My next paper deals with functional tricuspid regurgitation, which as you know is really common in heart failure with reduced ejection fraction or HFrEF and mostly consequent to pulmonary hypertension. However, what is the access mortality associate with functional tricuspid regurgitation in HFrEF? Well, this paper from Dr Maurice Serrano from Mayo Clinic and colleagues looked at all Mayo Clinic patients from 2003 to 2011 diagnosed with heart failure stage B and C and an ejection fraction less than 50% who had functional tricuspid regurgitation grading and systolic pulmonary artery pressure measured by Doppler echocardiography.                                                 Now among more than 13,000 patients meeting these inclusion criteria, functional tricuspid regurgitation was detected in 88%. Functional tricuspid regurgitation was independently associated with more dyspnea, more impaired kidney function, and lower cardiac output. For the long term outcomes, the higher the degree of functional tricuspid regurgitation compared with a group with trivial tricuspid regurgitation was independently associated with a higher mortality hazard. The five year survival was substantially lower with increasing severity of tricuspid regurgitation so it was 68% on average for trivial functional tricuspid regurgitation versus 34% for severe functional tricuspid regurgitation.                                                 Importantly, this access mortality observed with moderate or severe functional tricuspid regurgitation was independent of pulmonary hypertension and any other clinical characteristics. Dr Greg Hundley:             Hmm, interesting but Carolyn, wouldn't we expect this? Dr Carolyn Lam:                You know what, you may expect it, but this is really the largest series, I think, that has shown this and shown this in the systematic way that functional tricuspid regurgitation in and of itself may play an important pathophysiologic role and thus, may represent a potential therapeutic target in HFrEF. In other words, the present study really advocates for a trial to test treating functional tricuspid regurgitation in patients with HFrEF. Dr Greg Hundley:             Oh wow, you really put that in great perspective, Carolyn. Well, your reward is   going to be a quiz. Dr Carolyn Lam:                 Oh my gosh, Greg. Dr Greg Hundley:             We're going to talk about ... Dr Carolyn Lam:                 What now? Dr Greg Hundley:             Caveolin-1, an atherogenesis and nitric oxide and this is from Professor Carlos Fernandez Hernando at the Yale University School of Medicine. Okay, multiple choice. What are caveolae? Now I'm going to give you some choices, you get to pick A. Are they crypts within the walls of vessels. B. Crypts within the membranes of endothelial cells. Or C. Crypts within the border zones of infarcts. Dr Carolyn Lam:                Wait a minute, Greg. I'm not even sure we're pronouncing it the same. You're asking about caveolae like ... Potato potata. They're invaginations of cell membranes, that's all I know. Dr Greg Hundley:             Oh wow, fantastic. This study focused on the effect of Caveolin-1, a protein integral to the formation of caveolae. The investigators found in a series of mouse experiments that A. The athero-protection observed in mice lacking Caveolin-1 is independent of endothelial nitric oxide synthase activation and nitric oxide production. B. Endothelial Caveolin-1 controls lipoprotein infiltration in vascular inflammation in early stage atherosclerotic lesion. C. Endothelial Caveolin-1 promotes pro-atherogenic matrix deposition leading to endothelial cell activation in atheroprone regions of the aorta and finally, D. Atheroprone regions of the aorta are characterized by increased intracellular and basolateral caveolae distribution in endothelial cells compared to athero-resistant areas. Dr Carolyn Lam:                Wow, I like the way you broke that down into four points, but could you summarize what it means clinically? Dr Greg Hundley:             Yeah, so I think if you had to summarize all of this in a sentence, perhaps the suppression of Caveolin-1 expression in endothelial cells might prevent the progression and promote the regression of atherosclerosis so in the future perhaps an interesting target to treat atherosclerosis. Well, now Carolyn, I guess we should proceed to that talk with our featured discussion. Dr Carolyn Lam:                 Absolutely. Thanks, Greg.                                                 Hypertrophic cardiomyopathy is an inheritable myocardial disease with age-related penetrance. Current guidelines recommend that clinical screening of relatives start from the age of ten years onwards by the European Society of Cardiology and twelve years onwards by the American College of Cardiology or American Heart Association. There are of course caveats for earlier screening but the clinical value of this approach has really not been systematically evaluated. That is until today's feature paper and we are so pleased to be here discussing it. This is Greg Hundley and Carolyn Lam and we're your co-hosts for Circulation on the Run. So happy to welcome Dr Juan Pablo Kaski who's the corresponding author of today's feature paper from Great Ormand Street Hospital in London and we also have Dr Gerald Greil, Associate Editor from UT Southwestern.                                                 Welcome, everyone. Juan, if you don't mind, could you start by summarizing this very important study of yours? Dr Juan Pablo Kaski:        Thank you very much. Hypertrophic cardiomyopathy is a genetic muscle condition that is characterized by hypertrophy and is most commonly inherited as a dominant trait. Previous studies have suggested that in familial disease at least ventricular hypertrophy doesn't usually present until adolescence and this has led to the current guidelines which do not recommend routine screening of children below the age of twelve according to the American guidelines below the age of ten and the European guidelines for hypertrophy cardiomyopathy but own clinical experience was different and suggested that perhaps sarcomeric disease and familial disease could present in younger children, so what we aimed to do with this study was to assess the validity of this approach and tried to assess the yield of clinical screening in children from families of hypertrophic cardiomyopathy. Dr Juan Pablo Kaski:        We took our collective experience in our institution over a period of many years and recruited just on the 1,200 consecutive children all aged less than eighteen years at the time of initial assessment coming from just under 600 families and these were children who were referred for clinical screenings because a first degree relative had been diagnosed with hypertrophic cardiomyopathy. What we found was that in 5% of these children and in fact, in 8% of the families that we screened, we were able to pick up early phenotypic features of hypertrophic cardiomyopathy. In 72% of patients, we made a diagnosis before the age of twelve, so before current clinical screening guidelines we'd recommend and importantly, a third of these patients during follow up had a change in their management as a result of the diagnosis. Their medication was commenced, they underwent procedures or implantations of defibrillators. Dr Greg Hundley:             Juan, this is Greg Hundley and I was wondering when did the participants that were enrolled experience events? Did those that were say under fourteen or even under twelve, did they experience events relative to those that were a little older? Dr Juan Pablo Kaski:        The events that our participants experienced were relatively few. Many of these occurred during the childhood age but some occurred once the children had transitioned into the adult age. We did look to see whether there was any difference in terms of early diagnosis and subsequent events, but we didn't find anything, we didn't identify two separate populations in that respect. Dr Greg Hundley:             And then did you perform genetic analyses? I know you described phenotypic characterization of the patient population but how about genetically? What results did you find there? Dr Juan Pablo Kaski:        The main aim of the study really was to determine a yield of clinical screenings, so this is a reflection of a real-world practice where genetic testing may not necessarily be routinely available. Having said that, we did have genetic data in a third of our families and in fact, in maybe 70% of those children who made clinical diagnosis of hypertrophic cardiomyopathy was made and what we find in those individuals who have undergone genetic testing is that the vast majority of those had mutations in sarcomeric protein genes and pathogenic or likely pathogenic variants in sarcomeric genes in just under 70% and these were well characterized mutations that are very similar to those that are seen in adolescence or adult onset hypertrophic cardiomyopathy.                                                 