Background: Functional electrical stimulation (FES) improves exercise capacity, quality of life, emotional stress, and endothelial function in chronic heart failure with impaired systolic function. We sought to investigate the effects of FES on the above parameters in patients with preserved ejection fraction (HFpEF).
Methods: Thirty HFpEF patients, 18 female and 12 male, aged 69 ± 8 years, in New York Heart Association class II or III and with mean ejection fraction 63% ± 6%, were randomly (1:1) assigned to a 6-week FES program or placebo. Assessment was performed at baseline and after completion of training protocol and included 6-minute walked distance, quality of life (Kansas City Cardiomyopathy Questionnaire and Minnesota Living with Heart Failure Questionnaire), depressive symptoms (Beck Depression Inventory and Zung self-rated depression scores), B-type natriuretic peptide, endothelial function (flow-mediated dilatation), and left ventricular diastolic function.
Results: A significant improvement in 6-minute walked distance (F = 21.61, P = .001), Kansas City Cardiomyopathy Questionnaire summary (F = 8.68, P = .006), Minnesota Living with Heart Failure Questionnaire (F = 6.43, P = .017), Beck Depression Inventory (F = 6.66, P = .015), Zung (F = 6.25, P = .019), and flow-mediated dilatation diameter (F = 11.98, P = .002) was observed in the FES group compared with placebo group; B-type natriuretic peptide also declined but not significantly (F = 0.249, P = .622), and there was a tendency toward lower mitral E/e' wave ratio (F = 3.066, P = .091).
Conclusion: As in heart failure and reduced left ventricular ejection fraction, FES also improves exercise capacity, quality of life, emotional status, and endothelial function in HFpEF. Given the lack of effective evidence-based therapies in these patients, FES warrants further investigation.
Trial registration: ClinicalTrials.gov NCT01829607.