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 of Circulation on the Run. I'm Dr Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore.
Dr Greg Hundley: And I am Greg Hundley, also associate editor from VCU Health Systems in Richmond, Virginia.
Dr Carolyn Lam: So, have you ever wondered in patients with atrial fibrillation and stable coronary artery disease beyond a year of coronary stenting, can you safely just continue on oral anticoagulation without antiplatelet therapy? Well, if you've ever wondered that ... I sure have. I'm sure you have too, Greg. Our feature paper this week does discuss this, so you have to stay tuned. But for now, Greg, what are your picks from this week's issue?
Dr Greg Hundley: I've got a couple to discuss. The first is Patrick Hsieh from Taipei, Taiwan, and really is evaluating the gut microbiota and how that affects cardiac repair after myocardial infarction. I mean, who would've thought to chase an idea like this? But what this investigative team did is they had mice, so this was a basic science experiment, and they treated them seven days prior to ligation of their left anterior descending artery that would induce a myocardial infarction. They treated them seven days prior with ampicillin, metronidazole, neomycin, and vancomycin. What were they trying to do? Totally obliterate any bacterial load within their GI system. Then, they ligated that coronary artery, and at 21 days, they looked at histopathologically what was happening.
And you know what they found? Those where they wiped out the bacterial load, they had increased cardiovascular events. And importantly, myocardial rupture was very high in this group of mice. Also those mice, they had reduced heart rate, and mechanistically what had occurred is there was a reduction in our immune monocytes that were trying to infiltrate the peri-infarct. They weren't there. They were not in those peri-infarct zones. And so, the thought here is that removal of the favorable microbiota in the gut can actually be harmful in the setting of myocardial infarction.
Dr Carolyn Lam: Fascinating. So, microbiome as our pals. But wait a minute. I mean, how can you say it's from elimination of the microbiome versus some kind of effect of the antibiotics itself?
Dr Greg Hundley: Yeah, that's a great question, Carolyn. The way they did this is they took another group of animals, and they supplemented them with lactobacillus probiotic, like the stuff we get in the grocery store. And those animals, they did not suffer any of the adverse cardiovascular effects. So, it really points to an important role of our gut microbiota. You know, and what do they do? They basically ferment these carbohydrates that we ingest, and produce short chain fatty acids that are a substrate for these mononuclear cells to help infiltrate those infarct zones. So, really exciting basic science question that this group examined.
Dr Carolyn Lam: I love that you picked a basic science paper, and I love that you made even me understand it so well. Okay, but what I have is a clinical trial. So, it's the REDUCE-MVI trial, which is the first randomized trial comparing maintenance treatment with ticagrelor or prasugrel after a primary PCI. So, this is from Dr van Royen and colleagues. They're from Radboud University Medical Center in the Netherlands. Basically, they figured that despite successful restoration of epicardial vessel patency with primary PCI, coronary microvascular injury does occur in a large proportion of STEMI patients, and of course, adversely affects outcomes. Now, ticagrelor has been reported to increase plasma adenosine levels, which may have a protective effect on the microcirculation. So, the authors randomize 110 STEMI patients following revascularization to maintenance therapy with ticagrelor versus prasugrel, with the primary outcome being microvascular injury at one month as determined by the index of microcirculatory resistance in the infarct related artery.
What they found was that there was no difference in the extent of microvascular injury and in the extent of infarct size by cardiac MRI at one month after the primary PCI. The attributed pleiotropic benefits of ticagrelor through the adenosine metabolism pathway actually could not be confirmed in the STEMI population, as plasma adenosine levels were actually not increased in the patients treated with ticagrelor.
Dr Greg Hundley: So, what does this mean for the use of adenosine and its role?
Dr Carolyn Lam: I suppose you're also asking, you know, is the adenosine hypothesis really out here? This is a study that really suggests we have to question it, but there are some limitations that we perhaps should keep in mind when we think about this. So first, before primary PCI, all patients were loaded with ticagrelor because this was standard of care in the participating centers. That, of course, could have modified microvascular injury already at the index event. Now, a second important thing is that the study may have been underpowered. There was a greater than anticipated variability in that primary outcome of index on microcirculatory resistance.
The relatively low rates of risk factors, the small infarct size, the preserved ejection fraction could all have influenced this IMR values, as well as the potential effects of the pharmacological intervention. And furthermore, the natural recovery of microvascular dysfunction over time may have diluted the positive effects. And of course, selection bias is inevitable in a trial. And so, you know, although this really questions the adenosine hypothesis, there are still caveats to these results.
Dr Greg Hundley: Very good. So, Carolyn, I've got another study to sort of go over, and this is from Dan Modin from the University of Copenhagen. And it's really addressing this issue. We all in the fall, do we all get our flu shots? And could that be helpful in patients with heart failure? You know, the ACC, the AHA, and the ESC all suggest flu shots, but there's actually no guideline to recommend. So, what did these investigators do? They looked in Denmark, and from the period of January of 2003 to June of 2015, they identified 134,048 subjects. And they looked at the vaccination status for those with a diagnosis of heart failure that were greater than 18 years in age. 55% percent of these were men. And then, they also looked at ICD-10 codes for cardiovascular events.
Now, they examine the dates of when you had your vaccination, how frequently, what were your comorbidities cardiovascular-wise, medication use, etc. And what they observed is that those individuals that had more than one vaccination ... So, basically annual vaccinations for a three year period, they had an 18% reduction in all death, and a 19% reduction in cardiovascular death.
Dr Carolyn Lam: So, is this all heart failure patients? Are there specific subgroups that we should be targeting?
Dr Greg Hundley: At our institution, they really get on us. If we don't have our flu shots in September, I mean, they threaten to withhold everything, or maybe October. Well, interesting that you asked that question. Those individuals that had flu shots in the September to October window did much better than those individuals that had their vaccination November, December, or actually later in January. And the second group that benefited were the individuals that actually had annual vaccinations. So, if periodically you say, "Oh, I'm going to get it this year, but then I'm not going to get it two years from now." Not so good. It was those individuals that had those vaccinations annually.
Dr Carolyn Lam: You know, Greg, it's making me question too, because here I am in a tropical island. We actually don't have seasons. So, what does that mean for us? That's one thing. And then, do we need even randomized trials now?
Dr Greg Hundley: Yeah, I think you're right there, Carolyn, because first of all, you know the investigators targeted this because 50% of heart failure exacerbations are actually triggered by some sort of respiratory infection. So, that was kind of the thought behind this. But we do have to be careful about looking at this longitudinal data and making predictions or developing guidelines. A couple of reasons why. It could be that those that come in for annual vaccinations at the time points, well, maybe they also come in for more frequent heart failure visits with their doctor. So, it's not cause and effect.
