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Circulation on the Run

Apr 13, 2020

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: I'm Greg Hundley, associate editor from the VCU Pauley Heart Center in Richmond, Virginia.

Dr Carolyn Lam: Greg, amyloid cardiomyopathy is the rage. I cannot tell you the number of discussions I've had on the topic. Of course, it was tafamidis, the amazing results with that trial that really made us realize we need to pick this up. But have you ever thought about the cost effectiveness of tafamidis for amyloid cardiomyopathy? Well, guess what? We're going to have a whole feature discussion just about that. But first let's go to our summary, shall we?

Dr Greg Hundley: You bet, Carolyn. Well, let me get started. I'm going to talk about regulation of cell cycle growth as well as division in regard to cardiac regeneration. My first paper comes from Dr Lior Zangi from the Mount Sinai School of Medicine. Well, Carolyn, have you ever wondered why the adult mammalian heart has limited regenerative capacity?

Dr Carolyn Lam: All the time, Greg.

Dr Greg Hundley: Well, of course you have. It's mostly due to postnatal cardiomyocyte cell cycle arrest. In this study the investigators evaluated the effect of pyruvate kinase muscle isozyme 2 and cardiomyocytes through models of loss, that is cardiomyocyte specific PKM2 deletion during cardiac development or gain using cardiomyocytes specific PKM to modified mRNA to evaluate PKM to function and regenerative effects post-acute or chronic MI in mice.

Dr Carolyn Lam: Nicely described. What did they find, Greg?

Dr Greg Hundley: What they found is that PKM2 is expressed in cardiomyocytes during development and immediately after birth, but not during adulthood. Using cardiomyocytes PKM to modified RNA, they found that cardiomyocyte targeted strategy following acute or chronic MI resulted in increased cardiomyocyte cell division, enhanced cardiac function, and improved long-term survival. They found that PKM2 regulates the cardiomyocyte cell cycle and reduces oxidative stress damage through anabolic pathways and beta-catenin.

Dr Carolyn Lam: Cool, Greg. Man, this cardiac regeneration really, really is a hot area.

Dr Greg Hundley: Carolyn, that is so insightful because these results really impact research toward unlocking pathways that could be involved in induction of myocyte cell division and regeneration in those sustaining MI or conditions like MI.

Dr Carolyn Lam: Nice. Well, Greg, I'm going to change tones here and ask you, can we prevent atrial fibrillation with treatments for diabetes? Well, guess what? We have a paper next. It's from Dr Wiviott from the TIMI Study Group and his colleagues who really reason that since atrial fibrillation is associated with hypertension, obesity and heart failure in patients with diabetes and SGLT2 inhibitors have been shown to lower blood pressure, reduce weight, and reduce hospitalization for heart failure in these patients, perhaps SGLT2 inhibitors may also reduce the risk of atrial fibrillation. They explored the effect of Dapagliflozin on the first and total number of atrial fibrillation and atrial flutter events in patients from the DECLARE-TIMI 58. As a reminder, they had type two diabetes with either multiple risk factors for or known atherosclerotic cardiovascular disease.

Now importantly, atrial fibrillation events were identified by a search of the safety database using these MedDAR preferred terms. Now what they found was Dapagliflozin reduced the risk of atrial fibrillation events during follow-up as well as the total number of atrial fibrillation events in patients with type two diabetes. These reductions were consistent across major subgroups including sex, presence of atherosclerotic cardiovascular disease, history of atrial fibrillation, history of heart failure, history of ischemic stroke, HBA1C groups, body mass index groups, blood pressure or EGFR. They looked at all these subgroups because these are all clinical factors, well established, with associations with the risk of atrial fibrillation.

Dr Greg Hundley: Wow, Carolyn. Another sort of feather in the cap for the SGLT2 inhibitors. What does this mean for clinical practice?

Dr Carolyn Lam: Ah. I'm not going to answer it here. I am going to say everybody has to read the excellent editorial by Dr Granger from Duke University and Dr Mahaffey from Stanford University School of Medicine. But what I will tell you is their concluding sentences. They said, "This report provides evidence that Dapagliflozin appears to reduce atrial fibrillation events in patients with diabetes and coronary disease and multiple risk factors. It also raises the issue of how to determine when effects on a secondary outcome, particularly one collected without the rigor of systematic collection using perspective definitions and case report forms, whether or not these are reliable." So must read.

