Improved Peak Oxygen Uptake Reduces Cardiac Events After 3 Weeks of Inpatient Cardiac Rehabilitation for Chronic Heart Failure Patients.

Background: The incidence of heart failure (HF) is increasing, and the mortality from HF remains high in an aging society. Cardiac rehabilitation (CR) programs (CRP) increase oxygen uptake (V̇O₂) and reduce HF rehospitalization and mortality. Therefore, CR is recommended for every HF patient. However, the number of outpatients undergoing CR remains low, with insufficient attendance at CRP sessions. In this study we evaluated the outcomes of 3 weeks of inpatient CRP (3w In-CRP) for HF patients. Methods and Results: This study enrolled 93 HF patients after acute-phase hospitalization between 2019 and 2022. Patients participated in 30 sessions of 3w In-CRP (30 min aerobic exercise twice daily, 5 days/week). Before and after 3w In-CRP, patients underwent a cardiopulmonary exercise test, and cardiovascular (CV) events (mortality, HF rehospitalization, myocardial infarction, and cerebrovascular disease) after discharge were evaluated. After 3w In-CPR, mean (±SD) peak V̇O₂ increased from 11.8±3.2 to 13.7±4.1 mL/min/kg (116.5±22.1%). During the follow-up period (357±292 days after discharge), 20 patients were rehospitalized for HF, 1 had a stroke, and 8 died for any reasons. Proportional hazard and Kaplan-Meier analyses demonstrated that CV events were reduced among patients with a 6.1% improvement in peak V̇O₂ than in patients without any improvement in peak V̇O₂. Conclusions: 3w In-CRP for HF patients improved peak V̇O₂ and reduced CV events in HF patients with a 6.1% improvement in peak V̇O₂.