Ammirati E, et al. - In this retrospective, international registry comprising 16 tertiary hospitals in the United States, Europe, and Japan, researchers provided additional evidence on the fulminant myocarditis (FM), a form of acute myocarditis characterized by severe systolic left ventricular dysfunction that requires inotropic and/or mechanical circulatory support, outcome and whether patient stratification based on the main histologic subtypes can provide additional prognostic information. The study sample consisted of 220 patients (median age 42 years) with histologically proven acute myocarditis (onset of symptoms <30 days) all presenting with left ventricular systolic dysfunction. Compared to patients with nonfulminant myocarditis, patients with FM have higher rates of cardiac death and heart transplantation both in the short- and long-term. In addition, the histologic FM subtype has an independent prognostic value, underlining the need for timely endomyocardial biopsy in this condition.