I think what was interesting about these genetic results is that we seem to have identified a population of early onset sarcomeric disease that genetically appears to be indistinguishable from a sort of later onset adult disease but with the clinical presentation and natural history curve shifted somewhat to the left. Dr Greg Hundley:             Gerald, just switching over, can you tell us some of your thoughts about how the results of this study will impact clinical practice, both in the European countries as well as U.S.? Dr Gerald Greil:                 I mean, I was obviously delighted to see the study being submitted to circulation because there's a very important message particularly for pediatric cardiologists which is potentially influencing the guidelines and Dr Kaski may comment on this as well as the next step meaning that it seems like screening patients older than ten or twelve years and once again, there's a slight discrepancy between the European and U.S. guidelines, seems to be ... Can be questioned and potentially we should screen these patients earlier.                                                 Another amplification of this study is that we should think about how much genetic screening can be an essential tool in our methods in looking at these patients and I want to point out that because of these discrepancies we also initiated an editorial letter for this publication done by Dr Ommen and by Dr Mital kind of pointing out there needs a lot of work to be done maybe even including rewriting the current guidelines.                                                 There's another paper that came out recently in European Society Cardiology, the European Heart Journal about a similar topic so it's something which is very, very heavily discussed in our community. We think how we are looking at these patients and how we're following them up. Dr Greg Hundley:             What would you suggest are next steps for the world community in this space in regards to modifying those guidelines? Dr Gerald Greil:                 I think there's now enough literature around which suggests that we should look at these patients earlier and screen them earlier on both sides in European, in the U.S., in the Asian world, and ideally these two groups should sit together and write combined guidelines. It's still interesting that the European and U.S. guidelines are slightly different in that we're talking about a similar group of patients, so I'm very, very delighted to see that this is coming up in the national literature as a new topic and I think everything is open now to rethink this topic and rewrite these guidelines. Dr Greg Hundley:             Do you think prospective studies would be necessary because I believe, and Dr Kaski please weigh in here, this was a retrospective review, and do you think there could have been triggering circumstances that prompted early screening? I mean, would a next step be some sort of prospective registry? Dr Gerald Greil:                 I mean definitely that's the next step. I think we have enough data material around once again to rethink the strategy which age these patients should be looked at. A prospective registry and Dr Kaski can probably comment on it better than I can, I think that something which is a logical next step and there may be even something being on the way to make this happen. Dr Juan Pablo Kaski:        I agree. I think further validation and confirmation of these data from prospective studies would be extremely helpful. I think one of the things that we need to bear in mind is the potential cost implications of expending screening to ever increasing populations and so perhaps an additional further step would be to try to refine the screening tools so that we are able to identify clinical by a chemical of those individuals who are more likely to present in childhood and perhaps set a target screening towards that population.                                                 I can just go back to one of your sort of previous points also about a potential bias and it is true that these patients were referred for clinical screening at a time when clinical recommendations do not suggest that this is necessary and although we didn't specifically in this cohort look at those that would have fulfilled current early screening criteria, the vast majority of the patients were asymptomatic at the time that they were referred. We also looked to see whether there was any link between those individuals who had a family history of early onset disease and an early diagnosis, and that was the only factor that came up as potentially significant so perhaps the current guidelines that do recommend considering earlier screenings if there's a family history of childhood disease are still applicable. Dr Carolyn Lam:                That was just an amazing interview, by the way. I've learned so much and thank you so much for publishing this very important paper with us.                                                 You've been listening to Circulation on the Run. Don't forget to tune in again next week. This program is Copyright American Heart Association 2019.  

Dr Carolyn Lam:                Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. I'm Dr Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr Greg Hundley:             And I'm Greg Hundley, Associate Editor of Circulation from the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr Carolyn Lam:                Are NOACs, or non-vitamin K antagonist oral anticoagulants, safe and efficacious in patients with extremely high or very low body weight? Very interesting paper and discussion coming right up. Greg, I hear that you've got a couple of papers you'd like to highlight first. Dr Greg Hundley:             You bet, Carolyn. My two papers today both focus on ventricular dysrhythmia. The first one, from Yuki Komatsu from Tsukuba, Japan, researches the efficacy of catheter ablation of refractory ventricular fibrillation storm after myocardial infarction. VF storm attributed to focally triggered VF after MI is recognized as a distinctive, lethal, arrhythmogenic syndrome that differs from scar mediated monomorphic VT.                                                 This study investigated the acute and long-term outcomes of catheter ablation for the treatment of last resort in a large series of consecutive patients with post-MI VF storm refractory to medical therapies. In the study, investigators enrolled 110 patients averaging about sixty-five years in age. Ninety-two were men, and their average ejection fraction was approximately 31%. VF storm occurred in the acute phase of MI, about four and a half days after MI-onset, during the index hospitalization in about 39% of the patients. It was sub-acute (that is greater than 1 week later) in 44% of patients. It was remote (greater than 6 months later) in 17% of patients. And the focal triggers were found to originate from the scar border zone in 80% of the individuals. Dr Carolyn Lam:                And what did the study show? Dr Greg Hundley:             So Carolyn, during in hospital stay after ablation, VF storm subsided in 84% of patients and overall, 27% of in-hospital deaths occurred. The duration from the VF occurrence to the ablation procedure was associated with in-hospital mortality, with a P-value of 0.008. During follow-up after discharge from the hospital, only one patient developed recurrent VF storm. Of note though, 36% of the patients died, with a median survival of 2.2 years. And the long-term mortality was associated with a low EF (less than 30%), New York Heart Association class greater than 3 Heart Failure, a history of atrial fibrillation or chronic kidney disease.                                                 So in summary Carolyn, the results of this study show that in patients with MI presenting with focally-triggered VF storm, catheter ablation of the culprit triggers is life-saving and appears to be associated with short and long-term freedom from recurrent VF storm. The overall mortality for these patients is associated with the severity of their underlying cardiovascular disease, and those associated co-morbidities.                                                 Now my next paper is from one of our associate editors, Sami Viskin from Tel Aviv University. He's looking at a new form of polymorphic VT. Now as we think about polymorphic VT, I always think about the long QT interval syndromes associated with Torsades de Pointes. We have specific management strategies for those long QT syndromes, but Carolyn, there's a second category of polymorphic VT that's not related to QT prolongation. This second category involves patients without structural heart disease, who have genetic disorders like Brugada or patients that may have experienced hypothermia. There is also a third category of individuals with structural heart disease, during acute ST elevation MI.                                                 What Sami has discovered is there's now a fourth category of non-QT prolongation, which includes those with coronary artery disease but without evidence of ischemia. Dr Carolyn Lam:                So how did they show or find this fourth category? Dr Greg Hundley:             Well, this is a longitudinal cohort that he identified, and they basically followed forty-three individuals who developed polymorphic VT within days of an otherwise uncomplicated MI or coronary revascularization procedure. The in-hospital mortality was 17% with these patients with arrhythmic storm and the patients were treated with quinidine invariably survived to hospital discharge, just like the other categories of non-QT prolongation polymorphic VT.                                                 