Vagal stimulation for heart diseases: from animals to men. An example of translational cardiology.

A significant series of experimental and clinical studies have demonstrated the close association between reduced vagal reflexes (baroreflex sensitivity, BRS) and increased sudden and non-sudden cardiovascular mortality. Subsequently, evidence was provided that, also among chronic heart failure (HF) patients, depressed BRS is associated with a poorer outcome. At the same time, the encouraging results with experimental and clinical attempts to increase cardiac vagal activity led to a few experimental studies with vagal stimulation (VS) in different models for HF. We first performed a pilot study for VS in HF patients, and then in 2011 we reported the results of a small size multicentre clinical trial. The 6-month and 1-year results are encouraging for feasibility, safety and appear to have a favourable clinical effect. An ongoing large clinical trial will provide a definitive assessment of the efficacy and usefulness of chronic VS in HF patients.