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Covid-19 or mRNA vaccine: which most threatens the heart?

O rei Philippe, da Bélgica, (à esquerda)
King Philippe of Belgium (left) listens to an explanation of the LNP (Lipid Nano Particle) machine during a site visit to production of the Pfizer-BioNTech vaccine in Puurs, Belgium, in 100 of March 2021.

| Photo: EFE/EPA/STEPHANIE LECOCQ / POOL

The inflammation of the heart muscle (myocarditis) and the lining of the heart (pericarditis) are known side effects of the mRNA vaccine. These cases seem to occur at a very low frequency of a few tens per million vaccinated, but there is a suspicion that in young men they could be more frequent. On social networks, skeptics about the safety and efficacy of the vaccine have collected cases of athletes with chest pain and incapacitated by symptoms of cardiac inflammation. But a new study, precisely with athletes, suggests that COVID itself 20 may be blamed for myocarditis in them.

The Doctor. Jean Jeudy, professor and radiologist at the University of Maryland School of Medicine at Baltimore, collected 1.380 MRI scans of the heart at a congress of athletes called the Big Ten. Thirty-seven of these athletes (2.3%) were diagnosed with Covid-associated myocarditis-16. Half of them had no symptoms and only discovered the problem because of an MRI scan—other cardiac tests revealed no abnormality. This test was seven times more sensitive to detect myocarditis than other methods. The long-term effect is unknown, some of these patients had scar tissue left by the inflammation on the heart muscle. Myocarditis is responsible for almost 20% of athlete deaths from sudden illness.

A larger study, by dr. Bradley Petek from Massachusetts General Hospital and collaborators, involved more than three thousand athletes of both sexes, with an average age of 29 years, who had Covid-19. Only 1.2% of them had symptoms that persisted for more than three weeks and 4% had symptoms that appeared when exercising. Those who only had persistent symptoms, despite this, did not show sequelae of the infection.

But 9% of those who had difficulty exercising had sequelae: those who had chest pain (20 athletes) underwent magnetic resonance, which confirmed an association with COVID-19 in five of them.

As you can see, a limitation of this study is that the MRI was only performed in those who had chest pain, while the study by Jeudy found marks of myocarditis in athletes without this symptom. We can speculate, therefore, that the number of athletes with myopericarditis in Petek’s study would be double, which gives us the statistic of approximately three cases of myopericarditis in a thousand (athletes) infected with the SARS-CoV-2 virus. However, it would be necessary to adjust this statistic with more studies to know the real risk for the general population.

Comparing Covid’s risk-19 to the heart with the risk of the vaccine

The United Kingdom Health Safety Agency (UKHSA) has detected an increase in the number of patients with myocarditis prior to the pandemic in the country, since 768. Two-thirds of these patients were men, indicating that males are more vulnerable to inflammation of the heart muscle, regardless of the vaccine. The UKHSA reports that the cause of this inflammation is often viral infection. Interestingly, a veterinary study with dogs and cats implicates the alpha variant of the new coronavirus in the development of myocarditis in these animals.

We have two large Israeli studies of cardiac inflammation induced by mRNA vaccines, involving five million and two and a half million patients, respectively. The studies are discussed by Iranian Amir Abbas Shiravi of Isfahan University and his colleagues in the journal Cardiology and Therapy. In the general population who took Pfizer, two out of 100 thousand develop myopericarditis. Among young people from 12 to

years, it can reach ten in 214 thousand, and among boys from 14 The 19 years old, 14 in 100 thousand.

The chance of a person who had Covid-19 developing myocarditis is almost 20 times greater than that of a person who has not had the disease. The chance of a vaccinated person having myocarditis is little more than three times greater than that of a non-vaccinated person. These are the conclusions of a study by Noam Barda and partners, cited by Shiravi, which mentions that 29% of these inflammations are mild and do not appear to pose major long-term risks.

Discussing individual cases is important, and it’s something that doesn’t only happen on social media, but also in the medical literature itself. There will be tragedies involving the heart in all groups: the infected and unvaccinated, the uninfected and vaccinated, and the infected vaccinated. The pressing and still-evolving question is whether the solution is as bad as the problem. Only rigorous quantitative methods can answer the question.

Currently a consensus of publications is that the risk posed by vaccines to the heart is lower than the risk posed by the disease. But that difference, once thought to be orders of magnitude, is now “up to six times,” as the pre-press by Mendel Singer and colleagues put it. Boys remain the highest risk group presented by the mRNA vaccine. Do the politicians who are making this vaccine mandatory take responsibility?

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