During long term follow-up of five and a half years, 16% of patients discharged without quinidine developed recurrent polymorphic VT and there were no recurrent arrhythmias in those individuals that were receiving quinidine therapy long term.                                                 So Carolyn, although quinidine therapy is usually considered contraindicated in patients with organic heart disease who develop ventricular arrhythmias, this therapy may be life-saving for patients with coronary disease developed arrhythmic storms due to polymorphic VT. Polymorphic VT storms may be a transient phenomenon. It's unclear for how long quinidine should be continued in these responsive patients. Dr Carolyn Lam:                Wow, neat! Well, for my two papers I'm going to start off with a basic paper and, in fact, a quiz for you this time, Greg! So, what do cilia have to do with the heart? All right, you get to ask me, do you remember what cilia are? Dr Greg Hundley:             Aren't cilia on prokaryotes? I mean, I think of bacteria. Dr Carolyn Lam:                All right, let me set us straight. The primary cilium is a cellular organelle and it's formed by a protrusion of the plasma membrane that functions as a signaling platform in eukaryotic cells and is found in many cells including neurons, pre-adipocytes and kidney tubular cells, where they have been reported to be involved in a variety of cellular functions such as proliferation, differentiation, cell cycle regulation as well as mechano-chemical sensing of diverse stimuli.                                                 Now, the importance of these cilia is highlighted by the role in several diseases, known as ciliopathies. Polycystic kidney disease is one such disorder with, by the way, numerous cardiovascular manifestations. Whereas ciliated cells have been described in the developing heart, a role for primary cilia in the adult heart has not been reported. It was therefore the aim of these authors and those co-corresponding authors Dr Hill from UT Southwestern and Dr Lavandero from University of Chile, who aimed to identify cells in the adult heart harboring a primary cilium and to determine whether these primary cilia play a role in disease-related remodeling. Dr Greg Hundley:             Carolyn, this is so interesting. I had no idea about these cilia. So what did they find? Dr Carolyn Lam:                So, in a series of elegant experiments, these authors identified for the first-time primary cilia in mouse, rats, and human hearts, specifically and exclusively in cardiac fibroblasts. Now these ciliated fibroblasts were enriched in areas of myocardial injury. Transforming Growth Factor beta-1 signaling and SMAD3 activation were impaired in fibroblasts that were depleted of the primary cilium. Extra cellular matrix protein levels and contractile function were also impaired. And in vivo depletion of PC1 inactivated fibroblasts after myocardial infarction impaired the remodeling response. Dr Greg Hundley:             So how do we use this clinically, and what does it mean for us? Dr Carolyn Lam:                These findings point to a pivotal role of cilia and PC1 in disease related pathological cardiac remodeling and suggest that some cardiovascular manifestations of autosomal dominant polycystic kidney disease, for example, derive directly from myocardium autonomous abnormalities. The findings also uncover novel fibrosis regulators and raise the prospect that this pathway may emerge as a target with therapeutic relevance. Dr Greg Hundley:             Wow, very interesting! Dr Carolyn Lam:                Thanks! And the next paper is also very interesting, in dilated cardiomyopathy and providing insights in how specific viral function may be involved in the development of dilated cardiomyopathy. Looking at the Group B enteroviruses, which are a common cause of acute myocarditis and can be a precursor of chronic myocarditis and therefore dilated cardiomyopathy leading to heart transplantation. In fact, enterovirus-induced dilated cardiomyopathy represents a third of idiopathic dilated cardiomyopathy cases.                                                 So these authors, led by corresponding author Dr Andreoletti from University of Reims, Champagne-Ardenne and Dr Semler from University of California, performed deep sequencing of viral RNA from cardiac tissue from patients with enterovirus related end stage dilated cardiomyopathy and then trans-factored viral RNA clones, mimicking the viral genomes found in patient tissues into primary human cardiac cells to assess their replication activities and impact on cardiomyocyte function.                                                 They found that the major persistent viral forms are composed of B-type enteroviruses harboring 5' terminal deletion in their genomic RNAs. These viruses alone, or associated with full length populations of helper RNAs, could impair cardiomyocyte function by viral enterovirus proteinase 2A activities in these enterovirus-related dilated cardiomyopathy cases. Dr Greg Hundley:             Very interesting, Carolyn. So what are the clinical implications of this viral infection of the heart? Dr Carolyn Lam:                Well, the findings seem to imply that it would be important for us to develop specific inhibitors of enterovirus proteinase 2A activity that might prevent viral replication and inhibit the shut-off of host cell translation as well as the disruption of dystrophin.                                                 Furthermore, in early diagnosed enterovirus induced dilated cardiomyopathy, the use of such protease inhibitors could potentially decrease and stop the chronic pathological process of dilated cardiomyopathy and therefore reduce the need for heart transplantation in this end-stage. Very interesting, but requires more work.                                                 So, that wraps up our summaries Greg. Shall we move to our feature discussion? Dr Greg Hundley:             Absolutely. Dr Greg Hundley:             Today we have Renato Lopes from Duke University in Durham, North Carolina and Brian Olshansky, Professor Emeritus from Iowa now in clinical practice in Waterloo and Mason City, Iowa. We're going to talk about our non-vitamin K oral antagonists, or NOACs, safe and efficacious in patients in extremely high (greater than 120 kg) or extremely low (less than 60kg) of body weight.                                                 Renato, welcome to our podcast in Circulation on the Run. Can you give us a little overview of your study, why you performed it and what results did you experience? Dr Renato Lopes:              The idea behind this study was to provide more data into the use of NOACs in these extreme body weight patients, where we don't have a lot of information. Some guidelines actually caution against the use of NOACs in patients with extreme body weight because of the lack of data.                                                 We had the opportunity to look at the Aristotle database, which was a large, randomized trial comparing apixaban versus warfarin for patients with atrial fibrillation, over 18 000 patients. We took advantage of this database to try to look at the extreme body weight and how those patients at weight more than 120 kg, more than 140 kg and less than 60 kg, performed in terms of the treatment effect of apixaban versus warfarin. This was the rational, to try to provide more data so people could gain additional confidence in using apixaban in clinical practice in those extreme body weight patients.                                                 What we showed was, in general the treatment effect of apixaban versus warfarin for the efficacy outcomes CHOKE, systemic embolism and all cause death and myocardial infarction was very consistent across the weight spectrum and preserved. Apixaban was superior to warfarin and this was consistent regardless of the weight category. For the low body weight patients less than 60 kg, we also found that apixaban results in terms if efficacy was preserved.                                                 