And in fact, there was another study, Get with the Guidelines heart failure study, and it actually showed no association. So, more work really needs to be done in this area. And just to point out quickly, there is a current randomized trial going on called Invested, and it's looking at different types of vaccinations, trivalent versus quadrivalent. They're underway in those with heart failure. And so, there's a lot more work in this area. But it was interesting getting it that old "get your flu shot," and it looks like at least longitudinally in cohort studies could be beneficial. And if you are going to do it, do it every year and get that September, October. So, Carolyn, what about your next paper?
Dr Carolyn Lam: So, Greg, my second paper is another trial. It's the radio sound hypertension trial, this time focusing on renal denervation. In fact, it's the first trial to compare three different techniques and technologies for catheter-based renal denervation. It's from Dr Lurz from Heart Center Leipzig in Germany. And what they did is, they randomized 120 patients with resistant hypertension to three arms. Either one, radiofrequency, renal denervation of the main renal arteries. Two, radiofrequency renal denervation of the main renal arteries and the side branches and accessories. Or three, an endovascular ultrasound-based renal denervation of the main renal artery. The primary endpoint was change in systolic daytime ambulatory blood pressure at three months. In the end, endovascular ultrasound-based renal denervation was the winner over radiofrequency ablation of the main arteries, with or without ablation of the side branches.
Dr Greg Hundley: Carolyn, does this mean that renal denervation is coming back? Are we going to actually start thinking about this as a viable option to treat those with longstanding hypertension?
Dr Carolyn Lam: Greg, this was exactly addressed by an editorialist, Dr Ram from UT Southwestern and Apollo Hospitals and Apollo Medical College in India. Beautiful editorial. Basically, even with the publication of these new data, it is difficult to predict whether renal denervation is firmly back on track. You see, some caveats should be mentioned, including that in this trial, only patients with large renal arteries were chosen for this study. And patient enrollment was rather selective.
For example, out of 1,884 patients screened, only 120 patients met the inclusion criteria. And then, importantly, in a few patients, the reduction in systolic blood pressure was really impressive, close to 40 millimeters mercury. But the majority of responders had a more modest effect, and in about 30%, there was no change in blood pressure.
So, one of the ultimate things we need to learn to do is to identify the so-called hyper-responders from the non-responders. So, lots more work needs to be done in renal denervation.
That brings us to a close of our little chat. Can't wait for our feature discussion coming right up.
Our feature paper today deals with a very important topic in a very frequently encountered group of patients. And they're the ones with concomitant stable coronary artery disease and atrial fibrillation. You see, these are patients at high risk of both ischemic and bleeding events, and therefore, it's critical to identify the right antithrombotic regimen with the optimal benefit ratio, since this is going to be lifelong therapy. Now, interestingly, despite recommendations in the guidelines and consensus documents, there has been no randomized controlled trial evaluating oral anticoagulation with and without antiplatelet therapy in patients with atrial fibrillation and stable coronary artery disease beyond one year of coronary stenting. I mean, Greg, I didn't even realize that we didn't have a randomized control trial. Did you?
Dr Greg Hundley: Absolutely, Carolyn. And, you know, this is an important issue, because we have a lot of patients coming to the cath lab that have atrial fibrillation, and what is going to be the recommended anticoagulant and antiplatelet combination? And so, it's really time for a randomized trial.
Dr Carolyn Lam: I know, and luckily for us, that's exactly what this issue's feature paper does. And I'm so pleased to welcome to the show Dr Satoshi Shizuta from Kyoto University Graduate School of Medicine, Japan, as well as associate editor Dr Shinya Goto from Tokai University in Japan. We're so proud to be publishing the OAC-ALONE trial, even though we understand it was a difficult trial. Tell us, what were the results?
Dr Satoshi Shizuta: As you know, the results were somewhat inconclusive because of pretty much a combination of patient enrollment. Initially, we scheduled to enroll 2,000 patients during 12 months, but patient enrollment speed was extremely slow, much slower than expected. So, we extended the patient enrollment period from 12 months to 38 months. But finally, we could only enroll 696 patients, about one-third of the initially planned patients. The result was around 50% rate of primary end point during 2.5 years of follow up. And the hazard ratio of [inaudible 00:15:01] strategy, as compared with OAC plus APT was 1.16 with a 95 confidence interval of 0.79 to 1.72.
So, in conclusion, our study failed to establish no inferiority of OAC-ALONE to combination therapy of OAC plus antiplatelet therapy in patients with AF and stable coronary artery disease beyond one year after stenting in terms of primary endpoint of death, MI, or stroke. So, this study was underpowered and inconclusive. So, future larger studies require to establish the optimal antithrombotic regimen in this same patient population.
Dr Carolyn Lam: Thanks so much. Shinya, you've been thinking about this, too, and the performance of such a difficult trial. Did you have anything to add or to ask?
Dr Shinya Goto: So, first of all, I would to congratulate Satoshi and the group. They have completed a very interesting randomizing trial. As Greg mentioned, there is two kind of patient who lead to coronary artery disease and atrial fibrillation, especially after, you know, one year after stenting. So, taking a look at coronary artery disease with atrial fibrillation, we don't have the established standard of care yet. So, Satoshi know, it is a long-time study. So, I understand the rich colored nature of the patient in this kind of trial. So, what is the most difficult point increased to encourage the patient in this long-term trial?
Dr Satoshi Shizuta: We think that difficulty reflects substantial reluctance of most cardiologists to withdraw antiplatelet therapy, single antiplatelet therapy from stented patients, even the patients treated with oral anticoagulation for atrial fibrillation. So, that is the most important point.
Dr Shinya Goto: You have already showed in this paper myocardial infarction recurrence of stents thrombosis. Not a huge problem in this kind of patient population, you know? Stroke is a bigger problem, mortality, not including cardiovascular is also the problem. So, you have suggested, you have a strong kind of mind, is it? And single antiplatelet therapy necessary after stenting. Your results are underpowered but still suggest how always you know would be enough in stable CAD patients with atrial fibrillation.
I would congratulate you again.
Dr Satoshi Shizuta: Thank you.
Dr Greg Hundley: Satoshi, I have a quick question. So, in the randomization process, how can you achieve the physicians managing the patients to administer the anticoagulant therapy to guideline levels, particularly when they are also prescribed antiplatelet therapy? I noticed that in the editorial on this manuscript that was a concern, and suggesting that in future studies that the therapy really be defined, and not so much open label administration at the discretion of the prescribing physician. What are your thoughts on that?
