Comparison of Inpatient and Outpatient Cardiac Rehabilitation Following Myocardial Infarction

<b>Background:</b> Models of second-phase cardiac rehabilitation (CR) following myocardial infarction (MI) differ across countries. The aim of this study was to compare outcomes in MI survivors participating in outpatient and inpatient CR programs. <b>Methods:</b> All patients hospitalized for acute MI in Poland between October 2017 and December 2018 (n = 96,634) were included in the study. Among them, 4411 patients were referred to and commenced outpatient CR, whereas 11,626 patients started inpatient CR within 30 days following discharge. <b>Results:</b> The mean follow-up period was 332.8 ± 128.1 days. Younger age, male sex, and a history of cancer were associated with a higher probability of participating in outpatient CR, whereas diabetes, heart failure, chronic kidney disease, chronic obstructive pulmonary disease, ST-elevation MI, and myocardial revascularization were associated with a lower likelihood of outpatient CR participation. Participation in outpatient CR was linked to a reduced risk of all-cause mortality, in both univariable (hazard ratio [95% confidence interval]: 0.37 [0.26-0.51]) and multivariable analyses (0.53 [0.38-0.74]). Outpatient CR was also associated with a lower risk of death, MI, or stroke (0.57 [0.48-0.67] in univariable analysis and 0.72 [0.61-0.84] in multivariable analysis), as well as a lower risk of death or cardiovascular hospitalization (0.78 [0.73-0.84] and 0.85 [0.80-0.91], respectively). <b>Conclusions:</b> Outpatient CR following MI tends to occur alongside a better prognosis compared to inpatient programs.