Mar 27, 2023
This week, please join author Vincent Aengevaeren and Associate Editor Jarett Berry as they discuss the article "Exercise Volume Versus Intensity and the Progression of Coronary Atherosclerosis in Middle-Aged and Older Athletes: Findings From the MARC-2 Study."
Dr. Gregory Hundley:
Welcome listeners to this March 28th issue, and I am one of your co-hosts, Dr. Gregory Hundley, Associate Editor and Director of the Pauley Heart Center at VCU Health in Richmond, Virginia.
Dr. Peder Myhre:
And I'm Dr. Peder Myhre, Social Media Editor from Akershus University Hospital and University of Oslo in Norway. And today, Greg, we have such an interesting feature paper. It comes to us from Professor Aengevaeren and it discusses the progression of coronary atherosclerosis in middle-aged and older athletes. They're looking at exercise volume versus intensity in the MARC-2 study. So Greg, this is really something us master athletes are interested in, and I'm really excited to hear this discussion.
Dr. Gregory Hundley:
Very nice. Well, how about we jump into some of the other articles first, Peder? And I could go first. So Peder, my first article involves pregnancy related complications. And as you know, these pregnancy complications are associated with increased risk of developing cardiometabolic diseases and an earlier mortality. However, much of the prior research has been limited to individuals of White race. So these investigators led by Professor Cuilin Zhang from the National Institutes of Health aimed to investigate pregnancy complications in association with total and cause specific mortality in a racially diverse cohort, and then evaluate whether associations differ between Black and White individuals. And they performed their work using the Collaborative Perinatal Project, which was a prospective cohort study of 48,197 pregnant women across 12 US clinical centers from the period of time of 1959 through 1966.
Dr. Peder Myhre:
Oh wow, Greg. Almost 50,000 pregnant women. Very huge initiative. So what did they find?
Dr. Gregory Hundley:
Right, Peder. So overall, 15% of participants had preterm delivery, 5% had hypertensive disorders of pregnancy, and 1% had gestational diabetes or impaired fasting glucose. Now, the preterm delivery was higher in individuals of Black race at 20% relative to those of White race, which were 10%. Now, in relation to all-cause mortality, the following were associated with increase adjusted hazard ratios. One, spontaneous labor; two, induced labor; three, pre-labor cesarean delivery. And all of those, those adjusted hazard ratios in comparison with a full term delivery.
Next, in the world of blood pressure, preeclampsia and eclampsia as well as superimposed preeclampsia and eclampsia were all associated with adjusted hazard ratios that were elevated compared to individuals with normal blood pressure. And then finally, in those individuals with gestational diabetes or impaired fasting glucose, their adjusted hazard ratio, again for all-cause mortality, was elevated relative to those with normal glycemia. Now interestingly, in comparing the two racial groups, preterm induced labor was associated with greater mortality risk among those of Black race relative to those of White race. However, or while, preterm pre-labor cesarean delivery interestingly and conversely was associated with a higher adjusted hazard ratio for those of White race as compared to individuals of Black race.
So Peder, in summary, within this large diverse US cohort, pregnancy complications were associated with higher mortality almost 50 years later. And the higher incidents of some complications occurred in individuals of Black race. And differential associations with mortality risk indicate that because of these racial differences, there could really be disparities in pregnancy related health. And finally, that these disparities and their relationship with overall health really could have long life implications for earlier mortality in these patients.
Dr. Peder Myhre:
Well, that is really interesting, Greg. Are you ready for the next paper?
Dr. Gregory Hundley:
Absolutely.
Dr. Peder Myhre:
So this paper is about the glucagon-like peptide-1 receptor agonist and large CV outcome trials clearly show that several GLP-1 agonists reduce CV outcomes in patients with Type 2 diabetes. Whether their cardioprotective effects are related to drug dose or potency remains uncertain however, but important due to recent introduction of high dose and high potency agents for diabetes and for weight loss indications. And therefore, Greg, in this paper, the investigators from the AMPLITUDE-O trial led by corresponding author Hertzel Gerstein from McMaster University Hamilton Health Sciences analyzed the effect of the different doses of the GLP-1 agonist efpeglenatide that is four milligram, six milligram compared to placebo. And the effect was assessed on major adverse cardiovascular events.
