Abstract 4048: Chronic Vagus Nerve Stimulation in Patients With Heart Failure: Potential Predictors of Success
Background: Congestive Heart Failure (CHF) is a progressive disease associated with autonomic imbalance with increased sympathetic and decreased parasympathetic activity. We investigated Chronic Vagus Nerve Stimulation (CVNS) as a new promising therapeutic option for patients with CHF. The goal of this study was to identify patients most likely to benefit from CVNS.
Methods: In a multicenter pilot study 32 patients with CHF in NYHA class II-IV (age 56±11 years, LVEF 22±8%) were implanted with the CardioFit CVNS System (BioControl Medical, Ltd., Israel) consisting of a nerve stimulator, a multipolar stimulation lead placed around the right cervical vagus and a right ventricular sensing lead. Optimization of CVNS occurred during a 3-week run-in period post-implant and patients were followed for 6 months. Responders were identified on the basis of a 6-component composite end-point including (parameter and thresholds) NYHA (±1 Class); MLwHF® (±12 points); 6-minWT (±38 meters); LVEF (±5%); ESV/EDV (±10ml/m2 BSA) and NT-ProBNP (±20%). End-point score (sum of scores divided by number of components) could range from -1 to +1; patients with a score ≥0.4 were defined as responders.
Results: During follow-up 3 patients died and 29 were evaluated at 6 months, showing overall significant improvements in NYHA class, MLwHF®, 6-minWT and LVEF. The average end-point score was 0.4±0.06. Responders and non responders are compared in the Table⇓.
Conclusion: Data from the CardioFit pilot study indicate that >50% of patients with advanced CHF respond favorably to CVNS. Patients with indices of reduced parasympathetic activity at baseline appear to have a greater clinical improvement. Larger clinical trials are needed to confirm these findings.