Emory study uses radiofrequency energy to permanently lower blood pressure
Woodruff Health Sciences Center | Dec. 22, 2011
The Emory Heart & Vascular Center is one of approximately 60 institutions nationwide, and the first in Georgia, to study an innovative approach to lower high blood pressure without the use of medication.
The Phase III, randomized SYMPLICITY HTN-3 trial focuses on patients with treatment-resistant high blood pressure, also known as resistant hypertension, which occurs when a person’s blood pressure remains high despite taking at least three different medications to lower it. The study seeks to enroll 1,060 participants across the U.S.
The minimally invasive technique, called renal denervation, uses a tiny catheter device to silence pathologic nerve fiber signaling to the kidneys. When overactive, these nerves can make high blood pressure uncontrollable.
“Too much activity of the nervous system is a major contributor to high blood pressure. When these nerves turn the kidney on, it ramps up blood pressure through multiple processes,” says Emory Healthcare cardiologist Chandan Devireddy, MD, assistant professor of medicine, Emory University School of Medicine and principal investigator of the trial at Emory.
During the procedure, the catheter is advanced through a minimal puncture in the groin and threaded into the arteries of the kidney. Once there, the catheter delivers low-power radiofrequency (RF) energy that generates a tiny electric current to heat the nerves in the walls of the artery and deactivate the nerves to the kidneys. The technique, called ablation, is similar to one commonly used by doctors to stabilize irregular heartbeats.
According to Devireddy, doctors have known for decades that there was a link between blood pressure and the kidneys, which are responsible for regulating the body’s water and salt balance. In the past, surgeons tried to remove these nerves. Blood pressure results were excellent but the open surgery exposed patients to more risks than they were willing to take.
“This study is taking a new, non-invasive approach to deactivating these nerves from the inside of the kidney arteries using 21st century technical advances,” says Devireddy, the principal investigator of the Emory study site. “Even though we are focused on treating uncontrolled high blood pressure, what we learn could eventually help us develop breakthroughs in the treatment of all forms of elevated blood pressure and possibly other disease states as well. The effects shown so far have been outstanding.”
Related studies conducted in Europe and Australia have shown safe, significant and sustained reductions of blood pressure in subjects with uncontrolled hypertension. On average, blood pressure was reduced by more than 30 mmHg following denervation treatment.
Other Emory investigators working on this study include Janice Lea, MD, Kevin Kim, MD, Lou Martin, MD, Khusrow Niazi, MD, and Greg Robertson, MD.
For more information on the Emory trial, please call 404-778-5050.