COVID-19 patients had 15.7 times the risk for myocarditis compared with patients who didn't have COVID-19, with risk varying by sex and age, according to a CDC Morbidity and Mortality Weekly Report published Aug. 31.
CDC researchers examined March 2020 through January 2021 data from Premier Healthcare Database Special COVID-19 Release, a U.S. hospital-based administrative database of healthcare encounters from more than 900 hospitals.
Eight things to know:
1. Myocarditis inpatient encounters were 42.3 percent higher in 2020 (4,560) than in 2019 (3,205).
2. The risk for myocarditis was 0.146 percent among COVID-19 patients and 0.009 percent among patients who were not diagnosed with COVID-19.
3. Overall, myocarditis was uncommon among persons with and without COVID-19; however, COVID-19 was significantly associated with increased risk for myocarditis.
4. Peaks in myocarditis inpatient encounters generally aligned with peaks in COVID-19 inpatient encounters.
5. Among patients with myocarditis, 2,116 (41.7 percent) had a history of COVID-19, with the lowest percentages among persons 16-24 years and the highest among adults 75 and older.
6. Patients with myocarditis were slightly older than patients without myocarditis (54 years versus 50 years) and more commonly male (59.3 percent versus 41.7 percent).
7. Among COVID-19 patients, the risk for myocarditis was higher among males (0.187 percent) than among females (0.109 percent), and was highest among adults 75 years or older (0.238 percent).
8. Since the introduction of COVID-19 vaccines in December, an elevated risk for myocarditis among mRNA vaccine recipients has been observed — particularly among males ages 12-29 — with 39-47 expected cases of myocarditis, pericarditis and myopericarditis per million second mRNA COVID-19 doses administered. Practices concluded that the benefits of COVID-19 vaccination clearly outweighed the risks for myocarditis after vaccination.