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Circulation on the Run


Jun 21, 2021

First join author Marc Dweck and Associate Editor Victoria Delgado as they discuss the article "Effect of Denosumab or Alendronic Acid on the Progression of Aortic Stenosis: A Double-Blind Randomized Controlled Trial." Then, join authors Torbjørn Omland and Geeta Gulati as they discuss the article "Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy (PRADA) Extended Follow-Up of a 2×2 Factorial, Randomized, Placebo-Controlled, Double-Blind Clinical Trial of Candesartan and Metoprolol."

Dr. Carolyn Lam:

Welcome to Circulation On The Run. Your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam Associate Editor from the National Heart Center and Duke National University of Singapore.

Dr. Greg Hundley:

I'm Dr. Greg Hundley, Associate Editor, Director of the Pauley Heart Center, VCU Health in Richmond, Virginia.

Dr. Carolyn Lam:

Hooray, it's another double feature week! And guess what, these two papers are two randomized control trials. One looking at progression of aortic stenosis and the other, looking at a prevention of cardiac dysfunction following adjuvant breast cancer therapies.

Dr. Carolyn Lam:

So, very interesting two papers coming right up. But Greg, why don't you start by highlighting some of your favorite papers from today's issue.

Dr. Greg Hundley:

You bet Carolyn.

Dr. Greg Hundley:

So my first study was conducted by Dr. Gabriela Trifan and colleagues from University of Illinois who performed a meta analysis of major studies that compare the efficacy and safety of dual anti-platelet therapy versus monotherapy for secondary prevention of recurrent stroke or transient ischemic attack in those previously experiencing minor non cardioembolic stroke. And their primary outcomes were stroke and the composite of stroke, TIA, acute coronary syndrome and death of all cause. And the safety outcome was major hemorrhage.

Dr. Carolyn Lam:

Oh, okay. Very important study. What did they find?

Dr. Greg Hundley:

Right Carolyn. So the analysis included 27,358 patients. And compared with monotherapy, dual anti-platelet therapy reduced the risk of recurrent stroke and the composite outcome, but increased the risk of major bleeding. And in subgroup analysis at less than or equal to 30 days, dual anti-platelet therapy increased the risk of hemorrhage relative to monotherapy. In sensitivity analyses, the risk for hemorrhage with less than or equal to 30 days of dual anti-platelet therapy, after excluding the combination of aspirin plus Ticagrelor, was comparable to monotherapy. However, the risk of stroke recurrence and composite outcomes in the subgroup and sensitivity analyses remained decreased compared to monotherapy.

Dr. Greg Hundley:

And so Carolyn, the take-home message from this paper is that dual anti-platelet therapy decreases the risk of recurrent stroke and composite events compared with monotherapy. But, dual anti-platelet therapy increases the risk of major hemorrhage, except if the treatment is limited to 30 days and does not include the combination of aspirin plus Ticagrelor.

Dr. Carolyn Lam:

Ah, thanks for that last take home message. Thank you.

Dr. Carolyn Lam:

Well, the paper I'm going to tell you about is the first to examine the role of epicardial fat derived extracellular vesicles in the pathogenesis of atrial fibrillation. And this comes from Dr. Leor from Sheba Medical Center, Tel Aviv University in Israel and his colleagues who collected epicardial fat specimens from patients with and without atrial fibrillation during elective heart surgery.

Dr. Carolyn Lam:

Epicardial fat samples were grown as organ cultures and the culture medium was collected every two days. And the authors then isolated and purify these epicardial fat extracellular vesicles from the culture medium.

Dr. Carolyn Lam:

They found that epicardial fat extracellular vesicles of patients with atrial fibrillation had unique pro-inflammatory, profibrotic and proarrhythmic properties. Epicardial fat extracellular vesicles could in fact induce cellular, molecular and electrophysiological remodeling that could result in atrial fibrosis, myopathy and the development of atrial fibrillation.

Dr. Greg Hundley:

Wow Carolyn, so what are the clinical implications of epicardial fat extracellular vesicles?

Dr. Carolyn Lam:

Hmm, good question. Well, understanding their role in the pathogenesis of atrial fibrillation may for one lead to the discovery of new diagnostic markers or new targets for the prevention and treatment of atrial fibrillation. And that combined pro-inflammatory profibrotic and proarrhythmic effects of these epicardial fat and extracellular vesicles may in fact be relevant to the pathogenesis of other cardiovascular diseases associated with obesity and abnormal adipose tissue deposition.

Dr. Greg Hundley:

Very nice Carolyn.