Dr Satoshi Shizuta: I agree with you, but in this kind of study, randomizing whether or not to withdraw a drug is very difficult to conduct. Financial support is limited, and in such situation, double blind placebo controlled trial is very difficult to conduct. As you know, several years ago, a loose trial was published in the Lancet. And also in the loose trial, the study design was open level, and also in the PCI and [inaudible 00:19:48], I think the study design was not blinded but open. In this paper figure two, our control level was set as a dependent based on the Japanese guidelines. In the Japanese guidelines, target IR was set as 1.6 to 2.6, a little bit lower than Western golden standard for elderly patients older than 50 years. And same 2.0 to 3.0 in patients younger than 70 years.
And in that criteria, as you can see, if you get 2A of paper, the therapeutic range was extremely high. 76% in the OAC-ALONE group, and also 73% in the OAC plus APD group. We can clearly understand that the intensity of oral anticoagulation was different between the two groups. Most of the OAC-ALONE group, OAC was controlled with ionine level higher than 2.0. On the other hand, in the OAC plus APD group, the ionine level was mostly controlled between 1.6 to 2.2 or .5 or so. So, this is a great big limitation of the study. But even in this limitation, the bleeding events, there was numerical excess in the OAC plus APD group. And, regarding the TEMI major bleeding, there was a trend toward increased major bleeding in the OAC plus APD group. If the intensity of OAC was the same, of course, I am convinced that even in this underpowered sample five, the major bleeding will be statistically higher in the OAC plus APD group.
Dr Carolyn Lam: Thank you so much Satoshi for really taking us under the hood, and showing us all the myriad of considerations that occurred to perform this trial.
This is Greg and Carolyn. Thank you for joining us on 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 it's editors. We're your co-hosts of Circulation on the Run and if you don't know what this show is about, well, you have to listen to the previous episodes in January please.
I'm Dr Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore.
Greg Hundley: I'm Greg Hundley from the Pauley Heart Center at VCU Health in Richmond, Virginia.
Dr Carolyn Lam: So Greg, before we pick up our coffees and begin discussing a couple of the paper, let's just tell everyone that this feature paper, they have to listen to because it is the results of the cardiac amyloidosis section, or sub-set of the APOLLO study. Have to listen to this one. But how about the other papers in today's issue Greg?
Greg Hundley: Right Carolyn, the first one I'm going to start with is from Alexander Fanaroff at Duke University and the DCRI. And basically, this particular paper was looking at the procedural volume and how that might affect outcomes with those that are performing PCI. So they divided the cohort into those individuals that had less than 50 PCIs per year, 50 to 100 and then greater than 100 PCIs per year. So, this is looking at our national cardiovascular data registry within the United States, and of course, as you know, that's linked to Medicare claims data for those that are over 65 years in age. So they had 723,644 PCIs performed by 8,936 operators. And the surprise in this study was that those low volume operators, less than 50 PCIs per year had a one year rate of 15.9% of MACE as opposed to those that were high volume operators that had 16.9% MACE rates. That was significant at a P value of .004.
Dr Carolyn Lam: Wait a minute, this seems different from prior reports. Are you saying that those with low volume operators actually had lower mortality?
Greg Hundley: Yeah, exactly. And you've pointed out something, cause previously what's been shown is that high volume operators have lower 30 day and in-hospital mortality rates. And that was actually confirmed in this study. But out of a year it was really the low volume operators in unadjusted results had lower rates of all MACE.
A very nice editorial by Dharam Kumbhani from UT Southwestern points out that high volume operators do tend to take on more serious cases, those with higher numbers of cardiovascular risk factors. And so, when they did adjustments and accounted for all those risk factors, actually the event rates were the same. Still though, they're the same. And so what could be going on? And the editorialist and also the authors of the paper point out, "Hey, maybe we shouldn't just be focusing on PCI volume per operator, but other quality metrics to look at outcomes. And so this really builds in to the whole quality discussion. Adherence to therapy with the patients in your health care system. What about operator longevity? An operator that may have been doing this for 10 years but has a lower volume, maybe that could come into play. So future studies I think, certainly all over the world in this field, this paper's going to direct us to focus more on other quality issues and not just procedural volume.
Dr Carolyn Lam: So, quality versus quantity. Interesting.
Well switching gears to a paper that I thought was nice, it is from Dr Lubitz from Massachusetts General Hospital in Boston and colleagues, and they sought to answer the question of whether refining a phenotypic classification of heart failure would facilitate genetic discovery. So, to do that, they defined all cause heart failure among almost 500,000 participants in the UK bio-bank and performed a GWAS study and then later refined the heart failure phenotype by classifying individuals with left ventricular dysfunction but without coronary artery disease as having nonischemic cardiomyopathy and then repeated the GWAS. And basically they found that the GWAS in the all cause heart failure yielded multiple genetic signals for known heart failure risk factors, such as coronary artery disease and atrial fibrillation.
However, after refining the heart failure phenotype to a nonischemic cardiomyopathy sub-set, this enhanced the detection of genetic loci associated with dilated cardiomyopathy, which appeared to operate independent of the traditional heart failure risk factors. So that was pretty interesting.
Greg Hundley: So where do we go from here with that Carolyn? I mean, what is this telling us and how are we going to move forward with this information?
Dr Carolyn Lam: I think the clinical implications are first that common genetic variants associated with both clinical and sub-clinical heart failure, because they looked at left ventricular dysfunction, these genetic variants may be leveraged to improve heart failure risk prediction and prevention. But obviously future studies are warranted to investigate the prognostic and therapeutic implications of these findings.
Greg Hundley: Very good. Well I'm going to take us back into the cath lab again and we're going to address fractional flow reserve. And remember, typically, we get fractional flow reserve measures using guide wires, and that's kind of a tough thing to do sometimes in terms of adding links to the procedure, etc. So what these investigators did, they had 10 centers in the United States, Europe and Israel. And this was William Fearon from Stanford University who did this study. And they looked at 301 subjects and they had 319 evaluable vessels. Now what did they compare? They looked at guide wire derived fractional flow reserve versus angiographic derived. Simply, just when you're doing the injections, looking at how quickly that contrast flows down the coronary arteries.
And so, in this study the mean fractional flow reserve value was 0.81 and 43% of the vessels they studied had an FFR less than or equal to that magic number of 0.8. Interestingly, the angiographic obtained FFR measures were 94% sensitive and 91% specific for identifying the guide wire derived FFR. That's really incredible. And importantly, the accuracy of this contrast measure was 87% for FFR values between 0.75 and 0.85, that magical threshold.
Dr Carolyn Lam: Well that is impressive, suggesting that we don't need guide wires. I mean, is that true for all patients? All vessels?
