Imaging of Myocarditis Following mRNA COVID-19 Booster Vaccination

Abstract

A late adolescent male patient presented with chest pain and palpitations starting 3 days after administration of the third dose of BNT162b2 mRNA COVID-19 vaccine. First and second doses of BNT162b2 mRNA had been administered 4 and 5 months prior (homologous vaccine schedule). Troponin T level was 337 ng/L at presentation and peaked at 1610 ng/L. Basal short-axis 1.5-T cardiac MR images demonstrate subepicardial late gadolinium enhancement at the basal inferior and inferior lateral wall (Fig A, red arrows), with corresponding hyperintensity on T2-weighted image (Fig B, orange arrows), abnormal high regional native T1 (Fig C; 1123 msec, blue arrows [upper reference range, 960 msec]), and abnormal high regional T2 (Fig D; 58 msec, green arrows [upper reference range, 51 msec]). These findings are in keeping with acute myocarditis based on the revised Lake Louise criteria. Global systolic function was impaired (left ventricular ejection fraction, 48%), with hypokinesis of the basal inferolateral wall (Movies 1, 2). Speckle-tracking echocardiography–based global longitudinal strain demonstrates reduced strain involving most basal segments (global longitudinal strain, −18%) (Fig E). The patient was treated with prednisone, bisoprolol, and colchicine, and symptoms resolved within 10 days.