BOSTON—A novel approach known as baroreflex activation therapy (BAT) led to a 30 percent improvement in New York Heart Association (NYHA) classification and an increase in quality of life among patients with heart failure and reduced ejection fraction who had failed previous therapies.
Lead researcher Michael Zile, MD, of the Medical University of South Carolina in Charleston, S.C., presented results of the phase II, randomized trial on May 15 during a late-breaking clinical trials session at Heart Rhythm 2015.
Zile said there was also a mean 60 to 70 meter increase six-minute hall walk and a mean 12-point increase in the quality of life score on the Minnesota Living with Heart Failure questionnaire.
“A decrease of 12 points is enormous,” Zile said. “For most pharmacologic therapies that are used in reduced ejection fraction heart failure, we have a decrease of five points. In the original CRT [cardiac resynchronization therapy] studies, it was a decrease of 10 points. This is clearly even larger than that, and that’s on top of pre-existing therapies.”
The researchers enrolled patients in the U.S., Canada, Germany, Italy and France and randomized them to receive BAT plus optimal medical and device therapy or optimal medical and device therapy alone. Patients had left ventricular ejection fraction less than 35 percent and a diminished six-minute hall walk of between 120 and 400 meters. They were also all Class III on the New York Heart Association functional classification system.
“These are patients who have symptoms with activities of daily living in which their activity level is markedly diminished and impacted by the presence of the heart failure,” Zile said.
At baseline, the mean number of medications used was 4.7 in patients who had undergone CRT and 4.6 in patients who had not undergone CRT. The most common medications were ACE inhibitors, ARBs, beta-blockers and diuretics. Of the patients, 95 received CRT and 45 did not receive CRT.
The benefit of BAT was larger in patients who had not undergone CRT compared with patients who had CRT, according to Zile.
“We don’t mean to suggest that CRT patients aren’t responsive,” he said. “We are just noting the fact that the no-CRT group seemed to have a more pronounced impact.”
BAT consisted of a 2 mm electrode surgically implanted on the carotid sinus and connected to a surgically implanted subcutaneous power unit. The device was implanted before patients left the hospital. They then returned at two- to six-week intervals to have the therapy increased in strength until they reach a maximum threshold for the therapy, according to Zile.
“This particular therapy is different from all other neuromodulatory therapies because it sends an afferent signal from the carotid sinus to the brain, in which there’s an integrated response from the brain back down to the body,” Zile said. “There’s an integrated effect of a reduction in sympathetic tone and an increase in parasympathetic tone, which means it targets all neuromodulatory abnormalities within this clinical syndrome of heart failure.”
Zile said the FDA recently approved the initiation of a large, prospective, randomized trial to confirm the results of this study. A trial enrolling 480 patients at 90 U.S. centers is set to begin in September and is scheduled to examine cardiovascular death and heart failure hospitalizations.
“This represents a therapy which can be applied to those patients in which you’ve exhausted all other therapies,” Zile said. “And it can be applied to those patients who are not candidates for CRT. It will fit into a unique position of therapy for this group of symptomatic patients.”