Dr. Gregory Hundley:
Interesting, Peder. So what did they find?
Dr. Peder Myhre:
So Greg, during a median follow-up of 1.8 years, MACE occurred in 9.2 participants assigned to placebo, 7.7 in participants assigned to efpeglenatide four milligrams, and 6.2% in participants assigned to efpeglenatide six milligrams. And participants receiving high dose of this GLP-1 agonist also experienced fewer secondary outcomes, including the composite of MACE coronary revascularizations or hospitalizations for unstable angina, a kidney composite outcome comprising sustained new microalbuminuria, decline in eGFR more than 40%, or renal failure. And there was also a clear dose response relationship noted for all primary and secondary outcomes with a P4 trend that was significant. So Greg, the authors conclude that the graded relationship between efpeglenatide dose and CV outcomes suggests that titrating this drug and potentially other GLP-1 agonists to high doses may maximize their cardiovascular and kidney benefits.
Dr. Gregory Hundley:
Very nice, Peder. Well, my next paper comes to us and involves the world of bleeding associated with Factor Xa inhibitors. So Peder, andexanet alfa is a modified recombinant inactive Factor Xa designed to reverse Factor Xa inhibitors. ANNEXA-4 is a multicenter prospective phase 3B single group cohort study that evaluated andexanet alfa in patients with acute major bleeding. And the study is led by Dr. Truman Milling of Seton Dell Medical School Stroke Institute and colleagues, and they present the results of their final analyses.
Dr. Peder Myhre:
Oh, this is really interesting, Greg. So what did they find?
Dr. Gregory Hundley:
Right, Peder. So first, 479 patients were enrolled. And their average age was 78 years. 54% were men, 86% were White. 81% of the individuals enrolled were anticoagulated for atrial fibrillation. And they had received this drug 11 hours median time since the last dose. 51% of the individuals were on a apixaban, 37% were on rivaroxaban, and 8% were on edoxaban, and then finally 5% were on enoxaparin. Now bleeding, Peder, was predominantly intracranial in 69%, it was GI in 23%. In evaluable apixaban patients, median anti Factor Xa activity decreased from 146.9 to 10 nanograms per milliliter. That's a 93% reduction. In rivaroxaban patients, it decreased from 214 to 10.8 nanograms per milliliter. That's a 94% reduction. In edoxaban patients, it decreased from 121 to 24 nanograms per milliliter; a 71% reduction. And in enoxaparin, it decreased from 0.48 to 0.11 international units per milliliter or a 75% reduction.
So Peder, excellent or good hemostasis occurred in 274 of the 342 evaluable patients. So in 80%. In the safety population, thrombotic events occurred in about 10% of patients. And in 16 patients, this occurred during treatment with prophylactic anticoagulation that began after the bleeding event. So no thrombotic episodes occurred after oral anticoagulation restart. So Peder, in conclusion, in patients with major bleeding associated with the use of Factor Xa inhibitors, treatment with enoxaparin and andexanet alfa reduced anti Factor Xa activity and was associated with good or excellent hemostatic efficacy in 80% of patients.
Dr. Peder Myhre:
Oh wow. That was really impressive.
Dr. Gregory Hundley:
Yeah, what a very practical study. Well, Peder, we have some other articles in the issue. How about I go first? So first, there's a Research Letter from Professor Eleanor entitled “A Mouse Model of Atrial Fibrillation in Sepsis.” And then from Tracy Hampton we have some Cardiology News. First from Professor Shane et al, a paper on the impact of coffee subtypes on incident cardiovascular disease, arrhythmias, and mortality, long-term outcomes from the UK Biobank study, which is published in the European Journal of Preventive Cardiology. Next from Professor Morashige, there is a paper entitled “Extra Cardiac BCAA Metabolism Lowers Blood Pressure and Protects From Heart Failure.” And that's published in Cell Metabolism. And then finally from Professor Kessler and associates, the paper is entitled “Common and Rare Variant Associations with Colonial Haematopoiesis Phenotypes.” And that particular paper is published in Nature.
