Longitudinal Follow-Up of Asymptomatic COVID-19 Myocarditis with Cardiac Magnetic Resonance Imaging

BACKGROUND Varying degrees of cardiovascular involvement have been noted with COVID-19, with myocarditis being one of the feared complications. We present the case of a healthy, young individual with persistent myocardial involvement on cardiac magnetic resonance (CMR) imaging at 10 months' follow-up. CASE REPORT A 23-year-old man with no prior medical conditions presented to our outpatient cardiology clinic with a chief concern of left-sided exertional chest discomfort of 1-week duration, lasting 30-60 min before resolving. The patient was previously active and ran 2 miles per day, 6 days a week without any issues. Three months prior to presentation, the patient had a mild case of COVID-19 managed conservatively on an outpatient basis. On evaluation, the vital signs, physical examination, and laboratory work-up were unremarkable. Electrocardiography (EKG) displayed normal sinus rhythm with incomplete right bundle branch block. Transthoracic echocardiography (TTE) was normal. CMR was performed and indicated myopericarditis in several sub-epicardial and pericardial segments, with a quantitative scar burden of 18.6% on late gadolinium enhancement (LGE) images using the mean+5 SD method. A repeat CMR 7 months later demonstrated persistent sub-epicardial fibrosis with improvement in the LGE burden to 5.1% and resolution of pericarditis. CONCLUSIONS Myopericarditis with persistent myocardial scarring can be detected using CMR in healthy individuals with mild COVID-19 symptoms. The exact prevalence and potential clinical implications of this entity is unclear and warrants further longitudinal research.