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No, mRNA vaccines for COVID-19 do not dramatically increase the risk for heart attacks

For my very first contribution, I will write about a study that is currently circulating in the anti-vaccine scene, and is partly seen as evidence that mRNA vaccines from Pfizer or Moderna will cause serious side effects in the heart. I became aware of this through a message from someone I know. Here are a few examples of how this study is presented on Twitter.

Whether mRNA vaccines cause massive side effects in the heart is a very interesting and of course also very important question, especially since it it is known that mRNA vaccines do in some cases cause inflammation of the heart muscle.

It would indeed be devastating if the study's conclusions were correct. So I looked into it more closely. Does the data really show what the anti-vaxxers make of it? Are the author's conclusions justified at all? Does the data even show what the author claims it does?

Since I'm not a cardiology expert, I did need to do some research first. When I started researching this a few days ago, I didn't find any secondary reports from news articles that have more than the abstract. I also found no criticism from other experts so all of the comments here are 100% my own thoughts.

First of all, I would like to note that this is just a poster, not a complete article. This means that the peer review, i.e. appraisal of the work by other experts in the field, has so far only been done on the basis of the summary (in other words, not really at all). The organizers of the meeting by the American Heart Association where this was presented decided to select the poster based on the abstract only. Despite the fact that if the author's conclusions were correct, that would have dramatic consequences for the entire field of cardiology, the organizers selected this study only for a poster, not an oral presentation. You can already guess how much confidence they must have had in the study. w Since I don't have access to the full poster, I can only look at what is in the abstract. Let's see if that's enough to decide what was actually done, whether it was properly analyzed and evaluated and to decide whether the conclusion is justified.

What was actually done and what exactly does the study say? It looks like blood samples from 566 patients who are regularly seen after in the author's practice were analyzed from 2 to 10 weeks after a COVID-19 vaccination with an mRNA vaccine. A supposedly clinically validated test called PULS Cardiac Test was used (though I found no evidence that it is widely used in the USA). According to the manufacturer it can predict how high the risk (probability) is of having a heart attack within the next few years. The test looks at 9 different bio-markers, which, according to the manufacturer are combined into a single score, that can say something about how damaged the blood vessels are and therefore also how high the probability of getting a heart attack is. According to the author, 3 of the 9 values are significantly increased​​in subjects who were vaccinated in the previous 2-10 weeks, and that even over the entire period of up to 10 weeks.

"Baseline IL-16 increased from 35=/-20 above the norm to 82 =/- 75 above the norm post-vac; sFas increased from 22+/- 15 above the norm to 46=/-24 above the norm post-vac; HGF increased from 42+/-12 above the norm to 86+/-31 above the norm post-vac"

Three markers are increased (but no p-value is given) and there is also no explanation as to whether statistical significance was checked for at all (if you test 9 different markers, you would also have to correct for multiple testing which we are also told nothing about). The patients are compared with their own most recent value that was taken before the vaccination. The increase in the measurement for the biomarkers compared to the normal limits ​​is compared between before and after. The standard deviations (I assume the numbers with =/- or + - are standard deviations, it is not explicitly stated) are quite wide and partially overlap. Without proper statistical analysis, the whole thing is really difficult to interpret. An analysis of how strongly the observed effect is driven by early measurements (closer to 2 weeks), and how strong the effect should still be in later measurements (closer to 10 weeks) is not shown here. There is a vague statement, but we do not get the details. However, this is quite important for justifying the conclusion. Data for a control group with unvaccinated or recovered from COVID-19 are also not shown, but would be very helpful for interpretation.

But what do these markers actually mean? Two of the elevated markers are primarily markers for the immune system (Fas and IL-16) and only secondarily associated with heart or atherosclerosis. It has long been known that certain immune markers can be elevated in the days and weeks after a vaccination and this does not necessarily have anything to do with the heart or the blood vessels. It is therefore important to know exactly when samples were taken during the period of 2-10 weeks. There are various statistical tests and graphical representations that could help understand this. Unfortunately none of this is described in the abstract. The third elevated marker is HGF. You can already see from the name, hepatocyte growth factor, that this is not a classic marker for cardiac health either. HGF, Fas and IL-16 have many effects in the body, including the immune system. Even if these markers were elevated in the patient's blood even weeks after the vaccination, that does not mean that this has anything to do with the blood vessels.

Are there other diagnostic tests that would have better indicated heart muscle inflammation? I find it particularly strange that classic markers for cardiac health such as LDH, CK-MM or troponin I or other inflammation markers such as CRP are not even mentioned in this abstract. Any cardiologist would ask about them right away, as these are very sensitive markers to tell if a patient's heart muscle has been damaged. Unfortunately, these tests are not part of the panel that was tested here. A statistical increase in even a fraction of the patients would be quite worrisome, if the study was showing it. But it isn't. An analysis of EKGs would also have been interesting, if any were done.