Dr Greg Hundley: Absolutely. Carolyn, my next study comes and evaluates arrhythmogenic right ventricular cardiomyopathy and is really investigating the concept of auto immunity, looking at associations of circulating anti heart and anti intercalated disc auto antibodies with disease severity and family history. The paper comes from Professor Alida Caforio from the University of Padova. Again, looking at the role of auto antibodies in patients with ARVC. An interesting topic.

Dr Carolyn Lam: Yeah, that's really novel. What did they find?

Dr Greg Hundley: They investigated ARVC pro bands, so those that sort of started with the disease process in a family and noted an increased frequency of serum organ specific anti heart autoantibodies and anti-intercalated disc autoantibodies in a sizeable arrhythmogenic RVC cohort as compared to controls. They found that positive AHA status.

Dr Carolyn Lam: Anti-heart antibodies.

Dr Greg Hundley: Yep. Was associated with lower left ventricular ejection fraction, a higher frequency of cardiac symptoms and implantable cardioverter defibrillator implantation. Positive AIDA was associated with lower ejection fractions in both the right and the left ventricle.

Dr Carolyn Lam: AIDA being the anti-intercalated disc auto antibodies. Wow. That is interesting. But what are the clinical implications?

Dr Greg Hundley: Well, the presence of both these organ specific AHA and AIDA antibodies provides evidence of autoimmunity in the majority, so 85% of familiar, and almost half, 45%, of sporadic ARVC. In programs and in effective relatives, these antibodies were associated with the disease severity features. So really a link with this auto immunity and ARVC.

Dr Carolyn Lam: Yeah. I never thought of ARVC as an autoimmune disease. Very interesting. But let me also tell you what else is in this week's issue. There are letters to the editors, one from Dr Kaski regarding the mag STEMI randomized control trial questioning whether improving coronary vasal motion can be equated to restoring patient's cardiovascular health. Interestingly with a letter in response from Dr Sabatine. There's also a research letter by Dr Alahmad on the cardiovascular mortality and exposure to heat in an inherently hot region and where they were was Kuwait. They also drew some implications for climate change. Very interesting piece. There's also an ECG challenged by Dr Verma describing conduction abnormalities and ischemic cardiomyopathy in an 84-year-old man.

Dr Greg Hundley: Very nice. Carolyn, in the mailbag, there's a nice research letter from Dr Nicholas Leeper from Stanford University School of Medicine. It's entitled “The 9p21 locus promotes calcific atherosclerosis.” Our own Josh Beckman has an on my mind piece regarding “The Big Mac Attack on Peripheral Arterial Disease.”

Dr Carolyn Lam: I love that. I just love the titles Josh comes up with.

Dr Greg Hundley: Then finally Bridget Kuehn has a very nice sort of correspondence on Cardiovascular News regarding cardiac imaging on the cusp of artificial intelligence. What a revolution we have ahead, Carolyn, and I know that's a topic that's true to your heart.

Dr Carolyn Lam: It is. I loved her paper.

Dr Greg Hundley: Okay. Carolyn, how about we get onto that feature article? I'm waiting to hear about the cost effectiveness of tafamidis.

Dr Carolyn Lam: Me too.

Dr Greg Hundley: Well listeners, we have got a great discussion for our feature publication today and we have Dr Dhruv Kazi from Beth Israel Deaconess in Boston and our own associate editor, Dr Justin Ezekowitz from University of Alberta. Well, as we get started, Kazi, can you tell us a little bit what was the hypothesis that you wanted to test with this study and maybe even before that a little bit of background with transthyretin amyloid and tafamidis?