Dr. Peder Myhre:
That's great, Greg. And we also have an exchange of letters by Dr. Ding and Dr. Kirshenbaum regarding the article “Proteasomal Degradation of TRAF2 Mediates Mitochondrial Dysfunction in Doxorubicin-Cardiomyopathy.” And finally we have On My Mind by Bertram Pitt entitled “Early Implementation of aldosterone Targeted Therapy in Patients with Hypertension.” Now Greg, let's go to the feature paper to discuss the progression of coronary atherosclerosis in middle-aged and older athletes.
Dr. Gregory Hundley:
Very good. Let's go.
Welcome listeners to this feature discussion on March 28th. And we have with us today Dr. Vincent Aengevaeren from Radboud University Medical Center in Nijmegen in the Netherlands. And also with us one of our associated editors, Dr. Jarett Berry from University of Texas Southwestern Medical Center in Dallas, Texas. Welcome gentlemen. Well, Vince, we'll start with you. Can you describe for us some of the background information that went into the preparation of your study and what was the hypothesis that you wanted to address?
Dr. Vincent Aengevaeren:
So this specific study is actually a follow-up study of a previous study that we did on the relationship between exercise and coronary atherosclerosis. The original study was published also in circulation in 2017 and it really looked at the association of relationship between exercise volume, lifelong exercise volume and coronary atherosclerosis. And at that time we found that there was actually a sort of paradoxical association between lifelong exercise volume and coronary atherosclerosis that with higher lifelong exercise volumes, there was a dose upon dependent association with the prevalence of coronary atherosclerosis.
And there was actually in the same issue, there was another paper in 2017 from a London group shown similar findings. And actually, yesterday on the ACC, there was another paper also showing increased coronary atherosclerosis in athletes. And this study of course there was also some critic like is this caused by confounding, these were observational perceptional studies, could there be other factors playing, but also none of the studies looked at the differentiation between exercise volume and exercise intensity. So the composition of the exercise. So that was the main question actually for this study. We want to do a follow-up study after at least five years do another CT scan, again, get everyone back the questionnaire, exercise habits, and then also specifically look at exercise volume versus exercise and density.
Dr. Gregory Hundley:
Very nice. So it sounds like in this study you have a cohort that you're following over time. So maybe describe for us a little bit more the specific study design and who is included. Who is your study population here?
Dr. Vincent Aengevaeren:
The study population is called the MARC study, Measuring Athletes Risk of Cardiac events. And the study was originally designed mainly based on the fact that healthy athletes, mainly male athletes, sometimes suddenly die of coronary atherosclerosis, which is not really recognized beforehand. So the main study idea was to look at healthy male athletes who didn't experience any symptoms and who underwent the screening, including an exercise test with EKG with normal findings and who then subsequently underwent a coronary CT scan. So blank CT scan for corona calcification score, but also contrast enhanced CT scan to look at the degree of coronary atherosclerosis to those of [inaudible 00:15:18] characteristics.
So that's how the original study was designed and it included 318 male individuals over the age of 45 with a very heterogeneous exercise exposure. So they all had to do some type of sports, but there was no minimal dose. So it really depended. So we have some very high level athletes, but also some more of the regular people who exercise a lot less. So very heterogeneous exposure. And for this study, so in the follow-up study, we actually included 291 of those 318 individuals after six years, which I was pretty happy with. And for this specific analysis we excluded two individuals due to their PCI in between. So that's pretty much the cohort that we're looking at. And during this follow-up period of six years, they did the equivalent of about 40 MET hours per week, which equates to about five hours of the exercise.
Dr. Gregory Hundley:
Very nice. And Vince, you said you had a very diverse group. I mean, a lot of times I'll think about the extremes here. Folks that do a lot of aerobic exercise, those that I think about the power weightlifter. What kind of distribution of athlete, maybe just some practical identifiers for our listeners here.
Dr. Vincent Aengevaeren:
So it's a very important point. So the main type of athletes in this group who are endurance athletes, so mainly runners and cyclists. Of course also some other type athletes and some athletes do multiple type of sports, but mainly runners and cyclists and definitely large proportion of [inaudible 00:16:53] athletes.
Dr. Gregory Hundley:
Very nice. So Vince, describe for us your study results.
