The effectiveness of functional electrical stimulation of the legs in patients with heart failure: A systematic review and meta-analysis of randomized controlled trials

Abstract

Objective

To investigate the effectiveness of functional electrical stimulation of the legs in patients with heart failure.

Methods

Data were obtained from PubMed, Cochrane Library, and Embase databases until August 12, 2021. We included randomized controlled trials that evaluated the effects of functional electrical stimulation applied to the legs of patients with heart failure, namely changes in cardiopulmonary function, muscle strength, and quality of life.

Results

In total, 14 randomized controlled trials (consisting of 518 patients) were included in our article. Pooled estimates demonstrated that functional electrical stimulation significantly improved peak oxygen consumption (peak VO₂; standardized mean difference = 0.33, 95% confidence interval = 0.07–0.59, eight randomized controlled trials, n = 321), 6-min walking distance (mean difference = 48.03 m, 95% confidence interval = 28.50–67.57 m, 10 randomized controlled trials, n = 380), and Minnesota Living with Heart Failure Questionnaire quality of life score (mean difference =  − 8.23, 95% confidence interval =  − 12.64 to − 3.83, nine randomized controlled trials, n = 383). Muscle strength of lower extremities was not significantly improved in the functional electrical stimulation group compared with that in the control group (standardized mean difference = 0.26, 95% confidence interval =  − 0.18 to 0.71, five randomized controlled trials, n = 218). Furthermore, the subgroup analysis revealed that functional electrical stimulation significantly improved peak VO₂, 6-min walking distance, and Minnesota Living with Heart Failure Questionnaire quality of life score in the heart failure with reduced ejection fraction and heart failure with preserved ejection fraction subgroups.

Conclusion

Functional electrical stimulation can effectively improve the cardiopulmonary function and quality of life in patients with heart failure. However, functional electrical stimulation did not significantly improve muscle strength in the legs.