[2006] [P2102] Chronic vagal stimulation in patients with heart failure is feasible, safe and appears beneficial

G.M. De Ferrari¹, O. Ben Ezra², N. Ajmone-Marsan², M. Revera², M. Landolina², A. Odero³, L. Tavazzi³, P.J. Schwartz². ¹IRCCS Policlinico San Matteo, Dept. of Cardiology, Pavia, Italy; ²BioControl, Yehud, Israel; ³IRCCS Policlinico S. Matteo & Univ of Pavia, Dept. of Vascular Surgery, Pavia, Italy

Over the last 25 years we have provided experimental and clinical evidence that markers of impaired cardiac vagal activity are associated with increased risk for cardiac mortality and sudden death. Concomitantly, electrical vagal stimulation (VS) has been shown by us to prevent ventricular fibrillation in conscious dogs with a healed myocardial infarction and by others to control heart rate (HR) and improve ventricular function in dogs with heart failure. This background was the rationale for the recently started ongoing study aiming at assessing the feasibility, safety, and possible efficacy of chronic VS in heart failure patients (NYHA class III). Previously, VS has been used in man for intractable epilepsy and depression, thus aiming at a central effect, whereas our goal is to activate cardiac vagal efferent fibers.
We report the first human experience with CardioFit (BioControl Medical), a VS implantable system delivering heartbeat-synchronous pulses adjusted to the current HR by an imbedded microprocessor. A specifically designed tri-polar cuff electrode allows selective stimulation of mostly unmyelinated fibers.
We have initiated a study in NYHA class III patients implanted with the CardioFit system. VS is started 2-4 weeks after implant, slowly raising intensity until the desired effect is achieved. Six patients have been implanted; four and three have completed 3 and 6 month follow-up, respectively. The procedures have been successful and VS is well tolerated, with only mild side effects (cough and sensation of electrical stimulation, one case of transient voice alteration), that have all subsided within the first two weeks.
Acutely, VS reduced HR 5-10% without any side effect. After three months significant (p<0.01) reductions in left ventricular systolic (from 312 ± 102 ml to 260 ± 72 ml) and diastolic (from 246 ± 108 ml to 190 ± 82 ml) volumes were observed. At the 3 month follow-up all patients reported a subjective benefit.
Chronic VS in patients with advanced HF is feasible and appears to be safe. This technique may produce a HR effect and beneficial effects on LV volumes. Thus, this novel approach to the treatment of patients with HF appears promising.

Session Info: Poster session 3
Citation: Eur Heart J 2006, 27(Abstract Suppl), 330