Abstract 19280: Gender Disparity in Outcomes of Myocarditis

Introduction: Myocarditis is an inflammatory disorder of cardiac myocytes, which can progress to dilated cardiomyopathy and heart failure. Clinical presentation is highly variable, ranging from subclinical disease to cardiogenic shock and more often affecting men, with a male-to-female ratio of 1.5:1. Women with myocarditis typically have better long-term outcomes than men, including myocardial recovery and transplant free survival. We sought to investigate the difference in in-hospital mortality between men and woman with myocarditis. Methods: The Nationwide Inpatient Sample (NIS), part of the healthcare cost and Utilization Project (HCUP), is the largest publicly available inpatient database designed to provide information on characteristics and outcomes of patients discharged from US hospitals. Using the NIS we identified our study population, composed of all adult patients who were admitted with a primary diagnosis of myocarditis during the calendar years 2008 to 2010. Results: We identified 990 patients with myocarditis, 644 males and 346 females. Women on average were significantly older (48 years vs. 35 years, p <0.001) and had more comorbidities (4.3 vs. 2.7, p <0.001). Women had a significantly higher incidence of shock (13.6 vs. 6.1, p<0.001), longer hospital stays (5.8 days vs. 4.0, p = 0.023) and higher in-hospital mortality (5.2% vs. 2.5%, p = 0.029). After adjusting for pertinent covariates using logistic regression analysis, female gender remained an independent predictor of increased in-hospital mortality (p=0.023, OR=2.384 [1.126-5.048]). Number of chronic conditions also independently predicted higher in-hospital mortality (p=0.000, OR=1.309 [1.174-1.461]). Presence of hypertension exhibited a protective effect (p=0.004, OR=0.048 [0.006-0.371]). Conclusion: In patients admitted with myocarditis, women were significantly older at presentation and had more comorbidities, but after adjusting for these clinical variables, they still had significantly higher in-hospital mortality compared to men.