Vagus Nerve Stimulation for Heart Failure?
Paving the way for future research in improving heart function by stimulating the vagus nerve, a preliminary study showed improvements in heart failure conditions when the nerve was stimulated in test subjects.
The findings of the study were presented at the ongoing ESC Congress in Barcelona on Monday, two days after another study based on Vagus Nerve Stimulation (VNS) reported disappointment. Monday's findings, part of Autonomic Neural Regulation Therapy to Enhance Myocardial Function in Heart Failure or ANTHEM-HF trial, showed there was no difference in left-sided or right-sided vagus nerve stimulation.
According to Medical Xpress, the study involved 60 heart-failure patients with reduced ejection fraction and who were on medical treatment. The patients received a Vagus Nerve Stimulation (VNS) implant on either left or right side. Electrical stimulation was delivered for six months with an amplitude 2 mA at frequency of 10 hz.
Medpage noted that the left ventricular ejection fraction increase by 4.8 %, which is clinically significant, from 32.4 % to 37.2 % in six months.
"We pooled the results of the left and right side vagus nerve stimulation because there were no major differences in outcomes based on which nerve is stimulated. We saw both improvements in objective measures of heart failure and in subjective measures," the study's principal investigator Inder Anand said.
Parallels were also drawn with Saturday's presentation of NECTAR - HF which reported no improvements in cardiac function with VNS stimulation.
Medpage quoted Mariell Jessup, MD, professor of medicine at the University of Pennsylvania in Philadelphia, who said there was some confusion given the differing results of the two trials, but added that there was hope for newer therapies to emerge.
"They (ANTHEM-HF) compared right sided vagus nerve stimulation to left sided stimulation and both were effective. This is in contrast to NECTAR-HF which showed absolutely no signal, but was done primarily on the right side," she said.
VNS is a tested treatment for epilepsy and depression.