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Background: Experimentally, vagal stimulation (VS) is protective in chronic heart failure (HF). In man, VS is used in refractory epilepsy but has never been used in cardiovascular diseases. Increased sympathetic and reduced vagal activity predict increased mortality in HF. Aims: This pilot study assessed feasibility and safety and tested possible efficacy of chronic VS in HF patients. Methods: We studied 8 patients (mean age 54 years). CardioFit (BioControl Medical), a VS implantable system delivering pulses synchronous with heart beats through a multiple contact bipolar cuff electrode, was used. VS was started 2-4 weeks after implant, slowly raising intensity; patients were followed 1, 3 and 6 months thereafter. Results: All procedures were successful: as sole surgical side effect, one patient had transient hoarseness. VS was well tolerated, with only mild side effects (cough and sensation of electrical stimulation). There was a significant improvement in NYHA class, Minnesota quality of life® (from 52 ±14 to 31 ± 18, p b 0.001), left ventricular end-systolic volume (from 208 ± 71 to 190 ± 83 ml, p = 0.03), and a favourable trend toward reduction in enddiastolic volume. Conclusions: This novel approach to the treatment of patients with HF is feasible, and appears safe and tolerable. The preliminary efficacy results appear promising. These findings suggest the opportunity to proceed with a larger multicentre study.

Ambulatory blood pressure increases progressively with increasing altitude, remaining elevated after 3 weeks. An angiotensin receptor blockade maintains blood pressure-lowering efficacy at 3400 m but not at 5400 m.