Dr. Greg Hundley:

My next paper comes again to us from the world of preclinical science and these authors led by Dr. Masanori Aikawa from Harvard Medical School applied a systems approach in mouse experiments to discovering therapeutic targets for vein graft failure. They use global proteomics and high dimensional clustering on multiple vein graft tissues to identify potential pathogenic mechanisms. And experiments were conducted in both in vivo mouse models and in vitro human macrophages.

Dr. Carolyn Lam:

Oh wow. So what did they find?

Dr. Greg Hundley:

So Carolyn, peroxisomes proliferator activated receptors or PPAR alpha agonism by pemafibrate retarded the development and inflammation of vein graft lesions in mice, while gene silencing worsened plaque formation. Pemafibrate also suppressed arteriovenous fistula lesion development.

Dr. Greg Hundley:

Now, metabolomics, lipidomics, functional metabolic assays and single cell analysis of cultured human macrophages revealed that PPAR alpha modulates macrophage glycolosis, citrate metabolism, mitochondrial membrane sphingolipid metabolism and heterogeneity.

Dr. Carolyn Lam:

Okay. So what is the take home message Greg?

Dr. Greg Hundley:

Right Carolyn, thought you would ask me that.

Dr. Greg Hundley:

So PPAR alpha activation suppresses the development of vein graft and arterial venous fistula lesions. And PPAR alpha reduces macrophage activation by influencing macrophage heterogeneity, mitochondrial integrity, and the metabolome. So Carolyn, given that peripheral arterial disease and chronic kidney disease prevalences are increasing, warranting needs for more vein grafts and arterial venous fistulas, this target discovery platform is applicable to investigating therapies for these diseases.

Dr. Greg Hundley:

And a really nice accompanying editorial is provided by doctors Reilly and Bornfeldt.

Dr. Greg Hundley:

Well Carolyn, how about we turn to look at what is in the mailbag this week?

Dr. Carolyn Lam:

Well let me tell you about it Greg. We've got a cardiovascular case series by Dr. Borlaug on things are not always as they seem, multimodality exercise assessment and evaluation of dyspnea. In cardiology news by Kuhn there's a discussion of Evinecumab approval adds a new option for homozygous familial hypercholesterolemia with a hefty price tag. A perspective piece by Dr. Watkins on time to think differently about sarcomere negative hypertrophic cardiomyopathy. And finally a research letter by Dr. Ahn on reduction in Kawasaki disease after non-pharmaceutical interventions in the COVID-19 era, a nationwide observational study in Korea.

Dr. Carolyn Lam:

Wow. That wraps it up for the summaries. Let's go on to the feature discussions shall we, Greg?

Dr. Greg Hundley:

You bet.

Dr. Carolyn Lam:

We are about to talk about the extended follow-up results of the PRADA trial. Oh, so interesting. So happy to have with us today, doctors Geeta Gulati and Dr. Torbjørn Omland, both from the Akershus University hospital in Norway, and you would probably recognize that Dr. Torbjørn Omland is also one of our associate editors, but both here are the co-corresponding authors of this beautiful paper.

Dr. Carolyn Lam:

Thank you so much for coming here today. Torbjørn, maybe you could start with what is the PRADA trial? Why did you decide to do an extended follow-up?

Dr. Torbjørn Omland:

Yeah so PRADA was a two times two factorial randomized double blind clinical trial that sought to evaluate the effects of intervention with receptor blocker Candesartan. And a beta blocker Metoprolol in patients with early breast cancer who received anthracycline therapy as part of their chemotherapy. And then we wanted to assess the effect of this sort of preventative therapy, left ventricular function and injury.

Dr. Torbjørn Omland:

So we reported the primary results of the trial a few years ago and showed that intervention with Candesartan most associated with a significant elevation of the reduction in left ventricular ejection fraction that these patients may experience, and also that treatment with the beta blocker Metoprolol was associated with an intimation of the increase in cardio proponents suggesting a beneficial effect on myocardial injury. However, whether these results were or these effects were sustained after termination of the study drugs was unknown. And that was what we really wanted to address with extended follow-up study.

Dr. Carolyn Lam:

Yeah, makes a lot of sense, especially because these injuries I suppose could still continue. And just to be very clear, the medications though were only taken during the adjuvant chemotherapy and therefore could be a variable duration from what I understand. Right? Great.

Dr. Carolyn Lam:

So Geeta then, could you tell us what did the extended analysis show?

Dr. Geeta Gulati:

The extended follow-up was interesting and it was something we really wanted to figure out because there are not many studies who have been done on the extended follow-up and you're not giving these study medications afterwards.

