Medtronic continues to build up clinical data for its kidney nerve ablation procedure for treating stubborn high blood pressure. A randomized clinical study has shown significant and sustained reductions after three years.
The medtech giant’s catheter-based Symplicity Spyral device is designed to burn out and disrupt the signals from overactive nerves lining the arteries that lead to the kidneys, which are believed to play a role in drug-resistant hypertension as the organs work to remove salt and excess water from the bloodstream.
A previous model of the Symplicity system hit a roadblock in 2014 when it missed its endpoints in a pivotal trial. After that, the Spyral device returned—featuring four spaced-out electrodes for more even ablation—and demonstrated in 2020 that it could help lower blood pressure readings after three months in patients not taking anti-hypertensive drugs.
Now—in a separate, sham-controlled clinical trial of patients with high blood pressure despite taking between one and three medications—38 participants who underwent the renal denervation procedure showed a drop of 18.7 mmHg in their systolic blood pressure after 36 months, according to average readings taken from a 24-hour wearable monitor.
The control group of 42 patients, meanwhile, only demonstrated an 8.6 mmHg reduction at three years, and that came after they were allowed to make changes to their medication regimen at the six-month mark of the long-term study.
In addition, while the number of different medications taken by patients in both groups of the study largely remained consistent, the researchers’ measure of relative medication burden—driven by the amount and sizes of a patient’s daily doses—also saw reductions at 36 months in the renal denervation group.
After three years, 83.3% of treated patients reported a systolic blood pressure of under 140 mmHg, compared to 43.8% in the sham control group, after posting average baseline measurements of above 150 mmHg at the start of the study.
The clinical trial’s results were presented at the annual meeting of the American College of Cardiology (ACC) and simultaneously published in The Lancet.
Previously, Medtronic had presented data collected from a real-world registry of more than 2,500 international patients showing drops in office-measured systolic blood pressure by 17 mmHg regardless of the number of medications they were taking. The Symplicity Spyral system has not yet been approved for use in the U.S.
Elsewhere in the renal denervation space, ReCor Medical and its ultrasound-powered Paradise catheter demonstrated at last year’s ACC meeting that it could also make a dent in drug-resistant hypertension.
That randomized, sham-controlled study examined 136 patients, all taking at least three but sometimes more than five different medications. After two months, treated patients saw a median reduction of 8 mmHg in systolic blood pressure.
However, later last year—after ReCor began its European commercial launch—a separate study in Japan and Korea failed to meet its clinical target. ReCor and its corporate parent, Tokyo-based Otsuka, ascribed the miss to inadequately controlled usage of anti-hypertensive drugs among the study participants. The companies said they plan to conduct another study in Japan of the Paradise system.