Abstract Background Hospital-associated disability (HAD), a decline in the ability to perform activities of daily living (ADL) during hospitalization, is a modifiable target in the integrated care for older adults. Inpatient rehabilitation during the perioperative period is a part of a comprehensive cardiac rehabilitation (CR) program and plays a pivotal role in functional recovery and smooth reintegration into the home, community, and workplace after surgery. Prior research, including meta-analyses, have shown that outpatient CR participation after discharge of patients who underwent transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement is associated with a significant improvement in exercise capacity and indexes of ADL. However, the impact of inpatient CR on the occurrence of HAD remains unexplored. Purpose Using a large real-world nationwide database in Japan, the aim of this study was to determine the prevalence of HAD and the impact of inpatient CR participation on the development of HAD in older patients undergoing TAVI. Methods Older patients undergoing TAVI were extracted from the Japanese nationwide database (JROAD-DPC) from April 2014 to March 2021 and were divided into patients receiving inpatient CR (CR group) and non-CR group. HAD was defined as a decrease in the Barthel Index score ≥ 5 points at discharge relative to admission. Results Of 19,789 eligible patients, 17,066 (86%) underwent inpatient CR (average age, 84.3 ± 4.9 years; Woman, 65%). The overall prevalence of HAD was 9.6%, with a lower incidence in the CR group than those in the non-CR group (8.8% vs. 14.2%, p < 0.01). Participation in inpatient CR was associated with a significantly lower odds ratio (OR) of HAD in multivariate logistic regression analysis (adjusted OR, 0.62; 95% confidence interval [CI], 0.54–0.70; p < 0.01) and in inverse probability of treatment weighting-adjusted logistic regression analyses (adjusted OR, 0.82; 95% CI, 0.77–0.88; p < 0.01; Table). Analyses in subgroups of interest showed heterogeneity of the effects of inpatient CR with possible loss in patients with a body mass index of less than 18.5 kg/m² or BI score of less than 60 points at admission (Figure). Conclusions A substantial number of older patients undergoing TAVI developed HAD during perioperative period. Participation in inpatient CR was associated with a lower likelihood of HAD in TAVI recipients, but the benefit of inpatient CR for development of HAD was possibly lost in patients with a low BMI and low a BI score at admission, indicating the necessity of HAD-targeted multidisciplinary CR for lean patients with ADL disability before TAVI.Figure