Greg Hundley: Right, so that's sort of the kick here, this is really interesting new data but let's look at the patients that they studied. First of all, they were relatively stable I would say. They had either angina or maybe even unstable angina and non-ST elevation MIs. But no ST elevation MIs. The average stenosis by angiography that they looked at was about 63% and then, very importantly, you have to look at the exclusion criteria. So things that, other conditions within the heart that are going to impact FFR were excluded. So, all their patients had an EF greater than 45%. Nobody had a CABG. Nobody had a chronic total occlusion. Nobody had a heart transplant, aortic stenosis, no heart valve surgery, no left main. It couldn't have had a recent stent within 12 months. It couldn't have had severe diffused disease, no collaterals, no in-stent thrombosis or stenosis. So this technique I think could be useful when you've got that patient perhaps with stable angina, single vessel disease, stenosis severity of 50 to 60% and none of these other conditions, preserved EF etc. But for many of the patients that we send to the cath lab, this technique, we still need a little bit more development. We don't know its utility. You've got another paper?
Dr Carolyn Lam: I've got another few papers because I'm going to drag you out of the cath lab right now and into the ICU. And we're talking about cardiogenic shock and it's really nice that we have these three papers in today's issue. One's an original paper and two are On my Mind articles. Now the original paper talks about the randomized shock cool trial. This is from Dr Thiele from the heart center Leipzig in University Hospital in Germany. And it is an un-blinded, randomized trial of 40 patients with cardiogenic shock undergoing primary percutaneous coronary intervention. And without a classical indication from mild therapeutic hypothermia, but randomized one-to-one to mild therapeutic hypothermia for 24 hours versus control. And basically the mild therapeutic hypothermia did not show a substantial beneficial effect on the primary outcome of cardiac power index at 24 hours or on any other of the hemodynamic parameters. And there was also no difference in the short and long term outcomes. So a neutral trial.
But taking a step back and just talking about these patients with cardiogenic shock and all the different ways that we have now to keep them alive, I really want to highlight these two On My Mind papers. One is by Drs Gill, Grunau and MacRedmond from University of British Columbia. And they really talk about the need to define limits for extracorporeal cardiopulmonary resuscitation. In a very similar vein, Drs Mulaikal, Nakagawa and Prager from Columbia University also wrote a beautiful piece on ECMO, ECMO as a bridge to no recovery. And when is enough enough? So really, really interesting conversations and discussions regarding what is death, when do we have to put a time limit perhaps to these therapies? And yet not limit the potential life-saving effects of these. I really strongly encourage our listeners to read these papers and also to stay tuned because coming right up, a very important paper on the APOLLO study in our feature discussion.
For today's feature paper we're discussing the results of a sub-study of the APOLLO study. Now this deals with cardiac amyloidosis, a super, super hot subject. And we have super, super hot guests today on the show. The first our corresponding author, doctor Scott Solomon from Brigham and Women's Hospital as well as our associate editor doctor Justin Ezekowitz. Welcome both, and let's just plunge straight into it. So Scott, tell us, tell us about this APOLLO sub-study.
Scott Solomon: APOLLO is a study of patients with hereditary transthyretin amyloidosis and, as you know, that hereditary transthyretin amyloidosis is an inherited disease caused by mutations of the transthyretin gene and these mutations cause the transthyretin protein to misfold and then accumulate as amyloid fibrils which go to the nerves and go to the heart. And we know that this can cause severe polyneuropathy and cardiomyopathy, partly depending on which mutation the patients have. And we, as cardiologists, are aware that when amyloid infiltrates the heart it can increase cardiac wall thickness, it can cause increase in chamber stiffness, it can result in severe diastolic dysfunction and these patients, often with cardiac involvement of amyloid, have a really markedly reduced life-span and really poor quality of life.
The APOLLO study was a study of a new agent that is designed to reduce transthyretin, it's a transthyretin knock-down agent. It's basically an RNAi therapeutic, it basically is a small, interfering RNA that basically blocks the production of transthyretin and this is one of several approaches that are currently being considered for amyloid disease. And APOLLO is primarily designed as a study to look at neuropathy. The primary end-point was a neurologic scale to look at neuropathy, but it was also designed to secondarily look at some cardiac end-points, especially in the patients who were felt to have cardiac involvement.
Dr Carolyn Lam: Cool. And so your current paper deals with that cardiac amyloidosis sub-set, but it was pre-specified, it was planned, right?
Scott Solomon: Yeah, it was a pre-specified sub-group. In fact, what we did is we actually did echocardiograms on everybody in the study and then defined a pre-specified cardiac sub-population that was comprised of patients who had a very high likelihood of having cardiac amyloid involvement, and so this was patients who had a baseline left ventricular wall thickness of 13mm or greater and no history of either aortic valve disease or hypertension. And so this was a group that we thought most likely had evidence of cardiac involvement. And just so it's clear, we did echocardiography on everybody in the study and in this paper we reported in both everybody and in the pre-specified cardiac sub-population. So we looked a number of things in these patients including various measures of cardiac structure function including wall thickness, left ventricular mass, ejection fraction, cardiac output, atrial size, volumes and myocardial strain which, as you know, has been particularly useful in assessment of patients with amyloidosis. And we also looked at reduction or improvement in Anti-proBNP which, as you know, is a very good measure of the severity of heart failure in patients.
And so, of the 225 patients who enrolled overall in the APOLLO study, 126 were part of this pre-specified cardiac sub-population. And in this group of patients, we've observed a reduction in left ventricular wall thickness of about a millimeter. And this was statistically significant in the patients who were treated with patisiran compared with placebo. We also saw an improvement in global longitudinal strain and improvement of cardiac output and an increase of left ventricular end-diastolic volume. In this case an increase in end-diastolic volume is actually a good thing because these patients often start out with smaller end-diastolic volumes because of the increased wall thickness. Those improvements in echocardiography were really paralleled by dramatic improvements in Anti-proBNP and we started out with patients with abnormal Anti-proBNPs in the range of about 800. These were significantly reduced, highly significantly reduced with a P value of about seven times 10 to minus eighth at both nine and 18 months, so pretty dramatic relative reduction in Anti-proBNP in the patisiran group compared to placebo.
Dr Carolyn Lam: Super exciting, and it really adds to mounting evidence isn't it? That we're sort of reaching a really effective treatment for these patients and who knows how common they are. But Justin, you've been thinking a lot about this, what are your thoughts?
