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.