Long-term chronic baroreflex activation: persistent efficacy in patients with heart failure and reduced ejection fraction.

AIMS: Baroreflex activation therapy (BAT) has recently been shown to reduce muscle sympathetic nerve activity and hospitalization rate while improving clinical variables through 6 months of therapy in patients with heart failure and reduced ejection fraction (HFrEF). The objective of the present study is to extend the information on this patient cohort over a long-term follow-up. METHODS AND RESULTS: Eleven patients were enrolled in the study and presented with optimized, stable medical therapy, New York Heart Association Class III HFrEF with left ventricular ejection fraction 40% or less, impaired functional capacity and no active cardiac resynchronization therapy. For the present report, muscle sympathetic nerve activity, baroreflex sensitivity data and hospitalization rate together with standard clinical data were collected at 12 and 21.5 ±â€Š4.2 months following BAT activation. Two patients died during long-term follow-up. The remaining nine patients maintained the improvements observed at 6 months, including reduced sympathetic activity and rates of hospitalization. CONCLUSION: BAT provides long-term chronic reductions in sympathetic activity and utilization of hospital resources in patients with HFrEF. General clinical presentation, quality of life and functional capacity are likewise improved and maintained. The temporal association of BAT with sympathetic drive diminution and improvement in objective clinical measures suggests a cause-and-effect relationship that will be verified in future randomized controlled trials of outcome.

Chronic baroreflex activation effects on sympathetic nerve traffic, baroreflex function, and cardiac haemodynamics in heart failure: a proof-of-concept study.

AIMS: Heart failure (HF) pathophysiology is believed to be mediated by autonomic dysfunction, including chronic sympathoexcitation and diminished baroreflex sensitivity, which correlate with mortality risk. Baroreflex activation therapy (BAT) is a device-based treatment providing chronic baroreflex activation through electrical stimulation of the carotid sinus. BAT chronically reduces sympathetic activity in resistant hypertension. The purpose of this investigation is to determine BAT effects in clinical HF. METHODS AND RESULTS: In a single-centre, open-label evaluation, patients with NYHA class III HF, EF <40%, optimized medical therapy, and ineligible for cardiac resynchronization received BAT for 6 months. Efficacy was assessed with serial measurement of muscle sympathetic nerve activity (MSNA) and clinical measures of quality of life and functional capacity. Eleven patients participated in the trial. MSNA was reduced over 6 months from 45.1 ± 7.7 to 31.3 ± 8.3 bursts/min and from 67.6 ± 12.7 to 45.1 ± 11.6 bursts/100 heartbeats, decreases of 31% and 33%, respectively (P < 0.01). Concomitant improvements occurred in baroreflex sensitivity, EF, NYHA class, quality of life and 6 min hall walk (6 MHW) distance (P ≤ 0.05 each). On an observational basis, hospitalization and emergency department visits for worsening HF were markedly reduced. One complication, perioperative anaemia requiring transfusion, occurred during the study. CONCLUSION: BAT was safe and provided chronic improvement in MSNA and clinical variables. Based on present understanding of HF pathophysiology, these results suggest that BAT may improve outcome in HF by modulating autonomic balance. Prospective, randomized trials to test the hypothesis are warranted.