Justin Ezekowitz: This is a terrific paper, and this is a groundbreaking therapy. Scott, this really has something for everybody, for example functional Anti-proBNP and echocardiographic measures of improvement and also less deterioration which I think is also holding it in its tracks. The question is, if you have 126 patients in the cardiac sub-group, whether or not this is really prime for clinical integration, as to start using this therapy broadly or do we need to really broaden the scope and do larger outcome studies with this therapy for these patients, recognizing some of the gaps in any clinical trial design and implementation. So what are your thoughts on that?
Scott Solomon: First of all, it's important to remember that the APOLLO study was designed primarily to look at the neurologic outcomes, not the cardiac outcomes. The cardiac outcomes were technically considered exploratory and, in fact, although really pretty impressive in this group, this wasn't really how the study was designed. And so the current indication for this particular therapy. Patisiran is for the improvement in the neurologic outcomes, not for the cardiac. So I think that there will need to be additional studies that will look more specifically at the cardiac effects, although I think these are among the most impressive findings we've seen with any agent that is interfering with transthyretin. And just to put this in context, there are a variety of ways in which amyloid can be affected and one of the other approaches to this disease has been not to reduce the production of transthyretin but to stabilize transthyretin.
And you may be aware of the ATTRACT trial which was presented at ESC and published in the New England Journal, which was actually an outcomes trial in patients with cardiomyopathy secondary amyloid and they used a drug which is a TTR stabilizer and showed a significant reduction in cardiac events and mortality. And I think that in the context of that study, this is extremely exciting as well because it says that there are multiple potential approaches to affecting transthyretin and potentially improving outcomes in patients with cardiac amyloidosis. There are other approaches that also are being tested. In fact, another therapy that works in a similar way to patisiran is atersin which is an agulo nucleotide anti-sense molecule. And so, I think that it's such an exciting time now in this field because there almost certainly will be several different approaches to transthyretin amyloidosis.
So, I think, Justin, to succinctly answer your question I don't think we're quite ready yet with patisiran but stay tuned because there will be more trials for sure. The other thing that we have to realize is that this study was done in mutant or hereditary amyloidosis but there's a very broad group of patients out there with wild type amyloidosis and there's no reason to think that a therapy like this won't work there as well. So that has to be tested too.
Justin Ezekowitz: I think, Scott, that's a true way to put it. I think one of the other questions is the substantial difference between the trials and sub-groups of the trial between the three major therapies you just described about wild type versus hereditary. It does make you wonder if either one individual therapy or a combination of the therapies might give the right way to precisely manage these individuals according to their phenotype, neurologic status or cardiac status.
So, I maybe just want to draw you on one other point which is that you used global longitudinal strain as one of your outcomes and it sounds like, and from all the data we've seen, it looks like GLS will be the way to go for earlier phase two and other types of studies. What are your thoughts based on experience?
Scott Solomon: Well in general I'm a big fan of global longitudinal strain because I think it is, in many respects, more robust than our standard measures of cardiac function like ejection fraction, it's not volume dependent the way ejection fraction is. In particular in amyloid heart disease, as you know, global longitudinal strain can be quite abnormal and, interestingly, it can be quite abnormal in a very specific pattern. And patients with amyloid is typically sparing at the apex, so the apical strain is relatively normal compared to the strain at the base of the heart. And this is kind of interesting and we've certainly been looking at this as well in amyloid heart disease but I agree that this global longitudinal strain as a measure of potential benefit for a therapy has a lot of potential.
Dr Carolyn Lam: You know, that's just so amazing. I just have one last question for both of you. Where do you think the field is going? Do you think it's going to be a race to treatment or a race to diagnosis? I shudder to think of the number of cases we're missing, what do you think Justin?
Justin Ezekowitz: Carolyn you just brought up a great point which is, one is our diagnostics need to improve and be broadly applicable and implementable in any health care system, so I think that race has to speed up and become more cost-effective and efficient to know who indeed we need to screen closer. That's point number one but number two is the therapies ... the race has to be focused around what will be the best way to treat patients rather than the cost-effectiveness initially, but then once we identify the three or four different agents that work with different groups and how you can combine them, then the consideration has to be how we can apply these more broadly to the groups that really haven't had a therapy that has had a meaningful impact trajectory.
Dr Carolyn Lam: Scott, what do you think?
Scott Solomon: Well I would add that one of the most exciting things I think in this area, Carolyn, and this is going to interest you I think because of your own interests, is that there's probably a lot of amyloid out there that we don't know about. Especially in these patients that we're currently calling heart failure with preserved ejection fraction. There's some data from Mayo clinic and from groups in Europe suggesting that 15 to 20% of patients with HFpEF, might actually have wild type transthyretin amyloid. And that means that we've got to get better at making this diagnosis, especially where our suspicions are high. Because we might all of sudden have a targeted therapy for some of these patients, so I think that's one area where things are really exciting. And then with respect to which of these therapies is going to be beneficial, I mean I think that we're still in the early stages, it's very possible as Justin said that even a combination of TTR stabilizers and knock-down agents are going to provide the best benefit. But I think we're going to see a lot of very interesting studies in the next several years in this field. It's really great to have a potential molecular target, and targeted therapy for a type of cardiomyopathy and I think this is one of the really few areas where we have that as this point. So I'm extremely excited.
Dr Carolyn Lam: Thank you so much for publishing your paper with us in Circulation.
Well audience you heard it right here on Circulation on the Run. Don't forget to tune in again next week.
This program is copyright American Heart Association 2019.
Dr Carolyn Lam: Hello. We're here at the American Heart Association meeting in Chicago where circulation has 19 simultaneous publications this year. And that is a huge increase from six in the past to 19, all thanks to the man next to me.
But first, let me introduce myself. I'm Dr Carolyn Lam. I'm associate editor from the National Heart Center and Duke National University of Singapore. I'm the voice you hear on 'Circulation On the Run'.
I'm so pleased to be here in person today with Dr Dharam Kumbhani. He's associate editor from UT Southwestern and he also leads the simultaneous publications for this journal. So big applause for this amazing bonanza this year.
Dr Dharam Kumbhani: Thank you.
Dr Carolyn Lam: Next to him, we have Dr Sana Al-Khatib and she's from the Duke University. And finally, Dr Gabriel Steg from University of Paris. Wow! Okay, we've got 19 papers to chat about. No, I'm just kidding. We're going to talk and focus on the seven simultaneous publications that were late-breaking science.
Why don't you start us off, Dharam. We will first start with the interventional trials, and there were three of them. I'd love you to chat about the first of them, but even before that, maybe, tell us what it's like to get a simultaneous publication. Because I think people underestimate the amount of work it takes to do that.
Dr Dharam Kumbhani: Thanks a lot, Carolyn. I think under Joe's leadership the whole space of simultaneous publications in late paying clinical science has really been a big endeavor for him and for the journal. We just have an amazing team that's able to work on this in very quick order. So, for the viewers, I think it's a very involved process, but it's a very gratifying process.
