Renal sympathetic denervation for treatment of drug-resistant hypertension one-year results from the Symplicity HTN-2 randomized, controlled trial

Background: Renal sympathetic nerve activation contributes to the pathogenesis of hypertension. Symplicity HTN-2, a multicenter, randomized trial, demonstrated that catheter-based renal denervation produced significant blood pressure lowering in treatment-resistant patients at 6 months after the procedure compared with control, medication-only patients. Longer-term follow-up, including 6-month crossover results, is now presented. Methods and results: Eligible patients were on ≥3 antihypertensive drugs and had a baseline systolic blood pressure ≥160 mm Hg (≥150 mm Hg for type 2 diabetics). After the 6-month primary end point was met, renal denervation in control patients was permitted. One-year results on patients randomized to immediate renal denervation (n = 47) and 6-month postprocedure results for crossover patients are presented. At 12 months after the procedure, the mean fall in office systolic blood pressure in the initial renal denervation group (−28.1 mm Hg; 95% confidence interval, −35.4 to −20.7; p < 0.001) was similar to the 6-month fall (−31.7 mm Hg; 95% confidence interval, −38.3 to −25.0; p < 0.16 versus 6-month change). The mean systolic blood pressure of the crossover group 6 months after the procedure was significantly lowered (from 190.0 ± 19.6 to 166.3 ± 24.7 mm Hg; change, −23.7 ± 27.5; p < 0.001). In the crossover group, there was 1 renal artery dissection during guide catheter insertion, before denervation, corrected by renal artery stenting, and 1 hypotensive episode, which resolved with medication adjustment. Conclusions: Control patients who crossed over to renal denervation with the Symplicity system had a significant drop in blood pressure similar to that observed in patients receiving immediate denervation. Renal denervation provides safe and sustained reduction of blood pressure to 1 year. Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: http://www.clinicaltrials.gov. (Circulation. 2012;126:2976–2982.)