CMR Imaging 6 Months After Myocarditis Associated with the BNT162b2 mRNA COVID-19 Vaccine

Abstract

Temporal association between BNT162b2 mRNA COVID-19 vaccine and myocarditis (PCVM) has been reported. We herein present early and 6-month clinical follow-up and cardiac magnetic resonance imaging (CMR) of patients with PVCM. A retrospective collection of data from 15 patients with PCVM and abnormal CMR was performed. Clinical manifestation, laboratory data, hospitalizations, treatment protocols, and imaging studies were collected early (up to 2 months) and later. In nine patients, an additional CMR evaluation was performed 6 months after diagnosis. PCVM was diagnosed in 15 patients, mean age 17 ± 1 (median 17.2, range 14.9-19 years) years, predominantly in males. Mean time from vaccination to onset of symptoms was 4.4 ± 6.7 (median 3, range 0-28) days. All patients had CMR post diagnosis at 4 ± 3 (median 3, range 1-9) weeks, 4/5 patients had hyper enhancement on the T2 sequences representing edemaQuery, and 12 pathological Late glandolinium enhancement. A repeat scan performed after 5-6 months was positive for scar formation in 7/9 patients. PCVM is a rare complication, affecting predominantly males and appearing usually within the first week after administration of the second dose of the vaccine. It usually is a mild disease, with clinical resolution with anti-inflammatory treatment. Late CMR follow up demonstrated resolution of the edema in all patients, while some had evidence of residual myocardial scarring.

Keywords: COVID-19; Cardiac magnetic resonance imaging (CMR); Follow-up; Myocarditis; Vaccine.