Clinical outcome after acute coronary syndrome in Japanese patients: An observational cohort study

SummaryBackgroundMortality and morbidity after acute coronary syndrome (ACS) in Japan appear to be different from those in Western countries due to different social healthcare systems, races, geographical locations, and interventional procedures, although data are limited in Japan.MethodsWith a hospital-based cohort study comprising all the new patients who had visited our hospital between 2004 and 2007 (n = 6562), we identified all-cause mortality, the composite endpoint of cardiac death, non-fatal myocardial infarction (MI), or target vessel revascularization and the predictors.ResultsOf the total, 293 patients were included with a discharge diagnosis of ACS (median follow-up of 24.5 months). Non-ST elevation-ACS (NSTE-ACS) (unstable angina and non-ST elevation MI) and ST elevation MI (STEMI) were observed in 165 (56.3%) and 128 (43.7%) patients, respectively. Percutaneous coronary intervention or coronary artery bypass graft surgery was performed in 72.7% and 14.5% of NSTE-ACS patients, respectively and in 82.8% and 10.2% of STEMI patients. The use of aspirin, ticlopidine, and beta-blockers for NSTE-ACS patients were 93.3%, 66.9%, and 38.0%, respectively, with corresponding rates of 96.0%, 75.4%, and 57.1% for STEMI patients. All-cause mortality rates in NSTE-ACS and STEMI were 1.8% and 5.5% at 30 days, respectively, and 6.3% and 12.9% at 2 years, with corresponding rates of 3.7% and 8.7% at 30 days, respectively, and 23.4% and 35.6% at 2 years for the composite endpoint. Multivariate analysis showed that predictors for mortality were older age (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.018–1.244) and estimated glomerular filtration rate value (HR 0.96, 95% CI 0.929–0.988) in NSTE-ACS, and older age (HR 1.10, 95% CI 1.011–1.119) and congestive heart failure on admission (HR 20.0, 95% CI 2.439–164.4) in STEMI.ConclusionsThe present study identified long-term mortality, morbidity, and predictors of adverse events for Japanese patients with ACS.