We work very closely among the associate editors, the senior editors, and then the circ staff, and we have very rapid turnaround time. So we owe a lot of gratitude to our reviewers who frequently will turn these reviews in within 48 hours. Our goal has been that we respond back with a decision usually within five to seven days. So it's been very gratifying.
Then it moves onto the next set of revisions, et cetera. But even among the papers that we are unable to accept for circulation, it's just a quick turnaround time for the authors so they haven't lost as much time and can potentially look elsewhere.
It's been a really gratifying process. It's been a great, great team effort. I appreciate everything you said, but really I don't deserve all that credit. It's been a great team effort.
Dr Carolyn Lam: No, it's been rumored there's a lot of lost sleep on your end, so thank you, thank you Dharam for this. And maybe you could open with the ISAR-TEST 4, that's been [crosstalk 00:02:47].
Dr Dharam Kumbhani: Yeah, well thank you. I think we had some really interesting interventional trials and Dr Steg will discuss a couple of them as well.
ISAR-TEST 4 was a very interesting trial. It is one of the first 10 trials that gets to the 10-year mark, so this is just the 10-year follow-up results of that. It was about a 2500 patient trial. It was done in Germany, multiple centers. Really they were trying to assess the space that they were trying to ... Or the knowledge gap that they were trying to fill was the durability of the bioabsorbable polymer stents.
Specifically, they were looking at a bioabsorbable polymer sirolimus-eluting stent, the Yukon stent, and then they compared that with durable polymer stents including Xience or the everolimus-eluting stent and then Cypher, which is no longer available in the U.S., but that's a permanent polymer sirolimus-eluting stent.
The primary results were published and presented a long time ago. There was really MACE events at one year and it showed non-inferiority for this bioabsorbable polymer stent back then. So, then they had, incredibly, 83% of the cohort that they were able to follow-up out of 10 years. And what they showed is that ... I don't want to necessarily get into the numbers and the details as much, but what they showed is that this bioabsorbable polymer sirolimus-eluting stent tended to have similar outcomes to Xience, which we accept as state of the art current generation stent, permanent polymer. And it did better than the Cypher stent, both in terms of MACE events and stent thrombosis.
So suggesting that, the big advance in the field for this is ... This is a long-term follow-up of the stent. It suggests that outcomes may be similar in this patient population. Although only 12% were really enrolled with an MI in this patient population. Most of them were stable or less sick ACS patients. And they show fairly good outcomes out of 10 years, comparable to Xience and better than Cypher.
I think it was interesting. Gabriel, what is your take [crosstalk 00:04:57].
Dr Gabriel Steg: I think it's important. There's been a tremendous interest in international community on trying to tease out which are the best types of stents and beyond brands, try to understand the type of stent, the coating, the drug that you put on it, whether the polymer is durable or not durable. I think these types of fairly well done, large randomized trials with long term flow are critical.
A lot of the focus in the interventional community originally was on lumen size, late loss, angiographic parameters short term. And now the field has matured, and we've moved to clinical outcomes, patient-oriented outcomes, long term follow-up. And it's important because we've learned from long term trials such as PROTECT that the result at one year may not predict what happens at five years, and sometimes you have surprises.
So, it's really important. We owe it to our patients because these are irretrievable devices. Once you've implanted them, they are there. We talked about Cypher being out of the market, but there are more than a million patients who walk every day on this plant with a Cypher in their coronary artery, so we better know what the long-term follow-up is.
Dr Dharam Kumbhani: Yeah, that's a great point.
Dr Carolyn Lam: Wow. And then thanks also for the discussion that allows me, as a noninterventionist, to realize ... It's hard to keep track of what's happening with all the different types of stents and polymers and so on. But could you then summarize for the field, does that mean that these biodegradable ones are now ... Do I sound ignorant when I say that? That they are now really in the game. Is that what it does?
Dr Dharam Kumbhani: This whole bioabsorbable field, there are nuances. So this really is testing a bioabsorbable polymer where -
Dr Carolyn Lam: Oh!
Dr Dharam Kumbhani: So, with every stent you have a stent, you have the polymer, and then you have the drug.
Dr Carolyn Lam: Thank you.
Dr Dharam Kumbhani: And so, the polymer and the drug go away, and then you're left behind with a bare metal stent. And that's this Yukon stent.
Dr Carolyn Lam: Got it.
Dr Dharam Kumbhani: The one that has been in the press a lot more is the bioabsorbable scaffold where the stent and the polymer and the drug, everything in theory should be gone at a certain period of time. So this is ... It's an important distinction though. Because I know that it's very confusion when you just say bioabsorbable and it's unclear if you're talking about the polymer or you're talking about the stent, itself. But this really was a bioabsorbable polymer issue, so you're left behind with a bare metal stent at the end of it.
Dr Carolyn Lam: Got it, crystal clear, and thank you. That's cool. That's super.
Dr Sana Al-Khatib: I agree, for an electrophysiologist too.
Dr Carolyn Lam: But now, let's go into the AMI field. There were two trials that really spoke to acute management patients coming in with an AMI and with cardiogenic shock, for example. Gabriel, could you tell us a little bit about the IABP-SHOCK II trial, as well as the really talked about a door-to-unload IMPELLA Trial.
Dr Gabriel Steg: The IABP II trial is a randomized trial looking at the benefit, or lack thereof, of intraaortic balloon pump in patients with cardiogenic shock and acute MI. It's been standard practice since the '60s to offer IABP pumping to patients with cardiogenic shocks and AMI.
So, literally more than a million patients have been implanted with IABP, but the reality is when we look at the randomized trial evidence of benefit there was none. They were very small trials, inconclusive, underpowered. Professor Thiele from Germany and his colleagues deserve enormous credit for having had the courage to really do what needed to be done. A proper randomized controlled trial, of course open label.
And what they found in IABP II, which they already reported a few years ago, was that there was no acute benefit of IABP on survival short term, or for that matter on many of the secondary clinical outcomes looked at in this trial. They subsequently reported one year mortality.
What they did here is they gathered follow-up on almost all of the cohort at more than six years. And they found that the long term survival is identical for patients who received an IABP and those who did not. So I think this nails the issue. But there's another thing we learn. The mortality at six years is staggering, it's close to 60%. And although a large fraction of the patients die in the first 30 days, you still have an additional 10% of patients who die between the first year and six years.
So there still remains a very sick patient population for whom we need to investigate new strategies. I don't think it's going to be necessarily mechanical. We have to think of all of the strategies we do to prevent and mitigate cardiogenic shock to build up. And that's gets us to the second trial that I'll talk to you about in a minute.
