Current Status and Effect of Outpatient Cardiac Rehabilitation After Percutaneous Coronary Intervention in Japan.

Background: Although cardiac rehabilitation (CR) has been reported to be associated with better clinical outcomes in patients with cardiovascular diseases, there are few nationwide studies about CR participation by patients with coronary artery disease in Japan. Methods and Results: We performed a nationwide retrospective cohort study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan between April 2014 and March 2018. Patients were divided into 2 groups (acute coronary syndrome [ACS] and stable coronary artery disease [sCAD]), and the rates of participation in in- and outpatient CR after percutaneous coronary intervention (PCI) were investigated. Propensity score-matched analysis was performed and the association between outpatient CR participation and all-cause mortality 3 months after PCI was examined. Overall, 616,664 patients (ACS, n=202,853; sCAD, n=413,811) were analyzed. The participation rates of CR increased annually. The participation rate was higher for inpatient than outpatient CR in both the ACS (52% vs. 9%, respectively) and sCAD (15% vs. 3%, respectively) groups. Prognosis was better for patients with than without outpatient CR in both the ACS (hazard ratio [HR] 0.52; 95% confidence interval [CI] 0.47-0.59) and sCAD (HR 0.72; 95% CI 0.65-0.80) groups. Conclusions: Outpatient CR was associated with a better prognosis in patients with ACS or sCAD. The participation rates of outpatient CR following PCI were extremely low in Japan.