No heart failure benefit with vagus nerve stimulation
A trial assessing the implantable CardioFit® device designed to stimulate the parasympathetic nervous system in heart failure patients failed to meet its primary endpoints – reducing the rate of hospitalization due to heart failure or death by any cause.
"The results were not what we had hoped for, but despite this disappointment, we still feel this approach holds potential," said Dr. Michael Robert Gold of the Medical University of South Carolina in Charleston, South Carolina, US, who presented the results of the INOVATE-HF* trial at the 2016 meeting of the American Academy of Cardiology held recently in Chicago, Illinois, US.
The trial randomized 707 with New York Heart Association (NYHA) Class III heart failure 2:1 to receive the CardioFit® device (with gradually increasing stimulation) or standard therapy (control). The trial was not blinded, however, because implantation required surgery. [J Am Coll Cardiol 2016;doi;10.1016/j.jacc.2016.03.525]
After a mean 16 months of follow up, results were nearly identical, with an estimated annual control rate for the primary endpoints of 19.7 and 22.1 percent in the CardioFit® and control arms, respectively (hazard ratio, 1.14, 95 percent confidence interval, 0.86-1.53, p=1.37).
Some secondary endpoint outcomes – 6-minute walking distance (p<0.01), and quality of life (p=0.04) – improved more in the CardioFit® patients, 47 percent of whom also improved their NYHA score compared with 29 percent of control patients.
“Given the encouraging safety data and the tantalizing secondary endpoint data, our study suggests that there may be specific groups of patients who may benefit from this therapy while others may not,” Gold said. “It is clear from this study that this device will not benefit all patients with heart failure and a reduced ejection fraction.”
Gold is a steering committee member of BioControl Medical, who make the CardioFit® device and funded the trial.
*INOVATE-HF: Vagus Nerve Stimulation for the Treatment of Heart Failure