Effect of atrial fibrillation on response to exercise-based cardiac rehabilitation in older individuals with heart failure

Background: Although the coexistence of heart failure (HF) with atrial fibrillation (AF) exhibits poor outcomes, the correlation between AF status and outcomes after exercise-based cardiac rehabilitation (CR) remains unclear in older individuals with HF. Objective: This retrospective study aimed to investigate the impact of AF on changes in physical function and prognosis after CR in older individuals with HF. Methods: We enrolled consecutive individuals with HF who were >= 60 years old who received 5-month CR. Exercise-based CR involved moderate-intensity aerobic exercises tailored to each participant. Isometric quadriceps strength (QS) and 6-min walk distance (6MWD) were measured as physical function, at baseline and 5 months thereafter. We compared QS and 6MWD changes from baseline to the 5-month observation period (sicQS and sic6MWD) between sinus rhythm and AF. We examined composite incidence of all-cause death or unplanned readmission after 5-month CR and analysed the association of sicQS and sic6MWD with clinical events, estimating adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). Results: Of the 764 participants, 476 (62%) had sinus rhythm, and 288 (38%) had AF. AF was associated with lower sicQS and sic6MWD at baseline. The 2 groups did not differ in QS and 6MWD after adjusting for clinical confounders. With sinus rhythm, greater change in QS and 6MWD was significantly associated with reduced incidence of clinical events (sicQS tertile: aHR 0.75 [95% CI 0.60-0.92]; sic6MWD tertile: aHR 0.59 [95% CI 0.46-0.76]); however, with AF, this association was observed for only sic6MWD and not QS (sicQS: aHR 0.92 [95% CI 0.72-1.17]; 6MWD: aHR 0.73 [95% CI 0.54-0.98]). Conclusion: AF in older individuals with HF is associated with reduced physical function at baseline but not response to exercise-based CR. Furthermore, positive response of physical function after CR is associated with better prognosis regardless of AF, which suggests that exercise-based CR is potentially effective in older individuals with HF and AF. (C) 2020 Elsevier Masson SAS. All rights reserved.