Dr. Geeta Gulati:

So very interestingly we saw that the decline in the ejection fraction was still there in the whole group. But this time there was no difference in the group who received Candesartan do those who didn't. And we show that there was a different in the primary results, but now in the extended follow-up there was no difference. And then also in the Metoprolol group that had previously shown that there was lesser rise in the troponins. Again, there was no difference in the groups now on the extended follow-up.

Dr. Geeta Gulati:

So this is very interesting because this shows that there is a small, modest decline in a left ventricular ejection fraction during and after the breast cancer therapy. But what does this really mean? It's a small decline and it's within the normal range and the cardioprotection is not working. So, are we perhaps looking at the wrong group? Perhaps we should look at patients who have the higher cardiovascular risk factors. Perhaps even we should look at more novel heart failure or cardiac drugs that may have a stronger effect on the ejection fraction.

Dr. Carolyn Lam:

Right. So Geeta though, can we unpack that a little bit? You see, the patients were not on the medication anymore at the time of follow-up. So you're saying that even though they were given adjuvant chemotherapy and covered with the drug, that even not having any more chemotherapy, their ejection fraction still fell. And if I'm not wrong, this was an MRI analysis. And so it was only by an ejection fraction of two percent on mean fall, right? How do we think about that clinically?

Dr. Geeta Gulati:

And that's the important question, isn't it? Because a decline in the ejection fraction of less than two percent within the normal range, what does it really mean? Well initially we thought that if there was a different in those who had cardioprotective medication compared to those that didn't, it may prevent development of further decline in the cardiac function and then heart failure in the future. But now, there is really no difference between the groups. So perhaps the clinical implication of giving cardio protection to all cancer patients is not really that useful. Perhaps they should look at those who are at higher risk because they would have a greater fall in ejection fraction and then more cardioprotective effect of these drugs.

Dr. Carolyn Lam:

Yeah, totally. And perhaps the metrics that we're used to seeing in the past with greater falls of ejection fraction, maybe it just doesn't apply currently or perhaps with the specific chemotherapeutic regimens perhaps that you're using now. Because with a very small fall, and I believe you only had one heart failure event, right? If I'm not wrong in this extended follow-up. So, just to let the audience know, it was very small fall, little number of events. It's hard to really tease apart what that clinically means. Now, could I ask though, does it mean we need actually a more sensitive marker? Because there was some interesting stuff about global longitudinal strain. Could you-

Dr. Geeta Gulati:

I would throw that question back to Torbjørn I think.

Dr. Torbjørn Omland:

Yes. So that's a very interesting question Carolyn. So we did observe what seemed to be a beneficial, but a sort of minor effect on global longitudinal strain. So we know that that is the more sensitive index of systolic function than left ventricular ejection fraction, that was the pre defined primary outcome. So that's raises of course questions whether a future trial should more focus on these more sensitive indices of cardiac function.

Dr. Carolyn Lam:

Yeah. Geeta, could I then really put it back to you? And the tough question I always get, how do we apply these results clinically then? I mean, you see these patients right? Now what? Do you give or do you don't give? And which one do you give? And how do you identify high risk patients? I don't know.

Dr. Geeta Gulati:

Again, I think all the patients are unique aren't they? So that's where we have to start. So in my clinic, if I have a high risk patient with hypertension, diabetes, hypercholesterolemia, yeah perhaps they even have had a cardiovascular disease before something like this. Then I will take more care of these patients and be more careful with the echo measurements I'm doing and if I find that they have a decline in their cardiac function, I may be more eager to start them on cardioprotective medication.

Dr. Geeta Gulati:

But then in R-Regen we follow all the HER two positive breast cancers with echo. If I don't have echoparamaties that clearly tells me that they have a decline in the cardiac function, then I may wait to start cardio protection because none of the studies has really so far show that all patients should have these cardioprotective medication or prevention.

Dr. Carolyn Lam:

Nice. Thank you. That was a tough one to get at. And I suppose Torbjørn I have to give you another tough one then. Because how to address the remaining unanswered questions, right? Because one of them on my mind too, is how to identify the high risk, do biomarkers play a role? And then the other is if we then start the preventive therapies like ERBs and beta blockers, should we actually continue it forever? And so on. But anyway Torbjørn please, please, what does the future hold?

Dr. Torbjørn Omland:

I think it's worthy of a recap or underscoring that these are really good news for many breast cancer patients that actually the risk of an important decline in ventricular function is lower than we thought. So that may be because of several things. I think in general, those whose used these cardiotoxic drugs are lower. And we also, I think that there's increased collaboration between oncologists and cardiologists. Also meaning that we are better to pick up the high-risk patients at an early stage.

