Fatal rhabdomyolysis and fulminant myocarditis with malignant arrhythmias after one dose of ipilimumab and nivolumab.

Immune checkpoint inhibitors (ICIs) related myocarditis is a rare complication of modern immunotherapy. It can present as an asymptomatic subclinical condition or full-blown fulminant myocarditis with malignant arrythmias and cardiogenic shock. Myositis/rhabdomyolysis and/or myasthenic symptoms can be present concomitantly. We present a case of fatal fulminant myocarditis presenting with cardiac arrythmias and severe systolic dysfunction, with accompanying rhabdomyolysis after the first dose of ipilimumab and nivolumab immunotherapy. First working diagnosis of subacute late presenting acute myocardial infarction (ACS) was incorrect and the correct diagnosis was established only after additional testing and consultation. Treatment consisted of high-dose corticosteroids, intravenous immunoglobulins, sedation with mechanical ventilation, antibiotic coverage, hemodialysis, and sustained low-efficiency daily diafiltration (SLEDD) with CytoSorb or TheraNova membranes, and intra-aortic balloon pump mechanical cardiac support. No tangible improvement in the condition was observed during the whole treatment period and the patient died on the sixth day of intensive care treatment.