Multidisciplinary diagnostic approach for fulminant myocarditis related to coronavirus disease 2019 messenger RNA vaccines: a case report

Background Recent reports have raised serious concerns regarding acute myocarditis related to coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccines. There are only a few reports of fulminant lymphocytic myocarditis that developed after vaccination. Although the diagnostic approach varied among them, no cases with multidisciplinary diagnostic approaches, including cytokine analysis, have been reported. Case summary A 59-year-old male with no medical history complained of chest pain a day after receiving the first dose of COVID-19 mRNA (BNT162b2) vaccination. On hospital Day 3, he developed a refractory cardiogenic shock and pulseless ventricular tachycardia, requiring mechanical circulatory support secondary to an exacerbation of myocarditis. Based on the clinical course and examination results, including histologic findings showing a diffuse lymphocytic inflammatory infiltrate with abundant T cells and macrophages in the myocardium, and cardiac magnetic resonance (CMR) findings showing a high-intensity signal on the T2-weighted image and late gadolinium enhancement, he was diagnosed with fulminant myocarditis related to COVID-19 mRNA vaccination. His haemodynamic status gradually improved without immunosuppressive or anti-inflammatory therapy, and he was discharged from hospital on Day 47. To investigate the pathogenesis, we performed cytokine analysis, which showed an increase in serum IP-10, MCP-3, and MIG concentrations, suggesting that Th1-type chemokines preferentially promote cellular immunity. Discussion In the present case of a patient with fulminant myocarditis following COVID-19 mRNA vaccination diagnosed through histopathological and CMR findings, additional cytokine analysis revealed that elevated levels of cytokines pertaining to Th1 immune response may be involved in disease pathogenesis. A multidisciplinary diagnostic approach is crucial not only to comprehend an individual patient's condition but also to clarify the disease pathogenesis.