The study claims that these patients have a dramatically increased risk of acute coronary syndrome (ACS). Were more such events observed in these 566 patients? If the vaccines really increased the risk for ACS etc. by as much as is claimed in the study, the corresponding events (unstable angina and myocardial infarction) should very soon occur more frequently in the vaccinated cohort than in an unvaccinated control cohort. Other cardiologists would then have to have observed a massive increase and be able to publish it. An effect so large would have been actually been visible in the large Phase 3 trials used to get approval for the vaccines. Even in the much smaller cohort of this study it would almost be possible to detect a difference. As a rule, it is always better to first quantify a phenomenon before looking for supposed mechanisms. Maybe it's not enough for a statistical test, but this study would be much more convincing if there was at least a trend worth mentioning. Perhaps the duration of the follow-up is not long enough. The number of events would be small and would need a comparable control group. The study could have used the same patients 10 weeks before the second vaccination vs. 10 weeks after. An actual increase of 11% to 25% in the 5-year ACS risk should have caused about 3 additional events in 588 patients in 10 weeks of follow-up, about 2 to 5. Perhaps the data is in the poster, but as it is not in the abstract, it is not convincing at all.

Is the conclusion justified?

"We conclude that the mRNA vacs dramatically increase inflammation on the endothelium and T cell infiltration of cardiac muscle and may account for the observations of increased thrombosis, cardiomyopathy, and other vascular events following vaccination."

The author concludes from this that not only are the blood vessels at risk, but that immune cells invade the heart muscle, thereby increasing the risk of heart disease. (That the PULS test can do this is not even claimed by the manufacturer of the test). The markers that were measured that are involved in many different biological processes. Just because these markers also correlate with heart health when they are chronically elevated, presumably because of a general link with atherosclerosis and vascular inflammation, this does not mean that this causality must also be present in these test subjects. There are many other possible hypotheses as to why immune markers are elevated after vaccination. Inflammation of the heart muscle or blood vessels is just one of them. Here the author probably has a fundamental problem with understanding what the markers mean and how / why the PULS score works. The most obvious alternative hypothesis is that it was the vaccination directly, without the heart or blood vessels having anything to do with it. Without seeing the data that these markers actually remain as elevated as claimed for a long period, and that this is statistically significant, this study is not even succeeding in showing a mechanism, definitley not in showing an effect.

How much confidence does this study inspire? Here are a few observations that have nothing to do with science, but which in my opinion strongly influence the credibility of the author and the study. First to the author. The author is a single 71 year old retired cardiac surgeon who apparently did all of the work without a any help, as there is no co-author. That’s astonishing. His institution (The International Heart and Lung Institute, Palm Springs, CA) sounds like it is part of a university or research facility. In fact, it is a private company. It is also interesting that he had not published anything since 2004 before this study. And even then, none of his previous scientific work has anything to do with the research done in this study. What is wrong with all the retired old men who dare to go beyond their expertise and make fools of themselves in the process? He is not the only example. On top of that, he writes books on questionable diets and sells them on his own website. The guy has even written articles for Gwyneth Paltrow's Goop. He even has his own online grocery store. That doesn't inspire a lot of confidence in me. I would also like to mention the sloppy text editing and proofreading. The first sentence has PLUS instead of PULS and in the abstract there he uses several times =/- instead of +/-. The use of the colloquial and not very scientific “percentage chance” indicates that the author probably has little experience with statistics. But these superficial points do not by themselves mean that science is bad. That's why this comes at the end and is not the basis of my overall assessment.

Conclusion I would not advise anyone against the mRNA vaccinations because of this study. This study provides absolutely no evidence that these vaccines increase the risk of heart disease in high numbers of vaccinated persons.

Why did the anti-vaxxers even bother to promote it? The fact that the anti-vaxxers present this study as proof of how harmful mRNA vaccines are supposed to be shows in my opinion that

  • no better data is available and

  • they do not understand the science in the abstract.

Otherwise the study would not have been presented and shared in the way it was. Should I ever get access to the poster, or if a scientific article is published in full, I'll be happy to look at it again.

But the mRNA vaccines do cause myocarditis. Why are people still being vaccinated with them at all? What people should consider is that there is long-known association between viral infections (e.g. influenza) and EKG changes as well as heart muscle inflammation (also known as myocarditis). This has been known for decades and is also the case in young people. This effect has now also been observed for Covid-19. There are good reasons why doctors advise against exercise (especially high impact exercise at the limit) during an acute cold. One reason for that is that it increases the risk of myocarditis. All side effects caused by the vaccines (nobody denies that they exist) must therefore also be considered in relation to the risks of an infection (even the rare risks) and the severity / frequency must be compared for each age/risk group separately. There are now good publications on myocarditis based on large data sets, both for vaccinations as well as for the disease. All rigorous, systematic and scientific evaluations indicate that the ratio of benefit to risk favors the vaccines, even in younger patients.

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