Participation and Prognostic Impact of Cardiac Rehabilitation After Acute Coronary Syndrome: Big-Data Study of the Korean National Health Insurance Service

BACKGROUND: To investigate the actual rate and quality of cardiac rehabilitation (CR) participation in South Korea and its short-term impact on clinical outcomes after acute coronary syndrome (ACS). METHODS: Data, including confirmed ACS diagnosis, socio-demographics, comorbidities, clinical outcomes, and CR claim codes, were collected from the Korean National Health Insurance Service claims database and compared between the CR and non-CR groups. RESULTS: Overall, 102,544 patients were included in the study, of which only 5.8% attended CR. Regarding testing, 83.6% of CR patients performed the cardiopulmonary exercise test, but follow-up testing was infrequently performed; in addition, 53.1% of them participated in an electrocardiogram monitoring exercise, but over half participated in only one session. After 1:1 propensity score matching, post-ACS cardiovascular events were significantly lower in the CR group than in the non-CR group. The cumulative 3-year hazard ratio for all-cause death was 0.612 (95% confidence interval [CI], 0.495–0.756), recurrent ACS was 0.92 (95% CI, 0.853–0.993), CR readmission was 0.817 (95% CI, 0.768–0.868), and major adverse cardiovascular events (MACE) was 0.827 (95% CI, 0.781–0.874) in the CR group. CR was associated with a significant dose-response effect on MACE, with a reduction in incidence from 0.854 to 0.711. CONCLUSION: The actual rate of CR participation in South Korea remains low, and participation quality was not outstanding despite National Health Insurance coverage. Nevertheless, the impact of CR on cardiovascular outcomes after ACS was significantly superior. Efforts to increase CR participation should be increased by establishing new CR facilities and strategies to resolve associated barriers.