Dr Sana Al-Khatib: I have a quick question about this. Did they provide any information about modes of death in these patients?
Dr Gabriel Steg: Yes. They did capture information about that. Off the top of my head, I'm unable to provide information, but yes they did capture that. The German system allowed them to retrieve information about causes of death and it's a closed system. It's a national trial, so they were able to get enormous follow-up.
Dr Sana Al-Khatib: Because this information can help us inform what interventions are needed next.
Dr Gabriel Steg: Yes. That's really important.
Dr Dharam Kumbhani: To your point about ... You use a very interesting word, the last nail. That's actually how Dr Hochman addressed her editorial. She wrote a really nice editorial-
Dr Gabriel Steg: The leading expert in the field.
Dr Dharam Kumbhani: And so, I'm interested in your thoughts. The use of balloon pumps for shock, there's a discrepancy between the American guidelines and the European guidelines. Last year the European guidelines were updated. It is really such a practice changing guideline in that it now lists routine use of balloon pumps in cardiogenic shock-
Dr Gabriel Steg: Class III.
Dr Dharam Kumbhani: -as a class III indication. Going through training, that was all you had when someone came in with shock, you would throw in a balloon pump. So that's really quite a practice changing event.
Dr Gabriel Steg: Yeah. These investigators are embarking on new studies with ECMO and I think it's going to be fascinating to see whether ECMO, which also gets increasingly used worldwide, whether there is evidence to acutely support or not whether this is useful. I think they are doing the proper thing. They are doing the right thing, randomized trials. And we could commend them because these are really difficult trials.
Dr Carolyn Lam: Absolutely.
Dr Gabriel Steg: In the acute MI setting, shock patients, ECMO, IABP, that's really difficult. They are brave investigators, they are good investigators, and I think they provided the community with a clear answer.
Dr Carolyn Lam: And exactly the kind of papers that we like publishing at circulation, isn't it? Now what about the door-to-unload?
Dr Gabriel Steg: That is actually a good segue with door-to-unload because if we can't properly treat shock once it's there, can we do something to prevent shock? Can we do something to preserve myocardium? One of the experimental findings that is very clear is that if you unload experimental myocardial infarction, if you unload the left ventricle you reduce infarct size.
Dr Gabriel Steg: So, investigators have been trying to translate this experimental finding into the clinical arena using the Impella device. There's enormous interest, particularly in North America for Impella use in acute MI patients with larger infarcts with the idea that if you can unload the left ventricle, you might be able to mitigate the extent of the myocardial infarction, and therefore avoid cardiogenic shock and probably improve prognosis.
Although this is a very attractive theoretical concept, it still deserves to be tested. And so, if you want to test it you have to unload the ventricle as soon as possible, ideally before reperfusion, which means that you're going to have to delay reperfusion for the time of implanting the device and unloading the ventricle. And so what the investigators did in this trial is to study whether delaying proposedly by 30 minutes reperfusion, to unload the ventricle for 30 minutes prior to reperfusion, was feasible and reasonably safe.
It's a small trial. It's really a pilot trial. By no means does it test the proof of concept of the device or the theoretical issue, but it shows that it's feasible. There doesn't seem to be a massive increase in total time to reperfusion because just by change the group that was not delayed had a longer time to PCI, so eventually things are sort of evening out.
They looked at MRI size of infarcts at follow-up. There was no obvious difference, but of course it could still be tied to errors. We're not totally sure about this, but it certainly paves the way for doing a proper proof of concept randomized trial, testing unloading versus no unloading with a true control group. And I think that's what investigators are looking forward, but I understand there's immense interest for this concept in international community, particularly in the United States and I'm quite curious to see what this future trial will look like and what the results will be.
Dr Carolyn Lam: Yeah, indeed. Gabriel, I noticed you were very careful to frame it, to say what the trial was trying to address and what it wasn't. And there's been quite a bit of buzz after that.
Do you agree with everything Gabriel has said and what have you heard?
Dr Dharam Kumbhani: I think he was incredibly eloquent in outlining the premise of the trial and what it really showed. I think the one thing that ... And this was brought up in the very nice editorial by Dr Patel from Duke as well, is it would've been really nice to have a control arm which didn't have any unloading. Because these are not patients with shock, that just directly had primary PCI. And then comparing infarct size.
So, I think that was one of the pieces of information that would've been helpful to then put this in perspective. When you have an infarct size of 8% or 10%, how does that compare in the same patient population in their testing? You're absolutely right about the need to do difficult trials like this, where a lot of times it's just assumed to be true and is embraced in clinical practice.
As I gave the example about the balloon pump earlier, where as a Fellow you saw someone in shock and your reflex was to put in a balloon pump. And so, I think testing these very difficult patient scenarios, as well as just in terms of trial execution, it's amazing to have two trials on that.
Dr Gabriel Steg: If I may come back to this?
Dr Carolyn Lam: Yes.
Dr Gabriel Steg: It's funny because we've been using the IABP for years, thinking this is what we should do in shock. Now our German colleagues have proven that IABP doesn't work. So a lot of investigators have reverted, saying "Well, we should use Impella." But where is the evidence showing that Impella is beneficial?
Dr Dharam Kumbhani: That's right.
Dr Carolyn Lam: That's right.
Dr Gabriel Steg: We have none, so I think that's a trial that deserves to be done.
Dr Dharam Kumbhani: And ECMO. Yeah, exactly.
Dr Carolyn Lam: Yeah, ECMO. Exactly. And, you know, going back to door-to-unload, it's important to prove safety in order to go to the next step, which is exactly how you frame-
Dr Gabriel Steg: I think it shouldn't be over interpreted.
Dr Carolyn Lam: That's how it should be, exactly, received by the community. So that's great. Now let's switch gears a bit.
Sana, in EP world, the EP guided noninvasive radio ablation of VT. Fascinating stuff. What are your thoughts?
Dr Sana Al-Khatib: I absolutely agree, definitely. This was a phase two study that the authors did. They enrolled 19 patients, so it was a small study, but it was really helpful. Remember, there's a major clinical need there. These are patients who have an ICD, who have recurring ventricular tachycardia, that have been treated with at least one antiarrhythmic medication, at least one catheter ablation procedure, and then what do you do with those patients? This is actually a clinical scenario that comes up frequently and we absolutely need to be looking for more therapies for those patients.
So that's what that study was about, trying to explore new ways to treat these patients. To be able to do it noninvasively, I think is fascinating. That's what ... They enrolled these patients. Patients had to have failed these treatments, antiarrhythmic medications, prior catheter ablation, and they underwent noninvasive imaging to really localize the source of the ventricular tachycardia, where it's coming from, and then they subjected them to stereotactic body radiotherapy to ablate those sources of ventricular tachycardia.