Dr. Torbjørn Omland:

But of course, it's very important questions that you asked regarding how to identify the high risk patients. And I think that's where really future research should focus. So there we know that traditional risk factors are important. We are looking into whether biomarkers can be used, if there's more sensitive imaging in this can be used. But so far we haven't really succeeded in getting the risk model that really identifies it on the patient level. So that's work that remains to be done.

Dr. Torbjørn Omland:

And then we are also looking for new types of intervention, good exercise, good other drugs. We are doing now a PRADA two study where we look at the effects of Sacubitril Valsartan in this setting. And those are also very exciting, I think, and we look very much forward to present that in the future.

Dr. Carolyn Lam:

Oh wow thank you so much Torbjørn and Geeta. The PRADA two trial. I've got to ask you, why do you then call it the Chanel trial? But I think I'll save that for another day. So thank you. Thank you once again, this is fabulous and congratulations to you both.

Dr. Torbjørn Omland:

Thank you.

Dr. Geeta Gulati:

Thank you.

Dr. Greg Hundley:

Well listeners, welcome to our second feature discussion today. And we have with us Dr. Marc Dweck from University of Edinburgh in Scotland and our own associate editor, Victoria Delgado from Leiden in the Netherlands. Welcome to both of you.

Dr. Greg Hundley:

Marc, we're going to get started with you. Could you tell us a little bit about the background for your study and what was the hypothesis that you wanted to test?

Dr. Marc Dweck:

Thanks very much Greg for the invitation. So I guess aortic stenosis is perhaps the last major cardiovascular condition where we don't have a medical therapy. We're unable to treat these patients. We're unable to prevent progression. We're only left with a valve replacement. And so we, like a lot of groups around the world, want to develop a treatment for aortic stenosis. Our group did the first SALTIRE trial, where we looked at statins seeing if we could slow aortic stenosis progression. And that, like similar trials, was neutral. No effect on the valve progression.

Dr. Marc Dweck:

And so actually I've spent the last 10 years looking at some of the factors associated with aortic stenosis progression in particular. The answers that we've had from those trials have kind of come back telling us that really it's a process of calcification. If you look at what triggers progressive valve narrowness is this calcific process, that seems to be a self perpetuating disease.

Dr. Marc Dweck:

So the question is, how do you target this calcification process? How can you interrupt it? And how can you do that without compromising bone health in these elderly patients? So in trying to come up with a solution to that we thought about using osteopetrosis agents, which we hypothesized would maintain both bone health and reduce vascular calcification on the basis of observational data and also animal data suggesting that. And that was really where we came from in the design of the SALTIRE two trial.

Dr. Marc Dweck:

And doing a big trial with clinical endpoints wasn't felt to be feasible and instead we decided to look at imaging end points and see whether we could slow disease progression using these agents.

Dr. Greg Hundley:

Very nice Marc. And so you're really leading us into, tell us a little bit more about your study population and your study design.

Dr. Marc Dweck:

Yeah so we wanted to take patients from our outpatient clinic with mild, moderate and even early severe disease, asymptomatic patients crucially, patients that aren't scheduled for aortic valve replacement and see the effects of these drugs on disease progression.

Dr. Marc Dweck:

So we did a randomized control trial. There was three arms. Patients were randomized to Alendronate, Denosumab, these are the two osteopetrosis agents, or placebo. We then did a series of baseline imaging tests. So the primary end point was based on CT calcium scoring. So they had a baseline CT calcium score. They also had a baseline echocardiogram and they had a baseline fluoride PET scan. So this measures calcification activity in the valve. And then we essentially repeated those tests after a period of time on the drugs, or on placebo. We repeated the calcium score and the echo after two years and repeated the PET scan after one year.

Dr. Greg Hundley:

Very nice, and so before you tell us your results, a little bit, how many patients? And maybe their average age and the rough distribution of men versus women.

Dr. Marc Dweck:

Yeah so study recruited roughly 50 patients in each arm. The average age was 72 and there was 21% females in the study. So, like a lot of studies in aortic stenosis, a low female prevalence. Despite our best efforts, that's something we need to attend to in the future, but otherwise, a representative age group and patients with this disease.

Dr. Greg Hundley:

And what did you find?

Dr. Marc Dweck:

Well we found that the drugs didn't have an effect on any of these imaging assessments. So, there was no effect on the progression for CT calcium score at two years, no effects on any of the echocardiographic assessments of hemodynamic severity, and no effect on calcification activity as measured with the fluoride.

Dr. Marc Dweck:

So a very consistent result using multiple different imaging modalities, which I think gives us confidence that there isn't at least a dramatic effect of these drugs on disease activity or disease progression, in aortic stenosis.

