CVRx®, Inc.’s (Minneapolis, MN) carotid stimulator Rheos Baroreflex Hypertension System, a device reported on by us before, is now being investigated in a new efficacy multi-center 300-patient trial led by Columbia University Medical Center and NewYork-Presbyterian Hospital . Unlike what the press release from Columbia University states, the Rheos system has not been approved by the FDA for marketing, but rather has received an investigational IDE exemption to evaluate the safety and effectiveness of the system in treating hypertension.
From the press release by Columbia University Medical Center:
The Food and Drug Administration-approved system is implanted surgically, with minimal scarring, under the skin in the neck and electronically stimulates the receptors in the carotid sinus, the area located at the bifurcations of the carotid arteries that are responsible for regulating blood pressure.
Baroreceptors work like a thermostat that automatically turns on the air conditioning when the air temperature becomes too hot. By activating the baroreceptors and sending signals to the brain, the Rheos System causes the brain to perceive a rise in blood pressure. The brain then acts to reduce blood pressure by sending signals to the blood vessels, heart and kidneys, the major organ systems involved in the control of blood pressure.
“The system is designed to work by stimulating the baroreceptors in the carotid sinus to make it appear as if patients are more hypertensive than they really are, forcing the body to respond and lower blood pressure,” said Thomas Pickering, M.D., director of the CUMC Center for Behavioral Cardiovascular Health, and the national principal investigator of the trial. “For patients who have been unsuccessful at lowering extremely high blood pressures with the current pharmacological therapies, this device may be an invaluable option.”
The Rheos System includes two small stimulating devices, called “leads,” which are implanted, under general anesthesia, next to the carotid sinuses located on the right and left sides of the neck. It also includes a pulse generator that is about the size of a small cell phone, which is implanted in the chest (see picture, below). The generator delivers a pulse of energy between one and 7.5 volts to the leads, which conduct the energy to the carotid baroreceptors. The baroreceptors are then activated, generating nerve impulses that travel to the cardiovascular control centers in the brain, which then slow the heart rate and cause blood vessels to dilate, reducing the amount of pressure the heart must use to pump the blood, and reducing its workload.
In an earlier feasibility trial, 59 implants were done worldwide with no unanticipated adverse device effects, including device failures, arrhythmias, postural hypotension, or stenosis of the carotid artery.
One study subject is already seeing the difference in a big way. New Jersey resident Tom Pareso volunteered to have a Rheos installed when he reached the end of his rope with four different hypertension medications that left him exhausted and tired most of the day. The 47-year-old mosquito inspector said his job isn’t particularly stressful, but that his family has had a history of hypertension.
Press release: Surgical Intervention to Treat Severe Hypertension Beginning to Show Results in Clinical Trial …
RHEOS clinical trial page…
Flashbacks: Positive Results from Trial of Rheos Baroreflex Hypertension Therapy ; Novel Device for High Blood Pressure Implanted