Teresa Bumgartel didn’t see her little girl Abbey when she first learned to crawl. She also didn’t get a chance to see her take her first steps.

Marc Passman is the principal investigator at UAB for the international Rheos Trial.

“I was as low as you could be emotionally,” Bumgartel says. “I had no zest for life left in me.”

An international clinical trial at UAB is giving Bumgartel renewed hope. The Rheos® Hypertension Therapy System™ is a high-blood-pressure treatment that consists of an implantable device designed to electrically activate the body’s own natural blood-pressure-regulation system in order to treat drug-resistant hypertension.
The data collected from this study will be used by the Food & Drug Administration to evaluate whether the device should be made available for sale in the United States.

Bumgartel is one of approximately 260 people to have the device placed in their body in this trial. She was UAB’s first implant in January 2008. Bumgartel no longer has blood pressure readings above 250 any more, and she’s also not confined to the four walls of her bedroom.

“I’ve had blood-pressure readings as low as 120 over 80-something, which is very exciting,” she says. “I can finally be a part of what my children are doing. I can go to baseball games and watch now. Before I couldn’t even do that.”

Similar to pacemaker
Marc Passman, M.D., associate professor of surgery, is the principal investigator at UAB for the Rheos trial. He has implanted seven devices since the trial began this past year.

“The Rheos system is an interesting device because it works on blood pressure from a more central mechanism,” Passman says. “Many of the available medicines work on different pathways of blood-pressure control, but the stimulator device on the Rheos system stimulates the carotid baroreceptor directly, lowering blood pressure.”

A person can lower their blood pressure by rubbing their carotid artery just below the ear lobe on the right side of their neck, which sends small electrical impulses to the carotid sinus.

“It’s almost like rubbing your carotid with an electric stimulus that activates the carotid sinus,” Passman says. “It more or less fools the body into thinking it needs to lower the blood pressure. It’s essentially doing what the body is not doing on its own; it’s stimulating the carotid so the body will respond as it normally should when you have high blood pressure.”

The implanted device is the same size as a pacemaker and consists of a generator and two leads that are surgically implanted and wrapped around the carotid arteries where the baroreceptors are located.

A probe that goes on the chest wall over the power unit turns on the device externally. It is then activated through a remote computer where doctors can change the settings on the device to fit the patient’s needs.
“It’s like a pacemaker for the blood pressure,” Passman says.

Determining eligibility
Eligibility to participate in the study is based on a specific set of criteria. Candidates must: 
• Be ages 21 to 80
• Have a blood-pressure reading for which top number is 160 or above
• Have a blood-pressure reading for which the bottom number is 80 or above
• Be taking two or more drugs for high blood pressure
• Not have had a procedure or treatment such as radiation, endovascular stent placement or surgery to the carotid sinuses

The device is implanted in everyone participating in the clinical trial, but one-third of the participants do not have their device turned on for six months. Physicians do not know whether a recipient’s device is on or off during the first sixth months. Every patient has their device tested when they come in every month, and after six months every recipient’s device is turned on.

“Some of the early analysis suggests the Rheos device will have its intended effect,” Passman says, “but still there are questions that have to be answered.”

“We do know that all of the people who have the device see their blood pressure drop when they come in every month for their dose-response testing,” Passman says. “But the study has to determine other things like durability and tolerance. All of that should get sorted out in the research data.”

Bumgartel says the Rheos trial is giving her hope that her blood pressure will stabilize.

“There were no other options for me,” Bumgartel says. “I couldn’t function as a person. I’m grateful just to have this chance to see if we can get my blood pressure stabilized for good.”