Dr. Greg Hundley:

Very good. Well listeners, we're now going to turn to one of our associate editors, Dr. Victoria Delgado, and she is really a valvular heart disease expert member of our team.

Dr. Greg Hundley:

Victoria, I know you see a lot of papers that kind of come across your desk. What attracted you to this manuscript? And then how do you put the results in the context of other research that's going on to halt the progression of aortic stenosis.

Dr. Victoria Delgado:

Thank you Greg. So first the first thing that attracted my attention for this article is the question. We know that we don't have any medical therapy for halting the progression of aortic stenosis. And even if the previous studies have been negative or neutral, still there is the interest of trying to find a less invasive therapy for these patients, or even prevent that they arrive to surgical or transcatheter aortic valve replacement.

Dr. Victoria Delgado:

And the second is that these are very strong analysis because it's a randomized clinical trial and using as end points imaging. So that trial also in a way answers the question of which imaging technique we need to use in order to see the effects of specific therapies. Previous studies have used mainly echocardiography, but that only gave us information on the modynamic effects of the aortic stenosis. While in this study, we have the combination of CT and a combination of a PET that he give us also information on how the calcification is happening. So that makes the study very comprehensive and give us more insights into this pathophysiology, to this pathology particularly.

Dr. Greg Hundley:

Very nice. So it sounds like looking at aortic stenosis from multiple different angles, whether it be echocardiography or perhaps imaging processes that look at the progression of calcification.

Dr. Greg Hundley:

Well, Marc, I want to come back to you. What do you think is the next, sounds like you've been working in this area for an extended period of time. What do you see as the next research study that you and your group may undertake in this area?

Dr. Marc Dweck:

I Think we've got the study design about right. I think if in the future studies we want to do, I think we would adopt a similar design using these imaging end points.

Dr. Marc Dweck:

I have to say I'm very influenced by the recovery trial that has been conducted in the UK with COVID. I mean, here's a disease where we wanted to get a treatment as quickly as we can. And in doing that, developing a platform type trial where you potentially test multiple different promising agents simultaneously across multiple centers across the world or the UK, I think that would be the quickest way to developing a treatment. And so I'm encouraged that there are five or six very good targets where we could, for a new therapy in aortic stenosis. And I think a platform type design where we engage multiple groups using imaging as that initial end point. And then, the drugs that appear to have an effect on these imaging end points we can start to recruit more patients at those sites, into those centers, looking for clinical end points.

Dr. Marc Dweck:

I think that kind of discussion is happening around the world now between groups that are interested because we want to crack this problem quickly. We don't want to wait and do these different studies sequentially. We want to try and do them simultaneously. And I'm excited about that. I think if we do that, we've got a real shot at developing a treatment over the next five to 10 years say.

Dr. Greg Hundley:

Fantastic.

Dr. Greg Hundley:

And Victoria, I know you have interest in this particular area. Do you have anything you'd like to add?

Dr. Victoria Delgado:

Yeah. I think that those studies that Mark said are really welcome and I hope that they are positive. And give us a little bit of more to treat these patients. My main fear is that these patients are not as frequent, for example, as heart failure patients. Where we have several therapies where we have possibility to enroll patients in trials for new drugs, that we know that probably are going to be effective. But for valvular heart disease it has been always the end point to reach surgery or to reach an aortic valve replacement or indication of the mitral valve and mitral valve repair. So in early phase of the disease, my main concern is that maybe the patient is not going to be well-trained to understand what are the consequences. I want to always wait until maybe when is needed for the surgical or transcatheter procedure.

Dr. Victoria Delgado:

But I think that increasing the awareness of the prevalence of valvular heart disease and the consequences may help people to understand, to put more attention for an early diagnosis and develop new drugs that can help, like in this case, aortic stenosis one of the most frequent valvular heart disease, to prevent the proliferation and to prevent the replacement of the valve.

Dr. Greg Hundley:

Very nice. Well listeners, this has been a wonderful discussion and we greatly appreciate the input that we've been able to gather today from Dr. Marc Dweck from Edinburgh in Scotland and our own associate editor, Dr. Victoria Delgado. Bringing this information from a randomized trial, evaluating osteoporosis drugs, and really indicating they did not disrupt the progression of calcification in patients with aortic stenosis.

Dr. Greg Hundley:

Well, on behalf of Carolyn and myself, we want to wish you a great rest of your week and we will catch you next week on The Run.

Dr. Greg Hundley:

This program is copyright of the American Heart Association, 2021. 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, visit ahajournals.org.