日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

Coronavirus disease 2019 vaccine-associated myocarditis (C-VAM) is a rare complication, but it has been reported and has attracted attention from various countries. C-VAM occurrences may increase with the rise in the number of people vaccinated. Here, we report a case of C-VAM with persistent abnormal findings on cardiac magnetic resonance imaging (CMR) for one year after disease onset. A 14-year-old male patient presented with fever and chest pain after receiving the second dose of the coronavirus mRNA vaccine. Electrocardiogram (ECG) changes, elevated serum troponin I level, and abnormal CMR findings indicated C-VAM diagnosis. The acute phase was very mild which improved in a few days with symptomatic treatment alone; however, the ECG normalized after more than a month, and abnormal findings on late gadolinium enhancement (LGE)-CMR remained one year after disease onset. The long-term prognosis of C-VAM remains unclear. Residual LGE findings in non-C-VAM acute myocarditis have been associated with long-term prognosis. Therefore, long-term follow-up is necessary for C-VAM despite the mild clinical course of the acute phase.