Effect of different intensity exercises on cardiopulmonary function and quality of life of patients with chronic heart failure : Asystematic review and meta-analysis.

Abstract

Exercise-based cardiac rehabilitation has positive benefits for patients with chronic heart failure (CHF), but the choice of exercise intensity has been controversial. The aim of this systematic review and meta-analysis was to investigate the effects of different exercise intensities on cardiopulmonary function and quality of life (QoL) of patients with CHF. Randomized controlled trials (RCTs) of different exercise intensities applied to patients with CHF were searched in PubMed, Web of Science, the Cochrane Library, and Embase databases from inception to December 2021. Study selection and data extraction were performed simultaneously by two independent reviewers, using the Physiotherapy Evidence Database Scale (PEDro) for quality assessment of the included literature. The weighted mean differences (WMD) or standardized mean difference (SMD) were calculated by employing afixed or random effects model. Other statistical analyses included subgroup analysis and sensitivity analysis. Quality of evidence was evaluated by the Grade of Recommendation, Assessment, Development, and Evaluation (GRADE) method. Eight RCTs were included. Analyses reported no significant improvement in left ventricular ejection fractions (LVEF; WMD = 0.47, 95% CI [-4.10, 5.03], p = 0.841), peak oxygen uptake (peakVO2) (SMD = 0.38, 95% CI [-0.03, 0.80], p = 0.069) and 6‑min walking distance (6MWD) (WMD = 14.10, 95% CI [-9.51, 37.72], p = 0.242). Exercise interventions of varying intensity produced small-to-moderate beneficial effects on QoL (WMD = -4.99, 95% CI [-8.29, -1.68], p = 0.003), which appeared to be attenuated at long-term follow-up (WMD = 2.12, 95% CI [-2.91, 7.16], p = 0.409). High-intensity exercise does not have asignificant advantage over moderate-intensity exercise in improving cardiopulmonary function and aerobic capacity in patients with CHF. Beneficial changes in QoL from high-intensity exercise also appeared to decrease during long-term follow-up, indicating acumulative effect of the efficacy of high-intensity exercise.