Major cardiovascular events in Japanese patients with acute and chronic coronary syndrome

BACKGROUND: Cardiovascular (CV) disease remains the second leading cause of mortality in Japan, yet real-world estimates of recurrent CV risk across acute coronary syndrome (ACS) and chronic coronary syndrome (CCS) phenotypes are limited. We quantified recurrent CV risk and characterised high-risk subgroups in Japanese patients with ACS and CCS. METHODS AND RESULTS: This retrospective cohort study used the Medical Data Vision claims database. Patients with ACS or CCS were followed from cohort entry to the first composite CV endpoint or end of data. The primary composite endpoint included all-cause death, myocardial infarction or stroke. The secondary composite endpoint included the primary endpoint plus hospitalisation for unstable angina, hospitalisation for heart failure or emergent or elective coronary revascularisation. Baseline clinical characteristics were evaluated as predictors. Time-to-event analyses were conducted.26 656 and 16 172 patients were included in the ACS and CCS cohorts, respectively. Median follow-up was 3.0 years in the ACS cohort and 3.2 years in the CCS cohort. The 1-year risk of the primary endpoint was 17.7% in first-time ACS, 8.0% in prior ACS and 5.3% in CCS; corresponding 5-year risks were 24.0%, 13.8% and 12.0%, respectively. In CCS, elderly men with prior ACS, heart failure, diabetes mellitus and chronic kidney disease had a 23.0% 1-year risk of the primary endpoint. CONCLUSIONS: Recurrent CV risk was highest after a first ACS event and was heterogenous in CCS, with substantially higher risk in comorbidity-burdened subgroups. These findings provide contemporary real-world estimates of recurrent CV risk and support further refinement and validation of risk-stratification approaches for secondary prevention.