Abstract
Background The correlation between severity and long-term outcomes of pediatric myocarditis have been reported, however this correlation in adults has rarely been studied. Materials and Methods This nationwide population-based cohort study used data from the National Health Insurance Research Database in Taiwan. Patients aged < 75 and > 18 years admitted to an intensive care unit due to acute myocarditis were enrolled and divided into three groups according to mechanical circulatory support (MCS) after excluding major comorbidities. All-cause mortality, cardiovascular death, and heart failure hospitalization were evaluated from January 1, 2001 to December 31, 2011. Results There were 1145 patients with acute myocarditis (mean age 40.2 years, SD: 14.8 years), of which 851 did not require MCS, 99 underwent intra-aortic balloon pump (IABP) support, and 195 extracorporeal membrane oxygenation (ECMO) support. There was no significant difference in heart failure hospitalization between the three groups after index admission. The incidence of cardiovascular death after discharge ranged from 10 % to 22%, which was highest in the ECMO group, and was also significantly different between the three groups within 3 months (p<0.001) but it disappeared after 3 months (p=0.458). The trend was also noted in incidence of all-cause mortality. Conclusions The severity of acute myocarditis did not affect long-term outcomes, however, it was associated with cardiovascular/all-cause death within 3 months after discharge.