Dr. Vincent Aengevaeren:
During this follow-up period, and it's important to state that for this follow-up study we used the exercise characteristics during the follow-up period, we found that exercise volume during follow-up was not associated with progression of coronary atherosclerosis, but exercise intensity was. So we defined exercise intensity based on the MET score, the metabolic equipment of task score, which is derived from previous studies. And there's a compendium explaining MET scores for all the different sports and we used that to categorize the different sports. And we've found that vigorous intensity exercise, for example cycling, was associated with less progression of coronary calcification, but very vigorous intensity exercise, for example running was associated with more progression or coronary calcification. And if you then also look at plaque types, we also saw that those who did the most very vigorous exercise also had a bit more calcified plaque progression. So that was the main findings.
Dr. Gregory Hundley:
And Vince, describe for our listeners, many whom are cardiologists or others fellows, et cetera. Can you give me a specific example of vigorous exercise versus very vigorous exercise? Like, if I'm doing something during the week, describe for me those two categories, examples.
Dr. Vincent Aengevaeren:
So typically, and of course this is a very typical vigorous exercise was cycling and very vigorous exercise was running. But of course as you do cycling at a higher intensity, for example spinning on a spinning bike, it's traditionally at a higher exercise intensity. So that was counted as a very vigorous intensity exercise. And I have to say this was based on questionnaire data, so I did not have six-year or lifelong heart rate data. So it is based on questionnaire data, the categorization of exercise intensity. That's a good example. Other things of [inaudible 00:19:03] intensives, for example, soccer, hockey, I don't know how popular those sports are in America, but those are pretty popular in Netherlands as well.
Dr. Gregory Hundley:
When you mean very vigorous for some of our runners out there, I mean for the casual runner that might run two or three miles a day, is that very vigorous or are you talking about someone that's training periodically for marathons and running three or four marathons a year?
Dr. Vincent Aengevaeren:
That is really more, I guess, about volume. So if people do a lot of marathons, that can actually be at a lower intensity. Like, with intensity, we really, really mean the heart rate intensity and not the intensity of the volume. So I have to specify that. It's really exercise intensity such as for oxygen consumption or heart rate and not the volume in the hours per week. So typically the runners that we had were mostly very vigorous runners. So couple hours per week traditionally they did like trainings of one and a half hour, which is usually at a higher intensity.
Dr. Gregory Hundley:
Very nice. Well listeners, now we're going to turn to one of our associate editors, Dr. Jarett Berry, who really has some expertise in this area. And Jarett, you see many papers in circulation. What do you find is unique about this particular study and then how do you put its results really in the context of other studies that have focused on exercise both in duration as well as intensity?
Dr. Jarett Berry:
Yeah, thanks Greg. And Vince, a fantastic paper, such a privilege to be able to visit with both of you today about this important paper. I think if you take a step back here, challenges I think we all have as physicians is dealing with these uncertain questions that arise clinically where you encounter patients who are exercising at these extreme levels. And although it's not super common, we do encounter these scenarios clinically. And what we need in context like this is we need some data and understanding of what's happening clinically to be able to provide guidance. And so we're really in a context like this in a scenario where we have the common clinical problem of incomplete information. And I think it's studies like this that really help us move the needle to help us understand how to think about those patients of ours that exercise at very high levels.
I do think it's important to put it into context, about 10% of the participants in this study exercised below 1,000 minutes per week. And so for those of you taking notes at home, that's the guidelines in 500 and 1,000 minutes per week would be, I mean you'd be hitting the guidelines. And two-thirds of these individuals were exercising at 2,000 minutes per week. So I think it's important to put it into context when we think about applying and understanding the question about toxicity of exercise, putting that into context that most of the patients that we encounter are not exercising at these high levels. However, as I mentioned, we do encounter this and we have to know what to do with it.
The key here I think is... The other context is with a point that's been raised already in some of the questions and discussion is the heterogeneity that we see in individuals who exercise at these high levels. When you're trying to think about dose of exercise, we have to think about not just intensity but volume. And I think what the study's done here has done a really nice job of trying to parse that out because we can achieve the dose of exercise that's recommended or the dose of exercise that we want to achieve for personal reasons, but we can get there through different ways. We can get there through more hours or we can get there through a higher intensity. And then of course, obviously combinations of the two.