So, going out to the bleeding and safety endpoints, apixaban was safer than warfarin across different spectrums of weight. Surprisingly, in patients less than 60 kg we saw an even greater relative risk reduction in bleeding, in patients treated with apixaban compared to warfarin. The main message was for efficacy, apixaban was better than warfarin - the same results as the Aristotle main trial. For bleeding and safety endpoints, we also saw the same results and consistent results with apixaban- in particular with patients below 60 kg, which is always a concern that people might have in clinical practice. It seems that apixaban was even safer with an even greater treatment effect. Dr Greg Hundley:             Very nice. Can you tell us a little bit about some of the sites where you enrolled patients and did you identify any variation in age, sex or region specific factors? Were there any differences in your findings related to race? Dr Renato Lopes:              That is a very interesting question because we know that these variables play an important role in body weight. We enrolled patients from thirty-nine countries in Aristotle, in over a thousand sites all over the world. Interestingly, I can tell you that the heaviest weight we had in our study was 205 kg, a patient from the United States. The lightest weight that we had was 39 kg, from the Philippines. You lose trading the variation that regions of the world can play out and how patients can perform. We haven't seen any major difference in these analogies. There were prior analogies that look at different BMIs, and we know that the treatment effect might be attenuated depending on race and sex. In this analogy, we did not find any significant difference according to race, region of the world or even sex. Dr Greg Hundley:             Just getting back to your body weight measurement, you mentioned percentage of individuals were above 120 kg and briefly mentioned some were above 140 kg. What percentage of your study cohort was that extra-large size, above 140 kg? Do you think more work needs to be done in that area or do you think the results were sufficient for that very heavy body weight? Dr Renato Lopes:              This is a very important question. If we look at the breakdown, we had about 11% of the entire trial in the low spectrum of weight, less than 60 kg in weight - almost 2000 patients. A good number of patients. In extreme weight more than 120, we have about 980 patients. That was 5.5% of the overall trial. When you look at greater than 140 kg, we had 258 patients, 1.4% of the overall trial population and about 25% of this category greater than 120.                                                 I think as we start getting greater than 140 kg, we had 258 patients. It is not a large number of patients. It is some information and it is good to have some data on these patients. Before that, we had no data on apixaban in this level of weight. What we are seeing is that above 140 kg, the death rate are very low. There is a trend to better bleeding endpoints and better bleeding profile with apixaban, similar to what we have seen in the entire spectrum of weight when we look at weight as a continuous variable. We also saw that trend in patients greater than 140 kg for bleeding. This is reassuring. I don't think we can say it is definitive, it is only 260 patients that we are talking about.                                                 It is reassuring that we now have data in patients more than 140 and up to 205 kg, and we didn't seem to see any major concern or any difference in the curves in terms of the direction of efficacy and safety of apixaban. For the majority of patients it is reassuring and gives us extra confidence that the dose we use in clinical practice five milligrams twice daily should also work in those heavy weight and the heaviest body weight patients. Dr Greg Hundley:             Very good. Brian you've done an excellent editorial and I wonder if you could help us put this study in perspective with what we know about NOACs and managing patients with atrial fibrillation? Dr Brian Olshansky:         It really is a fascinating study. Obesity is as growing problem for us here in the mid-west and probably throughout the world. It effects a variety of things including drug pharmakinetics, volume of distribution, drug clearance etc. So knowing how NOACs work at the extremes of body weight, either the massively obese or the vanishingly frail, it becomes important to understand the safety and efficacy of the use of NOACs in these individuals. There are guidelines that caution us against use of NOACs at extremes of body weight, particularly those patients who are over the 120 kg mark. The one point I would like to make is, at least here in the mid-west, 120 kg is becoming almost the norm. We are having people that are becomingly massively obese and this is really the question then in my mind, is what to do with those patients who are over 140 kg or even way more than that. This gets to points that I would like to make about some the issues we need to consider about this study and where we are with our understanding about the use of NOACs in the extremes of body weight.                                                 One thing to keep in mind is, in this analysis, this was a retrospective group analysis. That is one important point. We don't have prospective data that look at an entire large population, a very frail, a very low body weight population.                                                 Another issue is that weight is not a static measure. We only have assessment at the baseline. Variability in weight or body mass index may be important in terms of its relationship to the development of atrial fibrillation and sequelae. The other issue here to consider is that there are comorbidities that are associated with those who are at the extremes of body weight and there was a significant variation in this study in age composition, sex dominance, the region of enrollment, the presence of comorbidities between the different weight groups that could contribute to results we have seen. Those with low body weight had more comorbidities and a higher mean CHADSVASC score, and had the biggest difference between apixaban and warfarin.                                                 We have quite a bit to learn about how to understand these data, and when we consider the individuals who are over 140 kg, indeed there are concerns about the volume of distribution of a NOAC and its efficacy. We would like to rely on this data. The problem is that the number of individuals that are a part of this retrospective analysis at the very high body weight and very low body weights was a rather small number and so to project from that number, what we should do with all of our patients becomes somewhat of a concern.                                                 Although these are interesting and provocative data, what we really need is to have some well-designed large prospective randomized controlled trials that specifically address those individuals at the extremes of body weight because this is becoming more and more of a problem as time goes on. We are seeing more individuals that are at the extremes of body weight. While I have not specifically noticed a difference in my own clinical practice, what we need is a better understanding about the dosing of and potential risks and benefits of the NOACs for the extremes of body weight. Dr Greg Hundley:             On behalf of Carolyn and myself, we really appreciate you listening. Have a great week. We look forward to seeing you next week. Dr Carolyn Lam                  This program is Copyright American Heart Association 2019.  

Dr Carolyn Lam:                Welcome to Circulation On The Run, your weekly podcast summary and backstage pass to the journal and it's editors. I'm Dr Caroline Lam, associate editor from the National Heart Center and Duke National University of Singapore. Greg Hundley:                   And I'm Greg Hundley, Professor at the Pauley Heart Center of Virginia Commonwealth University Health Sciences in Richmond, Virginia. Dr Carolyn Lam:                In case you guys missed us last week, this is how our new podcast is gonna work. Greg and I are going to invite you for coffee with us, almost with a journal in hand, and we're gonna chat about the week's issue, highlighting two original papers each, that we thought were awesome. And don't you worry, the feature discussion is still there, authors will join us for a feature discussion right after our coffee.                                                 And for this week, the feature paper speaks about the MOMENTUM 3 trial, and talks about the important analysis of stroke outcomes in this trial. But before that, I think Greg, you've got a couple of papers don't you? Greg Hundley:                   Absolutely Carolyn. So the whole issue, I think we're gonna pick out several stroke papers, really a stroke theme. The first paper is Ankit Maheshwari. He looked at the utility of P-wave morphology on the 12-lead electrocardiogram, to help predict ischemic stroke in patients with atrial fibrillation.                                                 Now, how did he do this? Basically, they looked at a large cohort of individuals from the ARIC study, and these were patients that developed atrial fibrillation. And electrocardiograms had been recorded prior to their Afib episode.                                                 So, what were they looking for in P-wave morphology? Well, they were looking for changes in Lead three. They were looking for changes in V1. They were also looking for extension of that P-wave. So a prolonged duration. And what they observed, is that that abnormal P-wave, could forecast abnormal atrial remodeling, that might be an indicator of future stroke. Dr Carolyn Lam:                Huh, interesting. But is it really reproducible? Did they validate it somehow? Greg Hundley:                   Yeah, so that's great Carolyn. You know, in papers like this, you like to take a finding in one large cohort, but then you've got to reproduce it. So they went to the MESA Study. Remember now, Mesa are individuals without cardiovascular disease. ARIC are patients with cardiovascular disease. And the finding was reproducible in MESA. Also, what the authors did, is they looked at the relevance of this EKG finding to our existing CHADS-VASc2 scoring system.                                                 