Association between inpatient cardiac rehabilitation and 30-day readmission in patients with heart failure: Findings from a propensity score-weighted Pseudo-population analysis

BACKGROUND Heart failure (HF) is a major health issue with high hospitalization and 30-day readmission rates. Cardiac rehabilitation (CR) is recommended for managing HF; however, its effectiveness during hospitalization remains unclear in real-world settings. METHODS This retrospective cohort study analyzed data from the National Hospital Organization database in Japan. We included patients with HF aged ≥40 years who were hospitalized between April 2016 and March 2019. We analyzed the relationship between inpatient CR and 30-day outcomes (primary: all-cause readmission) using logistic regression with inverse probability of treatment weighting, which creates a pseudo-population with measured baseline covariates balanced between groups. Propensity score-matched analysis was additionally performed for the primary outcome. RESULTS Among 17,022 eligible patients, 9390 (55.2%) received inpatient CR. Inpatient CR was not significantly associated with lower risks of 30-day all-cause (odds ratio OR: 0.93, 95% confidence interval CI: 0.82-1.05), cardiovascular-related (OR: 0.97, 95%CI: 0.82-1.14), or HF-related readmissions (OR: 0.99, 95%CI: 0.82-1.19), or all-cause death (OR: 0.95, 95%CI: 0.53-1.73) in the weighted analyses. Results for all-cause readmission were consistent in the matched analysis (OR: 0.89, 95%CI: 0.78-1.01). In an exploratory subgroup analysis, inpatient CR was associated with a lower risk of 30-day all-cause readmission among patients without pre-existing kidney dysfunction. Inpatient CR was also significantly associated with improved physical function during hospitalization (OR: 1.18, 95%CI: 1.07-1.31). CONCLUSIONS In this nationwide cohort, inpatient CR was not significantly associated with 30-day readmission risk. However, inpatient CR was associated with improvement in functional status during hospitalization.