Abstract
BACKGROUND: Numerous studies have reported myocarditis resulting from messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccination. However, to date, there have been no reports highlighting the safety of mRNA COVID-19 vaccines in children and adults with a prior history of myocarditis, which was the intent of this study. METHODS AND RESULTS: Children and adults cared for at the Cleveland Clinic were identified through the electronic health records, who had a history of myocarditis before the COVID-19 pandemic and had subsequently received at least 2 doses of the mRNA COVID-19 vaccines (n = 34). Only 1 patient in this series had recurrence of myocarditis confirmed by cardiac magnetic resonance imaging after receiving the second dose. He was a White man who had his first episode of myocarditis at age 20 and was 27 years of age at the time of recurrence. He was hospitalized for 2 days with no need for cardiac support or reported arrhythmias and was stable at outpatient follow-up. CONCLUSIONS: In patients with an old history of non-COVID-19 myocarditis, the risk of recurrent myocarditis after receipt of mRNA COVID-19 vaccination is low, and when it occurs it seems to be self-limiting. Our study will be valuable to clinicians while discussing the risk-benefit ratio of vaccinations in patients with a prior history of myocarditis.