The effect of functional electrical stimulation on cardiopulmonary function and quality of life in heart failure - a systematic review and meta-analysis

Abstract Background Patients with Heart Failure often report symptoms such as increased breathlessness and fatigue, due to decreased cardiopulmonary function, and as a result also report a reduced quality of life. Conventional aerobic exercise training (AT) works to combat these symptoms by increasing blood flow to the muscles and reversing the muscle weakness/myopathy caused by reduced blood flow, however it has poor adherence. Functional electrical stimulation (FES) can be used as an alternative type of exercise training for those patients who unable to undertake AT. Aims To identify whether FES impacts on cardiopulmonary function measured objectively by the 6-minute walk distance test and peak VO2. To identify the impact of FES on quality of life, measured objectively by The Minnesota Living with Heart Failure Questionnaire and The Kanas City Cardiomyopathy Questionnaire. Method A systematic search for peer-reviewed randomised control trials from 2000 to present was completed via Medline, Embase, Cochrane Library, Scopus, PubMed, AMED, and ClinicalTrials.gov. Papers were exported onto ENDNOTE for duplicate, abstract and title, and full text screening. Then a meta-analysis was conducted via the use of STATA/SE. Results In total, 24 randomised control trials were included in this systematic review and meta-analysis. Pooled analysis demonstrated that FES significantly improved the 6MWD and Quality of life compared to control and SHAM-FES, showing no significant effect on peak VO2. Aerobic training was superior to FES in terms of 6MWD and peak VO2, but no significant difference was found for quality of life. Conclusion This review demonstrates that, compared with control, FES benefits heart failure patients on cardiopulmonary function and quality of life, and is suitable for use in patients who cannot tolerate conventional aerobic training. Highlighted in this study, is the need for further research around FES in heart failure with preserved ejection fraction, and the use of FES as an adjunct therapy to conventional aerobic training.