Baroreflex Activation Therapy Lowers Blood Pressure in Patients With Resistant Hypertension Results From the Double-Blind, Randomized, Placebo-Controlled Rheos Pivotal Trial

Objectives We sought to determine the effect of baroreflex activation therapy (BAT) on systolic blood pressure (SBP) in patients with resistant hypertension. Background The Rheos Pivotal Trial evaluated BAT for resistant hypertension in a double-blind, randomized, prospective, multicenter, placebo-controlled Phase III clinical trial. Methods This was a double-blind randomized trial of 265 subjects with resistant hypertension implanted and subsequently randomized (2: 1) 1 month after implantation. Subjects received either BAT (Group A) for the first 6 months or delayed BAT initiation following the 6-month visit (Group B). The 5 coprimary endpoints were: 1) acute SBP responder rate at 6 months; 2) sustained responder rate at 12 months; 3) procedure safety; 4) BAT safety; and 5) device safety. Results The trial showed significant benefit for the endpoints of sustained efficacy, BAT safety, and device safety. However, it did not meet the endpoints for acute responders or procedural safety. A protocol-specified ancillary analysis showed 42% (Group A) versus 24% (Group B) achieving SBP <= 140 mm Hg at 6 months (p = 0.005), with both groups achieving over 50% at 12 months, at which point Group B had received 6 months of BAT. Conclusions A clinically meaningful measure, those achieving a SBP of <= 140 mm Hg, yielded a significant difference between the groups. The weight of the overall evidence suggests that over the long-term, BAT can safely reduce SBP in patients with resistant hypertension. Future clinical trials will address the limitations of this study and further define the therapeutic benefit of BAT. (J Am Coll Cardiol 2011;58:765-73) (C) 2011 by the American College of Cardiology Foundation