And what was really smart by these investigators, is that if you added the information from the abnormal P-wave morphology to the CHADS-VASc2 score, you could forecast stroke. Now you say, well CHADS-VASc2 is already pretty reliable, but what about those patients that have a CHADS-VASc score of one right? We're always kind of wondering, do we anticoagulate them? Do we give them aspirin, et cetera. Well if the P-wave morphology was abnormal and they were at higher risk for stroke, that could sway you as a clinician, to go ahead and prescribe anticoagulation for that group of patients.                                                 And something very simple, just from the 12-lead EKG before the patients went into atrial fibrillation. You've got a paper that also is sort of focusing on stroke. You want to tell us about that? Dr Carolyn Lam:                Yeah, one big data to another big data series. This time, it's Get With The Guidelines Stroke series, and this paper is from Dr Menon from University of Calgary in Canada. Where they described the door to treatment times for endovascular therapy in acute stroke. What is that? Well that's a time interval from when the patient arrives in the emergency department or the door, to the first pass of the treatment initiation and endovascular therapy. And basically they found that the median door to first pass time was 130 minutes. Only 3% of patients achieved a door to first pass time of less than 60 minutes.                                                 In multivariable analyses, older age arrival during nonregular hours and a history of diabetes, were all associated with the longer door to first pass time. And finally, among hospitals with an annual endovascular therapy case volume of 40 or less, every five unit increase in that volume was associated with a 3% reduction in this door to first pass time. Greg Hundley:                   It sounds like that could be really useful information for stroke centers, you know, that are managing these patients acutely. How do you think these results are going to impact that Carolyn? Dr Carolyn Lam:                Great question. So first thing is, I think it provides some benchmark times for this in hospital workflow, and it obviously shows areas of improvement. For example, improving workflow during nonregular hours, or increasing the experience of a center, and basically emphasizes the point that efforts on streamlining workflow and saving time, need to continue so that the full potential of endovascular therapy is realized. Greg Hundley:                   Oh wow, that's outstanding. I'm gonna transition sort of to a basic science paper, also trying to help manage patients with stroke. This one is looking at the safety of all of the dehydrogenased right stem cells. Well, what the world is that. In animals, what has been shown previously, is this particular cells type, that's harvested from your bone marrow, can be infused into the carotid artery, and those animals experience smaller neurologic deficits after stroke. And so with that encouraging result in animals, these investigators sought to test the efficacy of this type of therapy, well not really the efficacy, but the safety of this type of approach in those patients that have sustained actually quite a large stroke.                                                 You had to have a relatively large neurologic deficit to qualify for this study. And just quickly, the way this works is these cells enter up through the bloodstream and they modulate inflammation. By modulating inflammation, that facilitates healing in the stroke patient. Dr Carolyn Lam:                Yeah, but wow. I mean bone marrow, biopsy and isolating the cells and so on. How is the study done? Greg Hundley:                   So, the key here is you've had your stroke, you're still in the hospital with a large neurologic deficit. And so day 11 to 17, you undergo a bone marrow biopsy. Then the cells are purified, and they're reinfused into your carotid artery by the way.                                                 And so, what was the study trying to do? Well, it was actually looking at the safety off all this. And what would the concern be? You're infusing these cells into the carotid artery. They go into the cerebral microcirculation, and those that are working in this field, are concerned is that going to promote more emboli? Is that going to promote thrombus? Extend the size of the infarct in the brain, et cetera?                                                 So, the investigators performed MRI's and neurologic exams. And what they found is the neurologic findings in the patients really didn't change, so there was no benefit. But the study wasn't set up to look for a benefit. And there were four patients that had a little bit of an enlargement of the stroke observed on MRI. So, a lot more to come in this basic science realm, but it's interesting to see investigators thinking about this in a whole different way, where we're harvesting one cell type from your body, and then infusing it up into the brain to sort of help rescue the situation. Dr Carolyn Lam:                Well, another paper dealing with stroke. This time, a Mendelian randomization study to explore whether genetically determined circulating levels of cytokines and growth factors, may be associated with stroke. And this was done in the mega stroke GWA data set and validated in the UK biobank, and it’s by Dr Dichgans and colleagues from the university hospital, Ludwig Maximilian University of Munich. They basically found, that a genetic predisposition to higher circulating levels of monocyte chemoattractant protein one, was associated with a higher risk of stroke. The associations also found for the etiology of the stroke subtypes, and especially for large artery stroke and cardioembolic stroke. In fact the genetically determined levels of this monocyte chemoattractant protein one, was also associated with higher risk of the related phenotypes of coronary artery disease and myocardial infarction. Greg Hundley:                   So, how do you bring this to practice in the clinic Carolyn? Dr Carolyn Lam:                So, this is still some steps away, but I do think that it very nicely supports the idea that inflammation as part of the pathogenesis of stroke, and of course additional work is needed to determine whether targeting the specific monocyte chemoattractant protein one, or it's downstream effectors, may be a meaningful strategy to lower stroke risk. So, terribly interesting. Greg Hundley:                   Yeah, you know it sounds like hitting inflammation or targeting that, is a real theme here from the basic science group. Well this is great Carolyn.                                                 And now, I guess we'll transition over to our feature article. Dr Carolyn Lam:                Absolutely. So, we're here to discuss the long-term results of the MOMENTUM 3 Trial, and that was a randomized controlled trial of the HeartMate 3 versus the Heartmate II left ventricular assist device. And this time, with a focus on stroke. The outcomes that's just so important to our patients. Greg and I are incredibly pleased to have with us, the authors, Dr Mandeep Mehra from Brigham and Women's Hospital, as well as our senior associate editor, Dr Biykem Bozkurt, to discuss this paper.                                                 Mandeep, perhaps just set the scene by telling us what this secondary analysis found? Dr Mandeep Mehra:       This analysis is really focused on the issue of stroke, as you pointed out. I'd like to just lace into context what this is important. Ever since the advent of left ventricular assist device therapy from the 80s and early 90s, to now, one of the major Achilles' heels, whether we have used pulsatile flow devices or non-pulsatile flow devices, has been the very constant occurrence of a high incidence of stroke, beyond the stroke rates were predominantly as compared to ischemic strokes. Then with the newer devices, we actually saw a reversal, where we began to see more ischemic strokes as opposed to hemorrhagic strokes, almost an equal parts at this time point.                                                 And this has been one of the critical reasons why we have not been able to expand the therapy beyond the very, very sick patient. Greg Hundley:                   Very nice. And another particular in the results here is, you didn't really see a difference in stroke rates, either hemorrhagic or ischemic strokes early, but you did start to see a difference after 180 days. Why do you think that's the case? Dr Mandeep Mehra:       That's a great point Greg. We really saw no difference in the first 30 days. When we analyzed this data, we divided it into a perioperative, a first 30-day time point. Then, we looked at the short-term time point up to 180 days or six months, and then beyond that to the two year end point. What became very clear is that most of the gains that we saw in the stroke rate, began to appear after the first 30 days, did not quite reach statistical significance at six months, but really the differences became heavily pronounced after six months, all the way out to two years.                                                 