CHICAGO — Vagus nerve stimulation (VNS) showed mixed outcomes for patients with heart failure, the INOVATE-HF study found. By 16 months, death or worsened heart failure was no less likely in patients implanted with a VNS device to increase parasympathetic tone and restore autonomic balance (30.3% versus 25.8% with no implantation, hazard ratio 1.14, 95% CI 0.86-1.53), according to Michael R. Gold, MD, PhD, of Medical University of South Carolina in Charleston, and colleagues. Nerve stimulation was in fact associated with a better 6-minute walk test (28.2-meter increase versus 4.6-meter decrease for control, P<0.01), however, as well as a increase in self-reported quality of life (Kansas City Cardiomyopathy Questionnaire score up by 11.2 points versus 6.9 points, P<0.01). Additionally, heart failure lessened in severity for implanted patients by 12 months (P<0.01). Outcomes appeared worse for women who received VNS, according to the raw data, but adjustment for potential confounders rendered the difference insignificant. “The long term treatment with chronic vagus nerve stimulation in heart failure patients appears to be safe, and it is consistent with the safety profile of vagus nerve stimulation for other indications,” Gold and colleagues concluded online in the Journal of the American College of Cardiology. However, despite improvements in quality of life and functional status, the technique did not improve “hard outcomes,” Gold told attendees at the American College of Cardiology 2016 Scientific Sessions. INOVATE-HF included 707 patients randomized to medical therapy with or without implantation of the BioControl CardioFit for nerve stimulation. Subjects had chronic heart failure with marked physical limitations, and an ejection fraction of 40% or less. “We cannot exclude a placebo effect,” Gold said during his presentation. He noted that his group deemed a sham study approach “inappropriate” for exposing a control group to the risks of implantation for several years without activating the device. What’s more, the author added, VNS has side effects that make it impossible to ensure patient blinding. In the eyes of many, VNS may still be beneficial in heart failure despite disappointing findings of late. But “the devil’s in the detail” of the technical aspects that should be tweaked, commented panelist Emerson C. Perin, MD, PhD, of Texas Heart Institute in Houston. Gold acknowledged it may have been “premature” to go into the pivotal study without first optimizing duty cycle or frequency rate when stimulating patients. “But at the time there was a lot of optimism,” he said. To parse out the right patients and procedural variables, “it’s time to go back to the drawing board and look at a simpler model or a different design,” he said. Disclosures BioControl Medical was the sponsor of INOVATE-HF. Gold reported consulting for BioControl Medical and receiving institutional research grants.