Dr Dhruv Kazi: Yeah. Transthyretin amyloidosis is a subgroup of patients who present with heart failure with preserved ejection fraction, which we know is a heterogeneous condition that has been pretty resilient to effective guideline directed therapies over the past decade. It's a subgroup of patients generally presenting in their 70s with slowly declining quality of life and a median survival of about three years. It hadn't had an effective therapy before and so when tafamidis, which is a stabilizer of transthyretin and prevents its deposition in the myocardium, was developed and tested in a randomized clinical trial that showed an improvement in survival, a reduction in heart failure hospitalizations and a slowing of decline and quality of life. It was viewed as a really big win for the heart failure community.

What came as a surprise though is the pricing. It was launched in 2019 at $225,000 a year. We set out to ask, given that this is a severe disease without alternative treatments, is this price tag generating enough value? Is this a cost-effective therapy? The background here again is that oncologic therapies have had a long history of very high prices for rare diseases and severe diseases. But this is the first time we're seeing this in cardiology. Can we think more broadly about how we're going to tackle this issue? Not just for tafamidis but also for other drugs that come down the pipe.

Dr Greg Hundley: Wow. $225,000 per year. Tell us what was your study design, and how did you go about evaluating this issue?

Dr Dhruv Kazi: We started off with the one phase three trial of the drug that has been published and simulated in a mathematical model the population that would be eligible for this therapy, reproduced the events, heart failure hospitalizations, debts, quality of life that were seen in the trial for the first three years, and then extrapolated beyond the trial based on what we know about HFpEF and what we know about transthyretin amyloidosis. It's a mathematical model that first reproduces what was seen in the trial and then extrapolates beyond what we think is the best guess of what happens to these patients. We tested a variety of scenarios whether the drug continues to be effective, whether the effectiveness declines over time or the effectiveness ceases immediately after three years.

Dr Greg Hundley: What did you find?

Dr Dhruv Kazi: What we found was interesting and it surprised us a little bit, which is that in the base case, which is assuming that the drug stays effective beyond three years, the drug is actually very effective in the traditional sense. It added 1.3 quality adjusted life years. For context here, this is about twice the effect size you expect to see with Entresto, and the HFpEF patients. So here's a drug that we've accepted and HFpEF has part of guideline directed medical therapy. Tafamidis in that best-case scenario is about twice as effective, but it is not cost effective. Because you're paying $225,000 for every year that the patient is on the medication, its incremental cost effectiveness ratio compared with usual care was $880,000, so well above what we would consider value for money. That's the best-case scenario assuming that the drug is permanently effective, if the drug's effect wanes over time, which is very likely as these patients get older and sicker, then the drug gets even less economically attractive.

Dr Greg Hundley: You've pointed out in your article, if you had 120,000 transthyretin patients in the United States, that would translate to how many dollars?

Dr Dhruv Kazi: We estimate that if all of those 120,000 patients received tafamidis, the healthcare spending would go up by $32 billion a year and most of it is towards the drug. But the caveat is that we think 120,000 patients in the US is a very conservative number because the diagnostic technology for amyloid cardiomyopathy has improved substantially over the last five years so that we no longer need biopsies. We can use nuclear scans to diagnose the disease and we have pretty good to genetic testing to identify the genetic variant of the disease. We think that number is probably closer to 200,000 or even higher because the healthcare expenditure is almost entirely driven by drug costs. The more patients we diagnosed, the bigger the budget's impact on healthcare spending.

Dr Greg Hundley: Oh my. Well Justin, for our listeners, Justin resides in Canada. Justin, what do we do with these results? I mean this is quite a sticker shock for probably an important therapy for this patient population.

Dr Justin Ezekowitz: Greg, it's a great issue and Kazi, thank you very much for this terrific, easily understandable manuscript that I think everybody should read as it's very well written and easy to understand for us non-health economists. The sticker shock is a bit of a tricky one because we always want to do what's best for our patients. When we look at that budget impact analysis, the challenge is what do we think internationally? The US is critical in terms of understanding this, but then for the rest of the world, there's certainly almost no willingness to pay at this threshold and with an uncertain incidence of amyloidosis globally, but also within the US and Canada and the difficult in diagnosis already, I think we're going to have to realize what can we do for our patients and who benefits the most with this drug given its importance and its efficacy?

Kazi, you mentioned another thing which I think is critical is what happens after 30 months if the effect wanes and where does that take us for the impact on cost and effectiveness over time but also the budget impact analysis? Because the second drug or third drug may very well come along that may fill that niche.

