LONDON – Radiofrequency renal neurectomy (RF RDN) showed clinically meaningful reductions in blood pressure (BP) at night and throughout the circadian rhythm after 24 months, according to a study designed to reduce cardiovascular risk in patients with uncontrolled hypertension.
Konstantinos Tsioufis, M.D., Ph.D., professor of cardiology at the National and Kapodistrian University of Athens, Greece, presented the results at the European Society of Cardiology (ESC) Congress 2024. They showed that 24 months after the intervention, nighttime (1-6 p.m.) and morning (7-9 p.m.) blood pressure decreased by 12.0 and 14.8 mm Hg, respectively.
“Although the number of antihypertensive medications remained unchanged, nocturnal blood pressure was further reduced at 24 months compared with the 12-month results,” he reported. “By reducing nocturnal hypertension, the cardiovascular system will also gain incremental benefit.”
“Renal neurectomy prioritizes the reduction of nocturnal blood pressure, especially early morning blood pressure, which we know is more harmful for cardiovascular events,” Tsioufis said.
At 24 months, daytime (9 a.m. to 9 p.m.) and in-office blood pressures were reduced by 13.8 and 19.3 mm Hg, respectively.
He added that the number of hypertension medications was similar at 12 and 24 months after the intervention, noting that, unlike blood pressure medications that do not control blood pressure within 24 hours, the RDN was consistently effective.
Data came from the SPYRAL HTN-OFF MED Pivotal (n = 182) and SPYRAL HTN-ON MED (n = 206) trials. Both trials included patients with 24-hour mean systolic blood pressure ≥ 140 to < 170 mm Hg using ambulatory blood pressure monitoring. The first group took no medications and the second group took one to three medications in the previous 3 months. Their mean body mass index was 31.3, their mean age was 54 years, and 96% of patients with refractory hypertension had nocturnal hypertension (>120/70 mm Hg).
RF RDN was performed using the latest generation Symplicity Spyral multi-electrode catheter, which passes through the femoral artery in the groin into the renal artery, from where radiofrequency energy is delivered to the renal nerve.
12-Month Results from the Global SYMPLICITY Registry
In the same session, Markus Schlaich, M.D., professor of medicine and nephrologist at the University of Western Australia’s Perth Royal Infirmary, presented 12-month results evaluating blood pressure and renal function in patients with uncontrolled hypertension and changes in renal function after RF RDN.
Using data from 3,332 patients in the observational GSR DEFINE trial, the researchers found significant reductions in systolic blood pressure 12 months after RF RDN while maintaining renal function. Systolic blood pressure improved in all three renal function groups (estimated glomerular filtration rate [eGFR], < 45, ≥ 45 to < 60, and ≥ 60 mL/min/1.73 m2) and there was no increase in antihypertensive medication use.
The 24-hour blood pressure changes in the three eGFR groups were -5.7, -7.1, and -8.5 mm Hg, respectively.
“We found that the intervention was effective in all groups, did not adversely affect renal function, but achieved significant and clinically meaningful reductions in blood pressure, whether measured by in-office or ambulatory blood pressure,” Schlaich reported. “This is very reassuring and suggests that this is a good approach for these difficult-to-manage patients.”
Co-moderator Dr. Anastasia S. Mihailidou, a scientist at the Royal North Shore Hospital, Collin Research Institute, and Macquarie University Senior Hospital in Sydney, Australia, commented on the study. “This is an exciting time for the advent of new treatment options for hypertension, a major risk factor for cardiovascular disease and death,” she told Medscape Medical News.
“High nocturnal systolic blood pressure is an independent risk factor for cardiovascular disease. rDN surgery significantly reduces blood pressure and remains effective for up to 2 years after surgery,” she said, commenting on the study presented by Tsioufis.
Referring to Schlaich’s findings, she added that the results are “very encouraging because these patients had poor control of their hypertension and died of cardiovascular disease. In addition, appropriately designed studies are needed to confirm these findings in this global registry, but nephron neurectomy is an option for the treatment of hypertension that persists despite guideline-recommended medication adjustments. Promising treatment options certainly exist for patients and physicians.”