So, first point that I would make Greg, is that we did see differences beyond 30 days, it's just that they didn't reach conventional statistical significance. The second thing is, the more important point that you make, asking why that was the case. We actually think that the reason behind that, is that the first three months or so after that implant, really is a period of chaos in these patients, where the hemocompatibility, which is essentially the interface between the device as well as the patient, is attempting to be established. And it's very similar in a way as we see in heart transplantation Greg, where the real challenge in heart transplantation is between rejection and infection.                                                 And in the case of left ventricular assist device is the challenges between bleeding and thrombosis. It turns out that three months, whether it be transplantation or whether it be left ventricular assist devices, seems to be this period of chaos and adjustment, during which the patient and the device are starting to get to know each other.                                                 And this is why we think that most of the gains occurred after this period of chaos was overcome. Greg Hundley:                   No, it's really interesting that after accounting or adjusting for all the anticoagulant drugs, antiplatelet drugs, even the other medical therapies that were applied, you found these results. I mean, maybe also bring in Biykem here to answer the question, what is this machine doing that's providing such a benefit? Dr Biykem Bozkurt:         The two-year results being quite impressive for the HeartMate 3 are truly encouraging. Because I think we truly see a concordance benefit beyond 180 days, especially the nondisabling strokes, giving the hope to the providers that we can further perhaps enhance the field by focusing on optimization of anticoagulation strategies, prevention of atrial fibrillation, and maybe even consider our algorithms or pathways for stroke. Because, in this protocol, even though the stroke management was not standardized, and I'm sure that the data will not yield that information as to which centers were able to approach the stroke management in a perhaps evidence based approach, the sobering facts are regardless of the device, at two years, approximately half of the patients died. Even the non-disabling stroke patients had increased mortality compared to no-stroke patients.                                                 And if you examine evidence-based approaches, only one-third of the hemorrhagic stroke patients had reversal of anticoagulation, and a very small percentage ... actually, none of the patients had device intervention for the ischemic stroke. That raises the question of yes at two years the HeartMate 3 results are very promising. But, can we further even advance the field by doing evidence based standardized pathway driven stroke treatment approaches.                                                 The other very interesting finding from this trial is, in ENDURANCE trial, which was another trial with centrifugal device, HVAD device, there was an association of the stroke rates with inadequate control of blood pressure and anticoagulation, which was not noted in this trial. Maybe Mandeep can comment on do we truly have the adequate power to be able to infer whether blood pressure control and/or appropriate anticoagulation management strategies will matter? Dr Mandeep Mehra:       Biykem you've said it really well, and I'd like to just make some additional points with respect to the question. So, first of all Greg you're absolutely correct, that we tried to search for anything that would predict this reduction in stroke with the HeartMate 3, and it turned out that all we were left with is the device itself. So, it really begs the question, what is it about the device or it's interface that may have resulted in this.                                                 And of course, some of what I'm about to tell you will be speculation, but it may actually carry some water. So, for example, the HeartMate 3 is very unique in one other aspect, and that is that, even though it's a small profile device, it's engineering principles are such that it allows for very wide blood flow pathways. And in fact, despite its small profile, the blood flow pathways allow for 20 times more red blood cells to travel through the primary and secondary pathway, than other devices.                                                 What it means is that as blood is going through this device, it is exposed to very low sheer stress. And in return, the benefit that we see very clearly with this device in a very, very important way, is the fact that we see almost no denovo pump thrombosis developing with this device. Certainly, if the device doesn't carry some small quad risks in it, that cause problems with the device, it's probably also not causing the production of smaller non-device malfunction producing thrombi, which may with other devices, actually develop and cause strokes.                                                 So, we think that particular engineering enhancement, may play a very important role in reducing this stroke rate that we have observed.                                                 The second very important point that Biykem brought up, is this notion about the management of ... whether it be with anticoagulants or with blood pressure management. And for a moment let's dwell on the blood pressure issue. One of the striking things with the other centrifugal device, the HVAD device, is that the ENDURANCE Trial showed a significantly higher stroke rate with that device. And in fact, in a subsequent study, the ENDURANCE Supplemental Trial, when blood pressure was tightly, tightly controlled in the device, there appeared to be a small signal in reduction in strokes, although it still did not meet the non-inferiority endpoint, compared to the HeartMate II in the second supplementary trial that was done with that device.                                                 So, what's unique about this? Well, we can very clearly say maybe we just didn't have enough ability to show a difference in this particular trial, we didn't analyze it the right way, because we didn't have a blood pressure intervention or low or higher permissive blood pressures in this trial. But I would say that there's one other issue that I think may have played a very important role in this, and that is the HeartMate 3 is intrinsically developed with a fixed pulse algorithm. And in fact, the HeartMate 3 has a capacity where the magnetically levitated rotor upregulates itself and then downregulates itself every two seconds, and creates an internal pulsatility.                                                 Now, engineers developed that pulsatility to really decrease stasis, so that the pump wouldn't thrombose. But we often see that it provides sufficient peripheral pulsatility, not to the pulse pressures that we would normally like to see, but certainly to some degree, where the vasculature can perceive or transduce some degree of pulsatility. Why that may be important is, that it may actually allow for preservation of baroreceptor function in these patients, which tends to be lost in continuous flow pumps.                                                 And how important that is for blood pressure regulation and its vascular effect, may be something that needs to be looked at into the future. But it's certainly a very, very intriguing issue for us to examine. Dr Biykem Bozkurt:         Mandeep, one final question or comment. Do want to comment on the stroke rates of HeartMate II compared to former trials. Because that comes as a common query as to why in MOMENTUM 3 the stroke rate in HeartMate II, appear to be higher than the former trials. Dr Mandeep Mehra:       So very quickly, I'll tell you they're not. So, if you look at the 2009 randomized trials, randomized patients with a HeartMate II versus the HeartMate XVE trial, the two-year stroke rates with the HeartMate II in that trial were 19%, exactly what we observed at two years in this trial.                                                 Other trials have shown exactly that same number. The only trial in which there appeared to be a difference in those numbers, was in the ENDURANCE Trial, where the two-year rate of any stroke was 12%, and was a little lower in the HeartMate II than what we observed. However, I will caution you that if someone dies before having a stroke, then they die without a stroke. And so, stroke can sometimes we underestimated if the population that is enrolled, such as a transplant ineligible population at very high risk, is dying more often than having the chance of a stroke.                                                 So, I actually do not think at all that there was any difference whatsoever compared to prior trials. And even when you look at the ENDURANCE Supplement Trial, which is probably the most contemporary comparison of HeartMate II stroke rates, with MOMENTUM 3, the ENDURANCE Supplement Trial was only a one year trial, and the stroke rates even at one year were right on target with what we observed at the HeartMate II group in MOMENTUM 3. So, frankly that criticism is probably an unfounded criticism. Dr Biykem Bozkurt:         Thank you. Dr Carolyn Lam:                Wow, thank you Mandeep and Biykem, for really helping us go under the hood with this paper. I'm heart failure trained as well, but I learned so much, I'm sure our listeners did as well, and I'm sure you agree too Greg.                                                 Thank you so much for joining us today. Don't forget to tune in again next week.                                                 This program is Copyright American Heart Association 2019.  

