Associations between kidney function and outcomes of comprehensive cardiac rehabilitation in patients with heart failure.

To investigate the impact of baseline kidney function on outcomes following comprehensive cardiac rehabilitation (CR) in patients with heart failure (HF). We reviewed a total of 3,727 patients who were admitted for HF treatment. Estimated glomerular filtration rate (eGFR), quadriceps strength (QS), and 6-min walk distance (6MWD) were measured at hospital discharge as a baseline and 5 months thereafter in participants of outpatient comprehensive CR. The association between outpatient CR participation and all-cause events was evaluated using propensity score-matched analysis in subgroups across eGFR stages. The changes in QS and 6MWD following 5-month CR were compared between eGFR stages. Out of the studied patients, 1585 (42.5%) participated in outpatient CR. After propensity matching for clinical confounders, 2680 patients were included for analysis (pairs of n = 1340 outpatient CR participants and nonparticipants). The participation in outpatient CR was significantly associated with low clinical events in subgroups of eGFR ≥ 60 [hazard ratio (HR): 0.65, 95% confidence interval (CI): 0.51–0.84] and eGFR 45–60 (HR: 0.71, 95% CI: 0.55–0.92), but not in eGFR 30–45 (HR: 0.83, 95% CI: 0.64–1.08) and eGFR < 30 (HR: 0.88, 95% CI: 0.69–1.12). QS and 6MWD were significantly higher after 5-month CR than those at baseline (P < 0.001, respectively), but lower baseline eGFR correlated with lower changes in QS and 6MWD (trend P < 0.001, respectively). Although low baseline kidney function attenuates the outcomes of CR, outpatient CR seems to be associated with a better prognosis and positive change in physical function in HF patients with low kidney function.