The REDUCE HTN: REINFORCE: Randomized, Sham-Controlled Trial of Bipolar Radiofrequency Renal Denervation for the Treatment of Hypertension

Abstract

Objectives: The aim of this study was to investigate bipolar radiofrequency renal denervation in patients with hypertension not receiving medications at baseline.

Background: A blood pressure-reducing effect of renal denervation has been difficult to isolate in clinical investigations.

Methods: REDUCE HTN: REINFORCE (Renal Denervation Using the Vessix Renal Denervation System for the Treatment of Hypertension) was a randomized, sham-controlled multicenter trial. Patients with office systolic blood pressure (SBP) of 150 to 180 mm Hg and average 24-h ambulatory SBP of 135 to 170 mm Hg after medication washout underwent bipolar radiofrequency renal denervation or a sham procedure. The planned outcome was 8-week change in 24-h ambulatory SBP. Enrollment was terminated for apparent futility before a sufficient sample for powered efficacy comparisons was enrolled. Safety assessments included all-cause death, renal failure, severe hypotension or syncope, hypertensive crisis, and renal artery stenosis.

Results: Baseline 24-h blood pressure was 148.3 ± 10.9/85.7 ± 9.1 mm Hg for the denervation group (n = 34, mean age 58.5 ± 10.1 years, 47% women) and 149.1 ± 7.2/86.4 ± 9.8 mm Hg for the control group (n = 17, mean age 58.2 ± 9.8 years, 24% women). At 8 weeks, mean 24-h SBP reductions for the renal denervation and control groups were -5.3 mm Hg (95% confidence interval [CI]: -8.8 to -1.8 mm Hg) and -8.5 mm Hg (95% CI: -13.3 to -3.8 mm Hg), respectively (difference 3.3 mm Hg; 95% CI: -2.8 to 9.3 mm Hg; p = 0.30). Antihypertensive medications could then be added. By 6 months, decreases in SBP were greater for the denervation group, yielding between-group differences of -7.2 mm Hg (95% CI: -15.2 to 0.8 mm Hg; p = 0.08), -9.7 mm Hg (95% CI: -17.7 to -1.7 mm Hg; p = 0.02), and -11.4 mm Hg (95% CI: -19.2 to -3.7 mm Hg; p < 0.01) for 24-h, daytime ambulatory, and office measurements, respectively. Through 12 months, 1 patient (renal denervation group) had a hypertensive urgency requiring immediate management, and 1 experienced progression of renal artery stenosis.

Conclusions: Future studies of radiofrequency renal denervation must anticipate delayed treatment effects. (Renal Denervation Using the Vessix Renal Denervation System for the Treatment of Hypertension [REDUCE HTN: REINFORCE]; NCT02392351).

Keywords: antihypertensive agents; catheter ablation; hypertension; renal artery.