This article is more than 5 years old. Information may no longer be current.
Renal denervation trial stopped, but technology may show promise
Click Here to Manage Email Alerts
SAN DIEGO — A trial of a renal denervation technology in patients with resistant hypertension was stopped for futility because it was not going to be able to meet its primary endpoint, but it showed promise for improving 6-month outcomes, according to a presentation at TCT 2018.
Michael A. Weber, MD, FACP, FACC, FAHA, professor of medicine at SUNY Downstate College of Medicine and a Cardiology Today Editorial Board Member, presented 6-month results from the REDUCE HTN: REINFORCE study of the renal denervation system (Vessix, Boston Scientific) in patients with resistant hypertension — clinic systolic BP 150 mm Hg to 180 mm Hg and 24-hour ambulatory systolic BP 140 mm Hg to 170 mm Hg — who were not taking BP medications at baseline.
After enrollment, patients had a 4-week run-in period and then were randomly assigned on a 2:1 basis to the renal denervation procedure or a sham procedure.
The primary endpoint was difference in reduction of 24-hour ambulatory systolic BP at 8 weeks. Secondary endpoints included medication additions and 24-hour ambulatory systolic BP at 6 months. Follow-up was planned for 3 years.
The trial needed to enroll 93 patients to be adequately powered for the primary endpoint, but after 51 patients were enrolled, an interim analysis was conducted due to difficulties in enrollment, Weber said.
“According to the interim analysis’ predefined statistical decision rule and confirmation by the data monitoring committee, it was determined that the trial could not achieve the primary endpoint at 8 weeks,” Weber said during the presentation. “The trial continued to follow subjects per protocol for those enrolled.”
In all, 34 patients (mean age, 58 years; 53% men) received the renal denervation procedure and 17 patients (mean age, 58 years; 76% men) received the sham procedure.
At 6 months, only one prespecified safety event occurred, a hospitalization for hypertensive crisis in a patient from the renal denervation group, Weber said.
At 8 weeks, 18% of the renal denervation group and 12% of the sham group were on antihypertensive drugs, which climbed to 50% for the renal denervation group and 53% for the sham group at 6 months, he said.
The target of office systolic BP less than 140 mm Hg was identical between the groups at 8 weeks (24% each), but was reached by more patients in the renal denervation group at 6 months (52% vs. 12%; P = .0061), according to the researchers.
Between baseline and 6 months, the renal denervation group had numerically greater reductions in 24-hour ambulatory systolic BP (–16.7 mm Hg vs. –9.5 mm Hg; difference, –7.2; P = .0833) and 24-hour ambulatory diastolic BP (–9.1 mm Hg vs. –5.5 mm Hg; difference, –3.6; P = .1724) than the sham group, Weber said.
However, between baseline and 6 months, the renal denervation group had greater reductions in office systolic BP (–26.2 mm Hg vs. –14.8 mm Hg; difference, –11.4; P = .0059) and office diastolic BP (–12.9 mm Hg vs. –7.5 mm Hg; difference, –5.4; P = .037) than the sham group, he said.
Daytime systolic ambulatory BP was also reduced at 6 months in the renal denervation group vs. the sham group (P = .0213), he said.
“Late efficacy appearance might have been due to slow onset of effect on [sympathetic nervous system] afferent signals, or it might indicate that renal denervation is most effective in patients receiving BP medications,” Weber said during the presentation. “Although the study cohort was small, these preliminary data from a randomized sham-controlled trial suggest that the Vessix catheter is likely to be of clinical value in treating hypertension.” – by Erik Swain
Reference:
Weber MA, et al. Keynote Interventional Studies IX: Four Fascinating and Very Different Studies. Presented at: TCT Scientific Symposium; Sept. 21-25, 2018; San Diego.
Disclosure: The study was funded by Boston Scientific. Weber reports he consults for AbbVie, Ablative Solutions, Boston Scientific, Johnson & Johnson, Medtronic, Novartis and ReCor and receives research grants from Ablative Solutions, Astellas, Boehringer Ingelheim, Boston Scientific, Johnson & Johnson, Medtronic, Novartis and ReCor.