Feb. 28 (UPI) -- French and U.S.-based researchers said that a device that uses ultrasound to calm nerves in the kidneys also can assist in regulating high blood pressure.
The results of a new study released Tuesday in the journal JAMA Cardiology showed that the device routinely reduced daytime ambulatory blood pressure by an average of 8.5 points among middle-aged people with hypertension.
Researchers at Columbia University in New York and University of Paris tested the device used in outpatient procedures called ultrasound renal denervation. It has not yet been approved by the Food and Drug Administration for use outside of clinical trials.
"Many patients in our clinical practice are just like the patients in our study, with uncontrolled blood pressure in the 150s despite some efforts," Dr. Ajay Kirtane, professor of medicine at Columbia University Vagelos College of Physicians and Surgeons and co-leader of the study, said in a statement.
"Renal ultrasound could be offered to patients who are unable to get their blood pressure under control after trying lifestyle changes and drug therapy before these events occur," added Kirtane, who is also an interventional cardiologist and director of cardiac catheterization laboratories at New York-Presbyterian/Columbia University Irving Medical Center.
According to the Centers for Disease Control and Prevention, persistent high blood pressure has been linked to a higher risk for dementia and a loss of cognitive function. High blood pressure also is a leading cause of stroke, a condition that is on the rise among younger people.
Scientists believe that hypertension in middle age can be caused in part by overactive nerves in the kidneys, which trigger water and sodium retention and release hormones that can raise blood pressure.
Ultrasound therapy has proven effective in calming overactive nerves in the renal artery, disrupting signals that lead to hypertension. The therapy is delivered to the nerves by a thin catheter that is inserted into a vein in the leg or wrist and threaded to the kidney.
The treatment will be evaluated by the FDA in the coming months, the researchers said.
Kirtane said improvements in blood pressure were noticed as soon as one month after the procedure.
The study pulled together information from three randomized trials encompassing more than 500 middle-aged patients with varying degrees of hypertension and medication use.
It found that twice as many patients who received the ultrasound therapy reached their target daytime blood pressure compared to patients in the sham groups.