Abstract 16137: Chronic Baroreflex Activation Reduces Sympathetic Tone and Improves Clinical Outcomes in Reduced-Ejection Fraction Heart Failure
Introduction: Heart failure mortality rate rises with increasing levels of sympathetic tone. Hyperadrenergic state directly mediates HF symptoms through vaso-/veno-constriction and fluid retention. Baroreflex activation therapy (BAT) reduces plasma norepinephrine and mortality while improving cardiovascular function in animal models of HF.
Hypothesis: To determine if BAT, as administered by the Barostim neo system, improves clinical presentation and outcomes of patients with reduced-ejection fraction HF (HFrEF).
Methods: HFrEF patients with the following characteristics were eligible to enroll in an open-label feasibility study: NYHA Class III, LVEF ≤ 40%, optimized medical therapy stable ≥ 4 weeks, 6-minute walk distance 150-450 m and no active treatment with cardiac resynchronization. Therapeutic effect was measured by hospitalization rate and surrogate variables including muscle sympathetic nerve activity (MSNA), walk distance, NYHA Class and the Minnesota living with HF questionnaire.
Results: Eleven patients (10 Caucasian, 3 female) were implanted. MSNA, NYHA Class, quality of life, and hall walk distance contemporaneously improved (table). Medical therapy burden declined. Blood pressure, renal function and weight were stable. Of 9 patients who completed 6 months of follow-up, cardiovascular hospitalizations were reduced by 75% compared to the 6 months prior to implant (from 8 to 2), while average duration of hospitalization decreased 59% (from 9.75 to 4 days).
Conclusions: BAT reduces hospitalization and improves clinical presentation in HFrEF. Concomitant reduction of sympathetic tone suggests a causal association. Larger prospective trials should verify this relationship and examine the impact of BAT on other key outcomes. Randomized trials of BAT in HFrEF are ongoing in North America and Europe.
- © 2013 by American Heart Association, Inc.