Predictive factors of a fulminant course in acute myocarditis

Background: Patients who develop fulminant myocarditis often die of sudden cardiac arrest, arrhythmia, or severe heart failure soon after onset if they do not receive percutaneous cardiopulmonary support in time. The purpose of this study was to identify the risk factors of clinical symptoms/signs or laboratory findings that could predict the fulminant course of acute myocarditis. Methods and results: Thirty-five patients (mean age 28 ± 8 years, 17 males) who had been admitted to intensive care unit with the diagnosis of acute myocarditis by clinical presentations were retrospectively recruited. They were divided into the fulminant group (n = 11) and the non-fulminant group (n = 24). Clinical features, laboratory data, and images on admission were analyzed. Overall in-hospital mortality was 17% (6/35). Mortality was higher in the fulminant group (45% vs. 4%, p = 0.027). Multivariate analysis revealed that prolongations of the QRS complex (118 ± 27 vs. 88 ± 10 ms, p = 0.048) and depressed left ventricular ejection fraction (41 ± 7% vs. 57 ± 7%, p = 0.027) were the only independent factors significantly associated with the fulminant course of acute myocarditis. Conclusion: The in-hospital mortality of acute fulminant myocarditis was high. Prolongations of the QRS complex and depressed left ventricular ejection fraction on admission were independent positive predictors for the development of acute fulminant myocarditis.