Impact of and Reasons for Not Performing Exercise Training After an Acute Coronary Syndrome in the Setting of an Interdisciplinary Cardiac Rehabilitation Program: Results From a Risk-Op- Acute Coronary Syndrome Ambispective Registry

Background and Aims: Exercise training (ET) is a critical component of cardiac rehabilitation (CR), but it remains underused. The aim of this study was to compare clinical outcomes between patients who completed ET (A-T), those who accepted ET but did not complete it (A-NT), and those who did not accept to undergo it (R-NT), and to analyze reasons for rejecting or not completing ET. Methods and Results: A unicenter ambispective observational registry study of 497 patients with acute coronary syndrome (ACS) was carried out in Barcelona, Spain, from 2016 to 2019. The primary endpoint was a composite of all-cause mortality, hospitalization for ACS, or need for revascularization during follow-up. Multivariable analysis was carried out to identify variables independently associated with the primary outcome. Initially, 70% of patients accepted participating in the ET, but only 50.5% completed it. The A-T group were younger and had fewer comorbidities. Baseline characteristics in A-NT and R-NT groups were very similar. The main reason for not undergoing or completing ET was rejection (reason unknown) or work/schedule incompatibility. The median follow-up period was 31 months. Both the composite primary endpoint and mortality were significantly lower in the A-T group compared to the A-NT and R-NT (primary endpoint: 3.6% vs. 23.2% vs. 20.4%, p < 0.001, respectively; mortality: 0.8% vs. 9.1% vs. 8.2%, p < 0.001; respectively). During multivariable analysis, the only variables that remained statistically significant with the composite endpoint were ET completion, previous ACS, and anemia. Conclusion: Completion of ET after ACS was associated with improved prognosis. Only half of the patients completed the ET program, with the leading reasons for not completing it being refusal (reason unknown) and work/schedule incompatibility. These results highlight the need to focus on the needs of patients in order to guarantee that structural barriers to ET no longer exist.