Checkpoint inhibitor myocarditis with preceding immunosuppression and tolerance of sequential anthracycline therapy

A man in his 50s with no known cardiac history and diffuse large B-cell lymphoma on nivolumab presented with acute dyspnoea and swelling. Physical examination revealed volume overload. Work-up noted new elevation of B-type natriuretic peptide and troponin, with new lateral T-wave inversions on ECG. He was admitted to cardiac intensive care for decompensated heart failure. Echocardiography showed ejection fraction 51% with diffuse hypokinesis and reduction of global longitudinal strain. Cardiac MRI demonstrated diffuse myocardial fibrosis with oedema suggesting acute injury. Endomyocardial biopsy revealed lymphocytic and macrophagic infiltrate with cardiomyocyte damage, compatible with immune checkpoint inhibitor (ICI) myocarditis. Immunotherapy was discontinued and he was treated with diuresis, steroids and initiation of goal-directed medical therapy for heart failure. He required additional treatment with anthracyclines. He was monitored with cardio-oncology follow-up after every cycle of anthracycline and tolerated a cumulative 312 mg/m² therapy. The safety of anthracycline administration after ICI-myocarditis has not been described.