Electronic BP regulator implanted in first U.S. patient
An implantable battery-powered pulse generator device designed to reduce blood pressure by activating the nerves in the carotid sinus area is being tested in patients with hypertension.
The generator stimulates the nerves after the device is implanted under the collarbone of a patient. This stimulation can cause an appreciable drop in BP with minimal, if any, side effects, said John Bisognano, MD, PhD, associate professor of medicine in the cardiology unit at the University of Rochester Medical Center.
Bisognano, along with Karl Illig, MD, chief of vascular surgery at the University of Rochester Medical Center, were the first in the nation to implant the iPod-sized device into a 36-year-old recipient.
This procedure was part of a phase 2, trial, the RHEOS trial, which is funded by the device maker CVRx Inc. of Minneapolis. Illig is principal investigator of the trial, and Bisognano has been involved in the development of the technology.
The device has also been used in limited trials in Europe.
The RHEOS system is designed to be implanted for one month before it is turned on. After the initial start it should be frequently monitored. It is currently being offered in trial only to patients with the most refractory cases of hypertension.
As a phase 2 trial, we are obviously heavily focused on safety, and currently this is only being offered to the most refractory hypertensives, Illig told Cardiology Today. Right now, it is only being offered to patients whose BP exceeds 160 on three meds [including one diuretic] for two months, and thus it is open only to the real problem cases. Still, this may be up to 0.5 to 1 million patients based on the general perception of 60 million hypertensives in the United States, Illig said.
According to the American Heart Association, as many as 65 million Americans aged 6 and above have high blood pressure.
The eventual goals are to extend this to less severe cases as safety and efficacy data accumulate, Illig said.
The system is implanted and left alone other than testing for one month. Then for 12 months, the patient receives gradually increasing or decreasing electrical doses.
Side effects minimal
This device, if found effective, would offer a way to lower BP in patients who have not been able to control their blood pressure with medications and could conceivably reduce the need for pressure-lowering medications in patients with lesser degrees of hypertension, Illig said in a University of Rochester Medical Center press release.
Aside from standard periop risks, there have been no side effects. Bisognano said, This is a phase 2 trial, so we are constantly watchful for other potential complications, but we expect that the risk factors will be no different than implantation of a cardiac pacemaker.
While there is still potential to improve this treatment rate with known pharmaceuticals, is is time for the hypertension community to consider new options and technologies in the treatment of this rampant disease. Simply waiting for another new variant of a low -calorie or low-salt diet is not going to solve the problem, said Bisognano. by Craig Whitaker
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- Dr. Bisognano has no direct interest in the product mentioned in this article, nor is he a consultant for the company mentioned.