No increase in myocarditis and pericarditis after infection among the unvaccinated

In a massive, narrative-breaking study, researchers in Israel found no increase in myocarditis or pericarditis after a positive-PCR test. The study uses data from a health insurance company that included more than 1 million patients. Importantly, the study period was between March 7, 2020 and January 31, 2021 (patients were followed up until February 28, 2021) — thus, the study period should have included the least “mild” variant. You know, the one experts considered so deadly that they valued stamping out western democracy and decimating the world economy over.

In total, 213,624 patients tested posted for COVID and 935,976 tested negative. Interestingly, 16,632 patients were excluded from the COVID cohort for having a vaccination during follow up and only 5 were excluded from the non-COVID, control cohort for vaccination. While this may be due to the fact most cases of COVID occurred in the latter period, and much of the follow up for the controls would have been earlier, the discrepancy between the sizes may add credence to the theory that people who had COVID early on were much more likely to be vaccinated (artificially inflating early vaccine efficacy) as has been observed in U.S. surveys.

In any case, the controls were matched (using age and sex) to the COVID cohort at a 3:1 ratio leaving 196,992 in the COVID cohort matched up against 590,976 controls. The researchers looked at incidence of diagnosis for myocarditis between 10 days and 6 months for each cohort. Some individuals were followed for less than 6 months due to the February 28, 2021 cutoff date.

The researchers then considered two models, a uni-variate model and a multivariate cox regression model that used a variety of factors including: Post-COVID infection, age, sex, BMI, diabetes, hyperlipidemia, obesity, chronic kidney injury, smoking status, peripheral vascular disease, acute coronary syndrome, and essential hypertension.

And the researchers found… no statistical differences in myocarditis or pericarditis between cohorts. Observe graph 1 and 2 below.

Graph 1 blows up the narrative that myocarditis from the virus was ever a reality. In fact, only 36 people (27 in the control cohort and 9 in the COVID cohort… remember the 3:1 ratio) even had myocarditis in a study population of nearly 800,000 followed a long period of time — a disease so rare that almost no one knew its name prior to the vaccination campaign.

Graph 2 is even more interesting. The control cohort actually had a higher, though not statistically significant, incidence of pericarditis. In total, 52 individuals in the control versus only 11 in the COVID cohort got the disease. That is not to say that getting COVID reduces the risk of getting pericarditis (the mechanism for that to be true would be bizarre), but there is certainly no reason to believe it increases the risk in such a large sample size.

The researchers, in the end, found that age and sex were the key contributors to myocarditis, though obesity was borderline significant as well. For pericarditis, sex and peripheral vascular disease were the key contributors.

The study notes it had three key limitations:

First, although the potential number of participants who were considered for inclusion was large, the number of cases of myocarditis and pericarditis was small. This was mainly attributed to the limitation of a relatively short follow-up period due to the initiation of the massive vaccination program. Second, we included only cases of hospitalized myocarditis or pericarditis patients, whereas outpatient medical records were excluded from the study. This could possibly omit a small number of patients with mild disease. Furthermore, we included a diagnosis of myocarditis and pericarditis according to the medical records, without access to patient-based information regarding confirmation of the diagnosis.

I would push back on the first limitation. If there was a significant effect of myocarditis and pericarditis from infection, then the number of cases would not be small in such a large sample size; however, limitations two and three seem reasonable. To play devil’s advocate, I would even add a fourth limitation: some patients who had COVID could be included in the controls — on the flip side, however, patients who had more severe disease (and were at higher risk for myocarditis/pericarditis if the virus causes them) would be more likely to have tested positive. Even further to that point, patients who tested positive would be more likely to have an interaction with the health care system.

This study is compelling, and does a lot to combat the ‘long-COVID’ narrative, despite the authors insistence that it exists. But, ultimately, what I find the most compelling of this study is it shows just how insanely rare myocarditis and pericarditis were prior to the vaccination campaign. Ergo, showing how shortsighted regulators have been worldwide in dismissing concerns from the skeptics because of some imaginary baseline, which appears to have favored the unvaccinated all along.