Acute Baroreceptor Activation Therapy Improves Hemodynamics in Heart Failure with Reduced Ejection Fraction: Early Results from a Chronic Pilot Investigation

Background: Prognosis in advanced heart failure with reduced ejection fraction (HFrEF) remains poor despite drug and device therapy innovation. Addressing the chronic hyperadrenergic state that predisposes to pump failure and arrhythmic death is central to improving outcome. Baroreflex Activation Therapy (BAT) has demonstrated therapeutic benefit in preserved-EF HF patients and HFrEF animal models. BAT confers benefit by reducing sympathetic and increasing parasympathetic nerve activity, thereby improving hemodynamics and circulatory efficiency. Methods: Patients enrolled in an open-label evaluation of BAT. Eligibility required NYHA Class III HF, left ventricular EF ≤40%, optimized medical management stable ≥4 weeks, 6-minute walk distance 150-450 m and no active treatment with cardiac resynchronization. Acute BAT hemodynamic effects were measured with a right heart catheter 1 day post-implant. Clinical variables and muscle sympathetic nerve activity (MSNA) will be measured at baseline, 3 and 6 months. Results: To date, 6 patients have been implanted over 6 months. Baseline characteristics: Age 65 ± 3.7, LVEF 30 ± 3.7% (mean ± SE), exhibiting elevated MSNA (42 ± 3 bursts/min), depressed renal function and poor quality of life. Patients were medicated according to treatment guidelines with β-blockers, ACE-inhibitors and diuretics. Hemodynamics (table) were recorded just after initiating BAT (Baseline) and 14 ± 2 min after activation (Sustained BAT).. Conclusion: In medically optimized HFrEF patients, acute BAT improves circulatory performance by significantly decreasing diastolic and mean pulmonary artery pressure as well as mean arterial pressure. Non-significant trends toward increased cardiac output and reduced heart rate and vascular resistance are also observed. Follow-up assessment with clinical variables and MSNA in an expanded cohort will provide insight into the magnitude of long-term improvement that can be expected from BAT in HFrEF.