And I think this study here does two things for us. Number one, it gives us a delta question. We've seen this before with just looking cross-sectionally and we have all the challenges that come with that with regard to recall of exercise. Here we have a prospective cohort that we're following or that events followed. And secondly, the ability to parse out both volume and intensity over time. And I think that for me, the finding that really sticks out is that in addition to all the complexities that are right here, we see that the story with regard the components of the dose may not be uniform. That intensity or exercising at very high intensity may be a different part of the equation beyond just volume.
And I think that as we think about counseling our patients as they are engaging in this type of high level of exercise, I think it's one additional component of our way of interpreting this and providing counsel to these patients about how to think about volume and intensity. And maybe these data suggests the hypothesis that the volume part of the dose equation may be safer or maybe something that's more palatable for the heart perhaps over time than the intensity. I think the big elephant in the room, of course, is the fundamental question is that we're dealing with an intermediate phenotype and we know lots of observational data showing that more atheros bad. We all recognize that, but you can get to athero through different mechanisms here.
And I think that these data and others suggest that exercise is one mechanism perhaps that though you can get athero, the question is what is the true clinical significance from a [inaudible 00:24:32] standpoint down the road as we try to extrapolate the intermediate phenotype into the future. And I think there's controversy, I think agreement about what the intermediate phenotype means in these high volume exercisers. And I think that question remains unknown, I think.
But in the interim, as I said in the beginning, that as we think about putting all this into context, we don't have perfect information and we do have to take the information that we do have to provide the counsel that we need to provide if these patients. And I think I take away from this that when providing counsel, maybe I lean more towards volume and less towards this really high volume, sorry, this really high intensity for those individuals whose coronary calcium or their athero burden is particularly high. But a fantastic study. Another step in the road and it's really trying to understand an incredibly complex story and one that will continue to unfold.
Dr. Gregory Hundley:
Very nice, Jarett. And listeners, we're going to turn back to both Vince and Jarett here each in 30 seconds. Vince, what do you see as the next study that your group or others might want to be considering in this sphere of research?
Dr. Vincent Aengevaeren:
For me personally, the next big thing that we should do is really cardiovascular risk. So what's the clinical relevance of this finding? So coronary calcification is strongly associated with cardiovascular risk, but how that is in these athletes in which we see increased coronary calcification, that's still pretty much the question. I mean, any plaque is worse than no plaque, but how is this for the very vigorous exercisers who may show some more calcification and whether that risk is different. I mean, that's the question that all the athletes that email me after this type of publication have the question. And also the mechanisms. Like, what are the underlying mechanisms? That's also a next lead study for me.
Dr. Gregory Hundley:
Very nice. And Jarett?
Dr. Jarett Berry:
Yeah, I think the ultimate question is, I completely agree, is what is the clinical significance. I think that's going to be... That's a challenging question to answer just because of the on average these individuals are more rare. And so following these individuals over time to really tease out the clinical significance of this type of athero in these athletes, I think, is a challenge. I think for me the next step would be more studies like this where we can get more granular with regard to measured exercise intensity. I think wearable devices, things that Vince alluded to with regard to heart rate, really trying to get more quantitative to try to parse out the contribution of more objectively measured exercise intensities, I think would probably, for me, represents kind of probably the next step, is digging a little deeper into the phenotype and being a little bit more precise perhaps with studies like this to help us begin to understand the significance of these findings.
Dr. Gregory Hundley:
Very nice. Well, listeners, we want to thank Dr. Vincent Aengevaeren from Radboud University Medical Center in Nijmegen in the Netherlands, and our own associated editor, Dr. Jarett Berry from University of Texas Southwestern Medical Center in Dallas, Texas for bringing us this study highlighting that exercise intensity but not volume was associated with progression of coronary atherosclerosis during a six-year follow-up of this cohort of really trained athletes and intriguingly the very vigorous. So we want to distinguish that. The very vigorous intensity exercise was associated with greater coronary artery calcium calcified plaque progression, whereas simply just vigorous intensity exercise, casual riding of the bike, casual running, et cetera, was associated with less coronary artery calcium progression.
Well, on behalf of Peder and Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. This program is copyright of the American Heart Association 2023. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit ahajournals.org.