Dr Dhruv Kazi: Justin, that's a really good question. I mean the study only goes to 30 months and that's the only one randomized trial for tafamidis that we're working off of. So there's substantial uncertainty about what happens to this drug beyond 30 months. It's reasonable to assume that some of the effect persists, that as patients get older, get sicker, that effectiveness will wane over time. Which ties very closely to the cost effectiveness. So if the patients continue to take the drug but it's not as effective as you can imagine, it becomes less cost effective.

This also has implications for other drugs coming down the pike, which may or may not be more effective than tafamidis. They may or may not be tested head to head with tafamidis. Physicians are going to be left with the question, very clinically relevant question, of which drug to start with, how do you switch on them the next generation or more expensive drugs that come down the pike? We'll have to rely on both real-world evidence and to some extent mathematical modeling to use our best judgment on developing a treatment strategy for these patients. But rest assured that our current regulatory framework means that the drugs coming down in the future will be more expensive than tafamidis and hence, this is a good time to have the conversation about cost effectiveness and our willingness to pay for innovation.

Dr Greg Hundley: What needs to happen next to help either lower cost or develop some sort of competition in the treatment of this disease to lower the cost?

Dr Dhruv Kazi: I can take a stab at that. Greg, I think the findings of this particular drug in transthyretin amyloidosis is illustrative of the challenges that lie ahead. I think there are clinical research and policy implications. As clinicians, it's really important for us to know that this high cost of the drug is not a theoretical challenge. It's a practical challenge for our patients. The majority of these patients are going to be on Medicare part D. We estimate that the out of pocket costs is going to be in the range of $8,000 to $9,000 a year even with Medicare part D, which is a big amount of money for our fixed income seniors. I encourage our clinicians to have this conversation about out-of-pocket costs with patients, not just when you start the therapy but throughout the year. We know that the Medicare part D copays change over the course of the year based on where they are in the insurance plan.

Having this conversation may help preclude costs related non-adherence. We might be able to identify patients early or at risk, put them into patient support programs or switch them to alternate therapies that may not be as effective but at least are likely to offer the patient some support.

From a research perspective, we really need to figure out what subgroup of patients are more likely to benefit. Let's say we have 200,000 patients with transthyretin amyloidosis in the US. We need more research, and the company is not going to be vested in doing this research, it's going to have to be NIH funded research to identify subgroups of patients who benefit most from this drug, both in the short term and over the long term.

From a policy perspective, what this drug pricing issue is telling us is that we provided incentives for companies to innovate in the rare disease orphan drug program. These incentives are working. More than half of the drugs that are coming out now or have in the past year are under this rare disease umbrella. But these drugs, once they're approved, are super expensive.

We need to figure out a regulatory framework where we continue to incentivize innovation for rare diseases for orphan drugs, but at the same time tie those incentives to the final pricing to ensure that the patients get access to the drug and not just the wealthy patients who can afford the copays, but all patients who would benefit from the drug.

One of the things that comes to mind as clinicians and researchers is that particularly in cardiology, we are obsessed with innovating, with regards to new molecules and new technology. I would like us as a community to focus not just on molecules but also on markets because the innovation is not meaningful if our patients cannot have access to them. This year being the presidential election year, we're going to hear a lot about drug pricing. What I hope that this example shines a light on is that drug pricing is complicated and trying to figure out the right framework to incentivize innovation while it's still ensuring access is going to take thoughtful interventions, regulatory interventions, and clinicians should very much be a part of that process.

Dr Greg Hundley: Well listeners, we've heard a wonderful discussion here highlighting a new therapy for a disease process that's being increasingly diagnosed with our aging population and new technologies, magnetic resonance, echocardiography that identify this condition. But then how are we going to afford some of the therapies that are moving forward and design a system that emphasizes not only scientific discovery, but cost effectiveness?

We want to thank Dr Dhruv Kazi from Beth Israel Deaconess and also Justin Ezekowitz from the University of Alberta. We hope you have a great week and look forward to speaking with you next week. This program is copyright the American Heart Association 2020.