Low-frequency electrical muscle stimulation for 8 weeks did not significantly improve 6-minute walk distance compared to sham placebo in patients with severe heart failure (p=0.13).
RCT (n=60)
Double blind (participants, outcome assessors)
remotely by computer
No
Does low-frequency electrical muscle stimulation improve 6 min walk distance and feasibility outcomes in patients with severe heart failure?
A feasibility trial of low-frequency electrical muscle stimulation in advanced heart failure showed it is tolerable but yielded no significant improvements in exercise capacity or quality of life.
p-value: p=0.13
OBJECTIVES: Low-frequency electrical muscle stimulation (LF-EMS) may have the potential to reduce breathlessness and increase exercise capacity in the chronic heart failure population who struggle to adhere to conventional exercise. The study's aim was to establish if a randomised controlled trial of LF-EMS was feasible. DESIGN AND SETTING: Double blind (participants, outcome assessors), randomised study in a secondary care outpatient cardiac rehabilitation programme. PARTICIPANTS: Patients with severe heart failure (New York Heart Association class III-IV) having left ventricular ejection fraction <40% documented by echocardiography were eligible. INTERVENTIONS: Participants were randomised (remotely by computer) to 8 weeks (5×60 mins per week) of either LF-EMS intervention (4 Hz, continuous, n=30) or sham placebo (skin level stimulation only, n=30) of the quadriceps and hamstrings muscles. Participants used the LF-EMS straps at home and were supervised weekly OUTCOME MEASURES: Recruitment, adherence and tolerability to the intervention were measured during the trial as well as physiological outcomes (primary outcome: 6 min walk, secondary outcomes: quadriceps strength, quality of life and physical activity). RESULTS: Sixty of 171 eligible participants (35.08%) were recruited to the trial. 12 (20%) of the 60 patients (4 LF-EMS and 8 sham) withdrew. Forty-one patients (68.3%), adhered to the protocol for at least 70% of the sessions. The physiological measures indicated no significant differences between groups in 6 min walk distance(p=0.13) and quality of life (p=0.55) although both outcomes improved more with LF-EMS. CONCLUSION: Patients with severe heart failure can be recruited to and tolerate LF-EMS studies. A larger randomised controlled trial (RCT) in the advanced heart failure population is technically feasible, although adherence to follow-up would be challenging. The preliminary improvements in exercise capacity and quality of life were minimal and this should be considered if planning a larger trial. TRIAL REGISTRATION NUMBER: ISRCTN16749049.
Ennis et al. (Tue,) conducted a rct in severe heart failure (n=60). Low-frequency electrical muscle stimulation (LF-EMS) vs. sham placebo (skin level stimulation only) was evaluated on 6 min walk distance (p=0.13). Low-frequency electrical muscle stimulation for 8 weeks did not significantly improve 6-minute walk distance compared to sham placebo in patients with severe heart failure (p=0.13).