Recurrent Heart Failure From Fulminant Giant Cell Myocarditis Following COVID-19 Infection Requiring Heart Transplantation

BACKGROUND: Giant cell myocarditis (GCM) is a rare, rapidly progressive inflammatory cardiomyopathy marked by T cell-mediated myocardial destruction. Early diagnosis is difficult, and outcomes are poor without aggressive treatment. CASE SUMMARY: A 46-year-old woman with recent COVID-19 presented with flulike symptoms and dyspnea. She rapidly decompensated into cardiogenic shock, requiring venoarterial extracorporeal membrane oxygenation. Endomyocardial biopsy revealed fulminant necrotizing myocarditis, prompting treatment with immunosuppressants. She was decannulated and discharged but returned 2 weeks later in shock, again requiring venoarterial extracorporeal membrane oxygenation. She ultimately underwent orthotopic heart transplantation. Explanted pathology confirmed GCM. DISCUSSION: GCM can mimic other forms of myocarditis but requires biopsy for diagnosis. This case underscores the fulminant course of GCM, the utility of early mechanical support, and the importance of prompt recognition.