Baroreflex activation therapy lowers blood pressure in patients with resistant hypertension: results from the double-blind, randomized, placebo-controlled rheos pivotal trial

J Am Coll Cardiol. 2011 Aug 9;58(7):765-73. doi: 10.1016/j.jacc.2011.06.008.


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.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Baroreflex / physiology*
  • Blood Pressure / physiology*
  • Carotid Sinus
  • Double-Blind Method
  • Electric Stimulation Therapy* / adverse effects
  • Electrodes, Implanted
  • Female
  • Humans
  • Hypertension / physiopathology
  • Hypertension / therapy*
  • Male
  • Middle Aged