The effect of functional electrical stimulation of the legs on cardiopulmonary function and quality of life in patients with chronic heart failure: A systematic review and meta-analysis

Abstract

Introduction: Functional electrical stimulation is important for the rehabilitation of patients with chronic heart failure. This meta-analysis of randomized controlled trials compared the efficacy of functional electrical stimulation versus conventional exercise training or placebo in patients with chronic heart failure. Methods: Studies were searched through PubMed, Embase, and the Cochrane Library databases up to 1 November 2023. The outcomes were cardiopulmonary function index (6-minute walking distance), peak oxygen consumption, and Minnesota Heart Failure Life Questionnaire quality of life scores. A subgroup analysis was conducted according to the ejection fraction. The 95% confidence interval and mean difference represented the outcome of the effect size. Results: Seventeen studies involving 732 participants were included. Compared with the control, functional electrical stimulation significantly improved peak oxygen consumption (MD = 2.84 ml/kg/min, 95% Cl: 1.99–3.68 ml/kg/min), increased 6-minute walking distance (MD = 49.52 m, 95% Cl: 22.61–76.43 m), and improved the life quality scores (MD = −12.86, 95% Cl: −17.48 to −7.88). Compared with functional electrical stimulation, exercise training also improved peak oxygen consumption (MD = −0.94 ml/kg/min −1 , 95% Cl: −1.36 to −0.52 ml/kg/min), and the quality of life (QoL, MD = 0.66, 95% Cl: 0.34–0.98, p < 0.05, I 2 = 38%), but the result of 6-minute walking distance (MD = −6.97 m, 95% Cl: −18.32 to −4.38 m) did not show a difference. Further subgroup analysis showed that outcomes including the above, significantly improved under the functional electrical stimulationfor both HF patients with reduced ejection fraction and HF patients with preserved ejection fraction patients, but difference is insignificant of the results between groups of aerobic exercise and functional electrical stimulationacted on patients with HF patients with reduced ejection fraction. Conclusions: Our study demonstrates that compared with placebo, functional electrical stimulation benefits the patients with chronic heart failure on cardiopulmonary function and quality of life. Furthermore, HF patients with reduced ejection fraction patients benefit more from functional electrical stimulation than HF patients with reduced ejection fraction patients. Therefore, functional electrical stimulation is a promising complementary therapy for patients with chronic heart failure.