Management of immune checkpoint inhibitor myocarditis: a serial cardiovascular magnetic resonance T2 mapping approach

A 67-year-old man with advanced renal cell carcinoma presented with a high-grade fever 20 days after his first combination immunotherapy with ipilimumab and nivolumab. Laboratory tests showed elevated cardiac enzymes. Histological samples depicted an intense lymphocytic infiltrate and myocyte necrosis consistent with myocarditis. There was a trend towards more CD8+ cells and positive staining of programmed death ligand 1 (PD-L1) in myocardial tissue (Panels A–C). Based on this confirmed diagnosis of immune checkpoint inhibitors-associated myocarditis, the patient was treated with methylprednisolone, 1 g daily for 3 days, followed by prednisolone, 1 mg/kg/day. The subsequent prednisolone taper, 2.5–10 mg every week, was determined by cardiac troponin levels. The patient underwent four non-contrast cardiovascular magnetic resonance (CMR) studies, with baseline imaging obtained at the onset of myocarditis and follow-up imaging performed at 1, 5, and 9 months intervals (Panels D–G). T2 mapping demonstrated diffusely increased T2...