Nivolumab-induced Myocarditis Successfully Treated with Corticosteroid Therapy: A Case Report and Review of the Literature

Matsuo, Keisuke; Ishiguro, Takashi; Najama, Takatomo; Shimizu, Yoshihiko; Kobayashi, Yasuhito; Mutou, Makoto

From hospital day 4, the internal corticosteroid dose (prednisolone) was reduced to 60 mg daily (1 mg/kg). The patient's condition subsequently improved. His serum creatine kinase value decreased to the normal range within a week after admission. The ejection fraction measured by the transthoracic cardiac ultrasound examination performed on hospital day 9 improved to 55%, and asynergy of the car- diac wall also improved. Electrocardiography performed on hospital day 10 showed narrowing of the QRS. CMR imaging was performed on hospital day 11 and one month following the start of methylprednisolone administration. Cine images showed gradual improvement of the wall motion abnormality with recovery of the left ventricular ejection fraction. T2w-STIR-BB and EGE images showed improvement of edema findings, and late gadolinium enhancement of the myocardium was decreased. The patient was discharged on hospital day 19. After discharge, the corticosteroid dose was gradually tapered (prednisolone 60 mg daily for 1 week, 50 mg daily for 2 weeks, 40 mg daily for 2 weeks, and 30 mg daily thereafter), and he has been regularly followed up on an outpatient basis. He continues to take prednisolone 30 mg daily, and his myocarditis has not recurred.