USA: Ultrasound renal denervation (uRDN) reduces blood pressure compared with a sham procedure, a recent study has shown. The study appeared in JAMA Cardiology on February 28, 2023.
The device, which uses ultrasound to calm overactive nerves in the kidneys, consistently reduced daytime ambulatory blood pressure by an average of 8.5 points among middle-aged people with hypertension.
Doctors usually prescribe lifestyle changes, such as reducing salt intake or losing weight, and medications to lower blood pressure in patients with hypertension. Yet about one-third of hypertensive patients cannot control their blood pressure despite these interventions.

“Many patients in our clinical practice are just like the patients in our study, with uncontrolled blood pressure in the 150s despite some efforts,” says Ajay Kirtane, MD, professor of medicine at Columbia University Vagelos College of Physicians and Surgeons and co-leader of the study.
Leaving blood pressure uncontrolled for too long can lead to heart failure, strokes, heart attacks, and irreversible kidney damage.
“Renal ultrasound could be offered to patients who cannot control their blood pressure after trying lifestyle changes and drug therapy before these events occur,” says Kirtane, an interventional cardiologist and director of cardiac catheterization laboratories at NewYork-Presbyterian/Columbia University Irving Medical Center.
The study's results tested the device used in an outpatient ultrasound renal denervation procedure. The device is still investigational and has not yet been approved by the FDA for use outside clinical trials.
Kidney nerves and hypertension
Hypertension in middle age is thought to be partly caused by overactive nerves in the kidneys, which trigger water and sodium retention and release hormones that can raise blood pressure. (In older people, hypertension often occurs as blood vessels stiffen). Antihypertensive drugs work in different ways to lower blood pressure, by dilating blood vessels, removing excess fluid, or blocking hormones that raise blood pressure. But none of these medications target the renal nerves directly.
Ultrasound therapy calms overactive nerves in the renal artery, disrupting signals that lead to hypertension. The therapy is delivered to the nerves via a thin catheter that is inserted into a vein in the leg or wrist and threaded to the kidney.
Study results
The new study pooled data from three randomized trials encompassing more than 500 middle-aged patients with varying degrees of hypertension and medication use.
Twice as many patients who received the ultrasound therapy reached their target daytime blood pressure (less than 135/85 mmHg) compared to patients in the sham groups.
"The result was almost identical across the different study groups, which definitively shows that the device can lower blood pressure in a broad range of patients,” Kirtane says.
The procedure was well-tolerated, and most patients were discharged on the same day. According to Kirtane, improvements in blood pressure were seen as soon as one month after the procedure.
The FDA will evaluate the treatment in the coming months.
The bottom line for patients with resistant hypertension
The investigators expect the treatment could be an adjunct to medication therapy and lifestyle changes for patients with uncontrolled hypertension.
“Once the device is available, we envision recommending it to patients who have tried other therapies first. The hope is that by controlling blood pressure, we might be able to prevent kidney damage and other effects of uncontrolled blood pressure,” Kirtane adds.
Reference:
Kirtane AJ, Sharp ASP, Mahfoud F, et al. Patient-Level Pooled Analysis of Ultrasound Renal Denervation in the Sham-Controlled RADIANCE II, RADIANCE-HTN SOLO, and RADIANCE-HTN TRIO Trials. JAMA Cardiol. Published online February 28, 2023. doi:10.1001/jamacardio.2023.0338