Myocarditis was a well-known reported side effect of COVID-19 vaccines, but heart issues were also a reported symptom of COVID-19 infection. The CDC published a Morbidity and Mortality Weekly Report comparing the risk of cardiac complications after SARS-CoV-2 infection with mRNA COVID-19 vaccination.
Based on data from 40 health care systems’ electronic records (EHR), the cardiac complications were found to be significantly higher after infection than after vaccination. This was the case for both genders and in all age groups.
Researchers looked at the incidence rates of myocarditis, pericarditis, and multisystem inflammatory syndrome (MIS). Affecting both children and adults, MIS is a rare response of a person’s immune system to COVID-19 that can damage the heart, lungs, kidneys, brain, skin, eyes, and GI organs. Symptoms of MIS can appear days to weeks after initial infection. Eighty percent of MIS cases are said to involve the heart.
Looking at younger male populations, a group at highest risk for myocarditis from vaccinations, the CDC reports teenage males aged 12 to17 years old had the highest incidence of cardiac complications after vaccination, particularly after the second dose. But after infection, incidence rates of cardiac problems in this same group were 1.8 to 5.6 times higher.
Young adult males aged 18 to 29 years old had a 7 to 9 times greater risk of cardiac complications from infection versus 2 doses of vaccine. Females aged 12 years or older had a 6 to 63 times higher risk after infection compared to vaccination.
The CDC states that overall, based on this EHR data, the incidences of cardiac complications after infection or vaccination are low. Studies in Israel and the UK have reportedly also found higher incidence rates of myocarditis from infection versus vaccination.
Sources: JAMA Network, CDC, New England Journal of Medicine