National Trends, Gender, Management, and Outcomes of Patients Hospitalized for Myocarditis.

Myocarditis is a major cause of acute and chronic cardiomyopathy. Data on patient characteristics utilization of healthcare, and outcomes of myocarditis-related hospitalizations are limited. We sought to analyze the outcomes of patients hospitalized with myocarditis from a large diverse, multicentric, nationwide cohort using Nationwide Inpatient Sample database. A total of 27,129 hospitalizations involving adult patients (age ≥ 18 years) with the primary discharge diagnosis of myocarditis from years 2007 through 2014 were included and patients who had diagnosis of myocardial infarction or coronary syndromes (including unstable angina) during the same hospitalization were excluded. More men were hospitalized compared with women (66% vs 34%, p <0.05). Patients hospitalized were young with a mean age of 37.3 ± 18.8 years with women being older compared with men (45.2 ± 20.9 vs 33.2 ± 16.2, p <0.001). In-hospital complications of cardiogenic shock and ventricular fibrillation/cardiac arrest occurred in 6.5% and 2.5% of hospitalizations, respectively, with females being affected significantly more than males (10.2% vs 4.6%; 3.6% vs 2%, respectively, p <0.001 for both comparisons). A total of 640 (2.4%) patients died during index hospitalization. Mortality was significantly higher in females compared with males (3.5% vs 1.8%; p <0.001). Multiple logistic regression analysis demonstrated female gender as an independent predictor of in-hospital mortality (odds ratio: 1.69, 95% confidence interval: 1.1 to 2.6; p = 0.007). In conclusion, myocarditis-related hospitalizations have increased during the study years and mostly affect young population with no significant co-morbidities. Female gender remains at high risk for myocarditis-related complications and in-hospital mortality.