Fatal giant cell myocarditis in a patient with multiple autoimmune disorders

A case of circulatory collapse due to severe heart failure is reported in a 52-year old male with autoimmune disorders in the form of type-1 diabetes, Graves' disease and total alopecia. Upon admission, the patient had severe heart failure with a cardiac index of 0.9 l/min/m², a mixed venous saturation of 29% and left ventricular ejection fraction of 5%. The condition was refractory to treatment with inotropic agents and required mechanical cardiopulmonary support. Endomyocardial biopsies revealed extensive giant cell myocarditis (GCM). Immunosuppressant treatment did not alter the condition and urgent orthotopic heart transplantation was performed. Histopathological examination of the explanted heart confirmed the diagnosis and showed widespread vascular deposition of complement C4d suggesting a pathogenic role for the innate immune system in GCM. At 1-year follow-up the patient was in New York Heart Association (NYHA) class I, had episodes of sustained ventriular tachycardia but showed no evidence of GCM recurrence in endomyocardial biopsies.