HERSHEY, Pa. — Some remain wary of the potential heart health side-effects supposedly linked to COVID-19 vaccines, but new research finds the coronavirus itself is a far greater cardiovascular threat. COVID-19 infection results in a seven times higher risk of myocarditis (inflammation of the heart) in comparison to COVID-19 vaccination, Penn State College of Medicine scientists report.
Common symptoms seen among myocarditis patients include shortness of breath, irregular heartbeat, and chest pain.
“Our findings show that the risk of myocarditis from being infected by COVID-19 is far greater than from getting the vaccine,” says Dr. Navya Voleti, a resident physician in the Department of Medicine at Penn State Health Milton S. Hershey Medical Center, in a university release. “Moving forward, it will be important to monitor the potential long-term effects in those who develop myocarditis.”
Myocarditis is a documented complication resulting from SARS-CoV-2 infections. While COVID-19 vaccines have shown a remarkable capability to reduce COVID symptoms, some patients have reportedly experienced heart complications after vaccination — particularly myocarditis in teenage boys. Up until now, however, scientists have not thoroughly researched the relative risk of myocarditis due to vaccines and infections.
So, the team at Penn State put together the largest study to date on myocarditis risk in connection with either having COVID-19 versus experiencing inflammation following COVID-19 vaccination. They compared patients with COVID, both vaccinated and unvaccinated, to uninfected individuals.
Heart inflammation risk 15 times higher after COVID
That process led to the finding that myocarditis risk was 15 times higher among COVID-19 patients – regardless of vaccination status – in comparison to those who did not contract the coronavirus. Then, the team compared rates of myocarditis separately among those who did and did not receive the COVID vaccine. Researchers note rates of myocarditis among vaccinated individuals were only two-fold higher than among the unvaccinated.
These findings are based on an extensive systematic review and meta-analysis of 22 studies published between December 2019 and May 2022. All of those prior projects encompassed close to 58 million patients who had reported cardiac complications. Additionally, all included patients belonged to one of two groups: the 55.5 million individuals vaccinated against COVID-19 in comparison to those who were not vaccinated (vaccination group), and the 2.5 million people who contracted the coronavirus compared to the uninfected (COVID-19 group).
Within the vaccination group, study authors carefully and separately compared myocarditis risk for numerous COVID-19 vaccines; mRNA (Pfizer, Moderna), Novavax, AstraZeneca, and Johnson & Johnson. The average age of the participants was 49 years-old, 49 percent were men, and the median follow-up time after infection or COVID-19 vaccination was four weeks (28 days).
Men face a higher risk than women
Overall, the majority of patients diagnosed with myocarditis after receiving the vaccine or having COVID-19 were men (61%). Among patients diagnosed with myocarditis across both the vaccination and COVID-19 groups, 1.07 percent were hospitalized, and 0.015 percent passed away.
“COVID-19 infection and the related vaccines both pose a risk for myocarditis. However, the relative risk of heart inflammation induced by COVID-19 infection is substantially greater than the risk posed by the vaccines,” concludes lead study author Dr. Paddy Ssentongo, a resident physician in the Department of Medicine at Penn State Health Milton S. Hershey Medical Center. “We hope our findings will help mitigate vaccine hesitancy and increase vaccine uptake.”
The findings appear in the journal Frontiers in Cardiovascular Medicine.