BackgroundOwing to an increasing aging population, the number of elderly patients undergoing percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) is escalating. The onset of STEMI in elderly patients may lead to increased frailty, resulting in failure of discharge to home despite survival. However, the association of discharge destination with prognosis has not been fully evaluated in this population. MethodsBetween January 2014 and December 2016, a total of 245 octogenarian STEMI survivors who underwent PCI (mean age, 84.4 years; male, 46.5%) were evaluated from a multicenter registry. The 2-year mortalities of the home discharge and non-home discharge groups were compared and analyzed using a Cox regression model. ResultsNon-home discharge, which was defined as transfer to another hospital or nursing home after STEMI, was seen in 36 patients. During the 2 years, 37 patients died (home discharge, 27 patients; non-home discharge, 10 patients). The most frequent cause of death was due to infection (21.6%), followed by sudden death (18.9%) and heart failure (16.2%). The cumulative all-cause mortality was significantly higher in the non-home discharge group than in the home discharge group [36.4% vs. 14.8%; hazard ratio (HR), 2.95; 95% confidence interval (CI), 1.43−6.10; p = 0.003]. After multivariate analysis, non-home discharge (adjusted HR, 2.62; 95% CI, 1.20−5.75; p = 0.016) together with left ventricular ejection fraction <40% (adjusted HR, 3.15; 95% CI, 1.57−6.31; p = 0.001), prior heart failure (adjusted HR, 4.88; 95% CI, 1.82−13.13; p = 0.002), target lesion in the left anterior descending artery (adjusted HR, 2.20; 95% CI, 1.12−4.32; p = 0.022), and serum albumin level <3.5 g/dL (adjusted HR, 2.13; 95% CI, 1.06−4.27; p = 0.034) remained significant predictors of all-cause mortality. ConclusionNon-home discharge was associated with an increased risk of mid-term mortality in octogenarian STEMI survivors.