And, of course, the results were fascinating because they showed on the effectiveness side that this seemed to be very effective because if you look at the reduction in the burden of ventricular tachycardia, and a couple of their patients actually had significant PVCs and PVC induced cardiomyopathy, there was a significant reduction in the rates of these arrhythmias in these patients with this intervention, which was great to see.
In fact, to be specific, about 94% of these patients, so 18 out of the 19, had significant benefit. And in about 89% of the patients there was more than 75% reduction in the arrhythmia. So these are actually really interesting findings, especially in a patient population where we really don't have other options. Now of course you're going to ask me about the safety. What are the safety concerns?
Of course, this was a primary endpoint for the authors. They did look at safety up to 90 days and they found that there were two significant adverse events that occurred in those 90 days. One was heart failure and one was pericarditis. The concern, of course, with radiation is what else can we expect especially if you follow the patients longer? So certainly we need more data. The authors acknowledged that beautifully and I think their intent is to launch a multi-center randomized clinical trial. I don't know if it will be randomized, but at least a multi-center clinical trial to see if they can replicate those findings. So that was very interesting to see.
Dr Carolyn Lam: Yeah it was. Thanks, that was really exciting.
So, some exciting trials in my world of cardiometabolic disease too, and I want to highlight two. The CARMELINA trial and the CAMELLIA-TIMI 61.
First the CARMELINA trial. This was a secondary analysis of CARMELINA and this was ... CARMELINA, if I can remind everyone, is a cardiovascular outcomes trial, randomizing about 7000 patients with type 2 diabetes and atherosclerotic cardiovascular disease, and/or chronic kidney disease. Randomizing them to the DPP-4 inhibitor linagliptin 5 mg a day versus placebo, following up for a median of about two years.
We know that type 2 diabetic patients are at risk of heart failure and there's always been a bit of a question mark when it comes to DPP-4 inhibitors and their risk for heart failure. And so this secondary analysis looks specifically at the hospitalization for heart failure and related events in CARMELINA. The important thing is that all these were prospectively centrally adjudicated events, and this was a pre-specified post hoc analysis.
And the summary of it all is that linagliptin was not associated with an increased risk of hospitalization for heart failure or the composite of cardiovascular death in hospitalization or the related outcomes. Importantly, the authors did also sensitivity analyses and interaction analyses to show that the results were consistent whether or not patients had a history of heart failure, which was in 27% of patients, regardless of the baseline ejection fraction that was measured within a year of starting the drug, and also regardless of renal function. So EGFR or urinary albumin to creatinine ratio.
This is really important because this trial adds to the growing perhaps understanding of DPP-4 inhibitor heart failure risk. The whole question mark actually came with SAVOR TIMI and that was saxagliptin. But since then there's been three other trials that have showed no heart failure risk. EXAMINE, TECOS, and now CARMELINA. So, an important addition and I think it should reassure us.
And then from diabetes and heart failure risk, which is always very hot, but now obesity. The CAMELLIA-TIMI 61 trial looked at renal outcomes in this trial. Now what was this trial? It was actually testing lorcaserin, and that is a selective serotonin 2C receptor agonist, in about 12,000 obese or overweight patients.
Basically, the primary results showed that it did not increase any ... It met it's CV safety outcomes with weight loss and so on. But this time they looked at renal outcomes. Because obesity has been known to be associated with hyperfiltration of the kidneys, you get albuminuria and it's apparently worsening of kidney disease. So what we need to know is pharmacological weight loss going to be associated with improved renal outcomes?
And basically, that is what CAMELLIA-TIMIA 61 showed. Their renal outcomes were new or persistent albuminuria and then the standard doubling of EGFR or end-stage renal failure, renal transplant or renal death. And that was improved by lorcaserin. Along with that, there was the anticipated reduction in weight, HbA1c, and BP. It does look like, from these late breaking results that we have another tool in our toolbox.
Dr Sana Al-Khatib: And for the clinicians out there, which patients should they be thinking to use this medication in? What kind of obesity are we talking about? At what point do you introduce that?
Dr Carolyn Lam: This is common garden, just defined by BMI that was above 27. And I don't think they're saying to use it in patients with renal dysfunction, but to sort of say to look and see whether weight loss also associates with renal function improvement, and it does. It's reassuring.
Dr Sana Al-Khatib: Yeah, okay.
Dr Carolyn Lam: And then ... Okay, let's round up with that last trial. A very interesting one because it's pragmatic mobile health and wellness. Tell us.
Dr Dharam Kumbhani: It's really a monumental effort. This is ... I'll be brief, but it's really a phenomenal trial from an epi standpoint and implementation standpoint. This is from India. It was coordinated by the Center for Chronic Disease Control and the Public Health Foundation of India where, as everyone knows, India is now the diabetes capital of the world and chronic diseases have very quickly overtaken other infectious causes as the number one cause of mortality and morbidity.
This was a big undertaking, really collaboration from three continents, but it was a community based plus a randomized trial. They had 40 community health centers and what they were trying to see is primarily for hypertension and diabetes. That if you implemented a structure and typically using this mWELLCARE tool, which is basically an electronic medical records storage facility and then it also has inbuilt clinical decision support.
And really for hypertension and diabetes management, but also, they had tobacco and alcohol screening, abuse screening, and also for depression. So what they really wanted to do ... A very ingenious endeavor and they try to see if doing this systematically on a clustered randomized fashion if that would actually influence patient outcome. They had a little over 3000 patients and they followed them for 12 months.
Unfortunately, the trial, itself, as far as the primary endpoint, which was change in systolic blood pressure and hemoglobin A1c, they had pretty significant reductions in both arms, about 12 to 13 millimeters, which is amazing from a population health standpoint, in both arms not statistically significant, and in hemoglobin A1c also by 0.5% in both arms.
Just suggesting that having this more frequent interactions with the medical health system, itself, was driving a lot of this benefit. So although the trial, itself, was negative for the primary endpoint, I think it's a huge step forward for the management of chronic disease epidemiology and burden in developing countries.
Dr Gabriel Steg: Neutral.
Dr Carolyn Lam: Ah, true.
Dr Dharam Kumbhani: Fair point.
Dr Carolyn Lam: We've discussed this whole array of seven trials and they are difficult trials. I mean, talk about another difficult type of trial to do, cluster randomized pragmatic trial. It's amazing the breadth of simultaneous publications we've had this year. Thanks again to everyone for introducing this and thank you for joining us today.
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.