Speaker 1:           Hi, everyone. Welcome to episode 21 of Getting Personal, Omics of the Heart from October 2018. I'm Jane Ferguson, an Assistant Professor at Vanderbilt University Medical Center and an Associate Editor at Circulation: Genomic and Precision Medicine. We have a great issue this month. So, let's dive straight in. First up, an article on "Loss-of-Function ABCC8 Mutations in Pulmonary Arterial Hypertension" from Michael Bohnen, Wendy Chung and colleagues from Columbia University. In pulmonary arterial hypertension, or PAH, compromised pulmonary arterial function can raise pressure in the pulmonary artery which leads to increased pulmonary vascular resistance. This ultimately results in right heart failure. While PAH is relatively rare, it has a high rate of mortality. Some genetic underpinnings have been identified, notably the KCNK3 gene identified by the same research group where they find that mutations result in potassium channelopathy. However, here the authors hypothesized that other genetic contributors also exist and that identification of these could highlight new therapeutic targets to improve treatment and outcomes in PAH. In their study, the authors performed exome sequencing for discovery of novel disease variants in 233 PAH patients, 99 of whom had pediatric-onset and 134 with adult-onset. They sequenced a replication sample of 680 individuals with adult-onset PAH. They found a de novo missense variant in the ABCC8 gene in one patient and then found 10 more ABCC8 variants in other unrelated patients in the discovery and replication samples. Half of these were novel mutations and all were located in conserved regions and predicted to be deleterious. They screened over 33,000 subjects from the Exome Aggregation Consortium and over 49,000 from the Regeneron-Geisinger DiscovEHR study and found significant overrepresentation on rare ABCC8 variants in the PAH cases compared with population controls. ABCC8 encodes sulfonylurea receptor ... part of the potassium ATP channel. The authors determined that it is expressed in lungs in both PAH and healthy individuals and is particularly localized to alveolar macrophages and proximal pulmonary arteries. They expressed eight of the newly discovered ABCC8 mutations in COS cells, which are a monkey-derived, fiberglass-like cell line and they assessed the effects on function. They used patch-clamp experiments to assess potassium ATP channel activity and recorded efflux rates of Rubidium-86. Every mutation was associated with impairments in one or both functional assays, suggesting that mutations in ABCC8 are responsible for PAH by a modulating potassium channel function and flux. An existing drug, Diazoxide, targets ABCC8 and has anti-hypertensive and insulin-lowering effects. The authors find that all mutants were pharmacologically activated by Diazoxide in the functional assays. Now, whether this drug would be safe or effective in PAH remains unknown, but these findings open up targeting of ABCC8 as a possible treatment in PaH and highlight the importance of potassium channels in PAH. Our next paper also used whole-exome sequencing for novel discovery. Marzia de Bortoli, Alessandra Rampazza and colleagues from the University of Padua in Italy published "Whole-Exome Sequencing Identifies Pathogenic Variants in TJP1 Gene Associated With Arrhythmogenic Cardiomyopathy". Arrhythmogenic Cardiomyopathy, or ACM, is one of the most common causes of sudden unexpected death in athletes and young people. It is known to be frequently caused by mutations in genes encoding mechanical junction proteins of the intercalated disks within the cardiac muscle. However, some individuals with ACM do not have any mutations in known genes. This research group was interested in finding novel causal gene mutation and they use whole-exome sequencing to identify mutations from a single patient in Italy. They used InSilica tools to screen for potentially damaging mutations which brought their list of candidate mutations down to 52 and this was topped by a novel mutation in the TJP1 gene which was predicted to be highly deleterious using various algorithms. Using Sanger sequencing, they found that this mutation was also present in several family members. A second mutation in TJP1, also predicted to be damaging, was identified in a second Italian family. They then screened a sample of 43 Dutch and German subjects diagnosed with ACM and found that, once again, mutations in TJP1 topped the list as predicted to be damaging. The TJP1, or tight junction protein 1, encodes the intercalated disk proteins ZO1. The identified mutations may affect folding and local interactions within the protein, affecting protein-protein interactions and gap junction organization. Well, within this paper, they were not able to fully disentangle the mechanisms linking these mutations to disease, given that the prevalence of TJP1 mutations in their ACM samples was almost 5%. Screening for TJP1 mutations in ACM cohorts may identify many additional affected subjects. Further research into TJP1 is needed to identify how these variants may cause ACM. If you want to read more about this paper, you can check out the accompanying editorial from Jason Roberts ... Western University, Ontario ... in this same issue. Next up is a paper from Natsuko Tamura, Yasuhiro Maejima, Mitsuaki Isobe and colleagues from Tokyo Medical and Dental University entitled "Single-nucleotide Polymorphism of the MLX Gene Is Associated With Takayasu Arteritis". Takayasu Arteritis, or TAK, is an autoimmune disease causing aortic vasculitis that is poorly understood and disproportionately affects young Asian women. In previous genome-wide associations, study of TAK in Japanese individuals conducted by this group, indicated SNPs in the MLX gene. In this paper, the authors aim to identify mechanisms linking MLX mutations with TAK. The top GWAS SNP rs665268 is a missense mutation causing L-Glutamine Arginine substitution in the DNA binding site of MLX. They found that this SNP was associated with severity in disease in TAK. With additional copies of the risk alleles associated with more severe aortic regurgitation and greater number arterial lesions. In mice, the highest expression of MLX was found in the aortic valves. Using crystallography, they found that the missense mutation likely stabilizes a complex formed between MLX and MondoA. Immunoprecipitation experiments confirmed that the missense mutation was associated with enhanced MLX MondoA heterodimer formation and MLX transcriptional activity. This resulted in upregulation of TXNIP and higher TXNIP expression is associated with increased intracellular oxidative stress and the authors found for increased oxidative stress in cells carrying the MLX mutation. Further, additional cell experiments showed evidence of this MLX mutation reduces autophagy and stimulates inflammasome activation. Overall, through a series of really elegant experiments, the authors demonstrate that a missense mutation in MLX leads to inflammasome activation and accumulation of cells within the aorta, potentially underlying the pathophysiology seen in TAK patients and highlighting novel causal pathways that may be probed therapeutically.regular Our next paper from Danxin Wang, Wolfgang Sadee and colleagues from the University of Florida and The Ohio State University, also delves into the functional impact of disease-associated SNPs. In their paper, "Interactions Between Regulatory Variants in CYP7A1 Promoter and Enhancer Regions Regulate CYP7A1 Expression", they used a series of experiments to demonstrate how SNPs in CYP7A1 ... which have been associated with cholesterol and cardiovascular disease ... are related to gene function. CYP7A1 is a gene which coordinates a key pathway for cholesterol removal from the body because it encodes an enzyme which is rate-limiting for bioassay synthesis from cholesterol. Although several SNPs in the gene have been associated with cardiovascular phenotypes, the reported effects on gene function have been inconsistent and/or unclear. Because of the linkage disequilibrium between SNPs, it has been hard to understand which SNP or SNPs are actually functional. What this team set out to do was to systematically screen functionality of individual CYP7A1 SNPs to understand the independent effects of each functional variant. First, they used chromatin conformation capture, or 4C assay, to identify regions that associated with a CYP7A1 promoter. They found three distinct regions with