Influence of Daily Aerobic Exercise Duration on Phase 2 Cardiac Rehabilitation at a Rehabilitation Hospital and Health-Related Quality of Life After Discharge

Background: Phase 2 in-patient cardiac rehabilitation (CR) at a rehabilitation hospital is now added the medical service fees in Japan and in light of the recent reimbursement for CR, a study needed to be performed to determine exertional exercise on its effectiveness and benefits to patients. We examined the effects of daily aerobic exercise duration on health-related quality of life (HR-QoL) at 6 months after discharge from phase 2 CR. Methods: Of the 54 consecutive cardiovascular disease patients admitted to a rehabilitation hospital after acute care, 43 were considered acceptable candidates for enrollment according to predetermined inclusion and exclusion criteria. Of these, 40 patients completed study requirements, including return of a questionnaire on HR-QoL survey 6 months after discharge. The primary outcome was HR-QoL as evaluated using the EuroQol five-dimension five-level (EQ-5D-5L). Two multiple regression models were constructed to assess the influences of daily aerobic exercise duration (content of rehabilitation) and other clinicodemographic variables assessed during acute care (model 1) or at transfer from acute care to a rehabilitation hospital (model 2). Results: Both model 1, which included age, Barthel index of daily function before hospitalization, and daily aerobic exercise duration in the rehabilitation hospital (R 2 = 0.553, P < 0.001), and model 2, which included New York Heart Association functional classification at transfer, Charlson comorbidity index at transfer, and daily aerobic exercise duration (R 2 = 0.336, P = 0.002) identified aerobic exercise duration as a significant independent factor influencing HR-QoL at 6 months post-discharge (model 1: P = 0.041; model 2: P = 0.010). Conclusions: Enhanced daily aerobic exercise content during phase 2 in-hospital CR can significantly improve longer-term HR-QoL among cardiovascular disease patients independently of other clinicodemographic factors, including age, activities of daily living before treatment, and baseline condition at rehabilitation onset. These findings, that in the small sample size, support the continued expansion of phase 2 CR at a rehabilitation hospital in Japan. Cardiol Res. 2023;14(5):351-359 doi: https://doi.org/10.14740/cr1527