Functional electrical stimulation in the treatment of patients with chronic heart failure: a meta-analysis of randomized controlled trials.

Functional electrical stimulation (FES) produces beneficial effects in the treatment of patients with chronic heart failure (CHF), but studies carried out in these patients show small sample sizes and conflicting results. The aim of this meta-analysis was to systematically review the effect of treatment with FES compared with conventional aerobic exercise training (CA) or control group in patients with CHF. The search strategy included MEDLINE, LILACS, Physiotherapy Evidence Database and Cochrane Library. Randomized trials comparing FES versus CA or control group in the treatment of patients with CHF were included. Two reviewers independently extracted the data. Main analysis used a fixed-effects model. The search retrieved 794 articles, from which seven studies were included. Treatment with FES provided a smaller gain in peak VO2 compared with CA {-0.74 ml/kg per min [95% confidence interval (CI): -1.38 to -0.10]}. There was no difference in the muscle strength [-0.33 Nm (95% CI: -4.56 to 3.90)] and in the distance of the 6-min walk test [2.73 m (95% CI: -15.39 to 20.85)] on comparing FES with CA. An increase in peak VO2 of 2.78 ml/kg per min (95% CI: 1.44-4.13) was observed in FES versus the control group. Treatment with FES provides a similar gain in the distance of the 6-min walk test and in the muscle strength when compared with CA, but a small gain in the peak VO2. An increase in the peak VO2 can be obtained with FES as compared with the control group. Thus, FES may be an alternative in relation with CA for patients with CHF and with those who are unable to perform this kind of exercise.