evidence of enhancer function and [phonetic 00:09:05] active A>G regulation. They, next, used CRISPR Cas9 to delete each of the three regions in HepG2 cells and assess effects on CYP7A1 expression. One region had no effect, while one led to increased expression and one led to decreased expression ... thus, identifying the presence of both enhancer and repressor regions. Using reporter gene assays, they confirmed the effects seen in CRISPR experiments. Based on reported SNP associations, they narrowed down candidate functional SNPs within the regions and constructed reporter assays containing haplotypes of potential functional SNPs. They were able to identify two SNPs acting together to determine differences in CYP7A1 gene expression. Because these SNPs are in LD, but the minor alleles have effects in opposite directions, considering genotype at both SNPs is required to understand the effects on gene expression. This explains why previous studies found inconsistent results. Both during the functional experiments, they went to human samples and they assessed the combined effect of the two SNPs on clinical phenotypes. Designating people as high or low activity based on the two SNPs, they found significant differences in cholesterol and in the likelihood to reach cholesterol targets on statin, as well as in the risk of MI. This paper is a lovely example of how careful functional interrogation can tease out a complex problem and I think it highlights how much more of this type of work needs to be done for the many other genomic regions with confusing or discord in associations. The last full-length article concerns the "Effect of Ascertainment Bias on Estimates of Patient Mortality in Inherited Cardiac Diseases" and comes from Eline Nannenberg, Imke Christiaans and colleagues at the Academic Medical Center, Amsterdam. They were interested in how much ascertainment bias and the tendency to publish findings from more severe disease cases affects the mortality estimates that are used to guide clinicians and genetic counselors when helping patients understand their disease prognosis. They revisited three inherited cardiac diseases including idiopathic ventricular fibrillation associated with a mutation in DPP6, SCN5A overlap syndrome associated with SCN5A mutations, and Arrhythmogenic Cardiomyopathy caused by a founder PLN mutation. They analyzed mortality over 2-10 years of clinical screening and cascade screening and found that the median age of survival quickly increased in all three conditions. In many cases, the reason that a mutation was identified was because of severe disease in that patient or family, but as the authors highlight here, this can bias publications towards associating the variant with more severe phenotypes and higher mortality. Following up the initial findings with additional screening and tracking of affected individuals is important to subsequently give a more accurate estimation of the effect of the mutation which can be used to inform treatment plans. Moving on to this month's research letters, Catherine Hajek, Jerome Rotter and colleagues from LA BioMed and the University of South Dakota, published the results of their study, "A Coronary Heart Disease Genetic Risk Score Predicts Cardiovascular Disease Risk in Men, Not Women: The Multi-Ethnic Study of Atherosclerosis". The genetic risk scores are being increasingly applied to estimate disease risk in individuals. However, these scores are based on the GWAS discovery from specific populations which have often been disproportionately male and with individuals of European ancestry. In this letter, the authors wanted to understand whether coronary heart disease genetic risk scores performed the same in men and women of European ancestry. Using data from the MESA Study, they applied a 46 locus genetic risk score to over 2500 individuals. In men, this risk score was strongly associated with event rates. However, in women, there was no association. Given the known differences in disease pathophysiology and manifestation between men and women, this finding additionally highlights the need to conduct genetic studies in underrepresented groups so that we can design scores that accurately predict risk within specific groups. Our next letter comes from Xiao Wang and Kiran Musunru at the University of Pennsylvania ... "Confirmation of Causal rs9349379- PHACTR1 Expression Quantitative Trait Locus in iPSC Endothelial Cells". They were interested in understanding the affect of a coronary disease SNP in the PHACTR1 gene on gene expression. Previous efforts to investigate this had yielded conflicting results showing either a significant eQTL effect for PHACTR1 and vascular tissue or no effect on PHACTR1, but an effect on a distal gene EDN1 in endothelial cells. For this study, the authors used CRISPR Cas9 to introduce the SNP to iPS cells and then expanded isogenic lines at the major and minor allele homozygous and differentiated these into endothelial cells. They find that the major allele was associated with significantly higher factorial expression, but no difference in EDN1 expression. Thus, based on these experiments, it appears that PHACTR1 may indeed be the causal gene in that region underlying the GWAS signal and whether or not EDN1 is involved remains unclear. Our next letter is a clinical letter from Nosheen Raza, Anjali Owens and co-authors at the University of Pennsylvania. They report on "ACTA1 Novel Likely Pathogenic Variant in a Family With Dilated Cardiomyopathy". In this case report, they describe that the discovery of a mutation in ACTA1 in a family with dilated cardiomyopathy, but no skeletal muscle symptoms. As a gene that is predominantly expressed in skeletal muscle, ACTA1 mutations have previously been associated with skeletal muscle myopathies and would not have been expected to cause cardiac symptoms in the absence of skeletal muscle dysfunction. However, sequencing suggests that this variant is a causal mutation in this family, highlighting the need to consider potential mechanisms for cardiac muscle specifics of highly expressed skeletal muscle genes. Our second clinical letter comes from Laura Zahavich, Seema Mital and co-authors from the Hospital for Sick Children in Ontario. They report a "Novel Association of a De Novo CALM2 Mutation With Long QT Syndrome and Hypertrophic Cardiomyopathy". They report finding mutation in the calcium transporter CALM2 gene in the child who presented with hypertrophic cardiomyopathy and ultimately died from sudden cardiac death. While this patient also had some variants of un-insignificance, the CALM2 gene is highly conserved and mutations are likely to be pathogenic. The CALM2 is not on all of the clinical genetic testing panels and in this case, whole-exome sequencing was required to identify a mutation. CALM2 have been described in other individuals and together with the findings reported here, there's compelling evidence for inclusion of CALM2 on cardiomyopathy in clinical testing panels. This issue also contains a perspective article from Michael Mackley, Elizabeth Ormondroyd and colleagues from the University of Oxford entitled "From Genotype to Phenotype: Clinical Assessment and Participant Perspective of a Secondary Genomic Finding Associated with Long QT Syndrome". They describe some of the challenges arising from more widespread genetic testing including how to deal with incidental findings. A larger number of people including apparently healthy individuals are receiving sequencing results that highlight potential disease-related mutations, but with varying penetrance and uncertain effects. This perspective paper highlights the issues through case study and discusses future directions and challenges in this rapidly growing area. Finally, we ride out this issue with an AHA scientific statement on "Cardiovascular Health in Turner Syndrome: A Scientific Statement From the American Heart Association" led by Michael Silberbach and Jolien Roos-Hesselink and a group of co-authors representing the American Heart Association Council on Cardiovascular Disease in the Young; Council on Genomic and Precision Medicine; and Council on Peripheral Vascular Disease. In this statement, they discuss the cardiovascular complications that commonly occur in girls and women Turner syndrome. Cardiovascular disease contributes significantly to premature death in individuals with Turner syndrome. Because of the unique nature of the cardiac presentations in Turner syndrome, better clinical guidelines are needed to improve diagnosis and treatment of [phonetic 00:17:26] ischemia in these individuals. This statement takes a first step to outline suggestions to improve clinical practice and highlights the work that still remains to be done to inform disease management. That rounds out the October issue of Circulation: Genomic and Precision Medicine. Thanks for listening! You can go online to ahajournals.org/journal/circgen to access the latest issue and browse previous issues. As a last reminder, AHA Sessions is approaching fast and I hope to see many of you in Chicago, November 10-12. This podcast was brought to you by Circulation: Genomic and Precision Medicine and the American Heart Association Council on Genomic and Precision Medicine. This program is Copyright American Heart Association, 2018.