Post SARS-CoV-2 Myocarditis: Giant Cell or MIS-A? A Misdiagnosis Leading to a Heart Transplantation.

BACKGROUND

Giant cell myocarditis (GCM) and multisystem inflammatory syndrome in adults (MIS-A) with myocarditis that appears after SARS-CoV-2 infection (COVID-19) may manifest similarly.

CASE SUMMARY: We describe a patient with GCM who presented with cardiogenic shock and received a misdiagnosis of MIS-A myocarditis because of a lack of giant cells identified on endomyocardial biopsy (EMB). Her cardiac function improved with combined immunosuppressive therapy, including cyclosporine, but subsequently worsened, with premature cessation of immunosuppression resulting from the misdiagnosis. The patient received a heart transplant. Pathologic examination of the explanted heart confirmed the diagnosis of necrotizing GCM.

DISCUSSION: The diagnosis of GCM is challenging given the limited sensitivity of EMB. Treatment includes prolonged calcineurin-based combined immunosuppression, and early cessation of treatment can lead to fatal relapse.

TAKE-HOME MESSAGE: COVID-19 may cause delayed myocarditis, and high clinical suspicion for GCM is crucial to inform appropriate management and increase the likelihood of survival.