Renal Denervation for Resistant Hypertension: Blinded or Unblinding Recent Trial?

Abstract

Renal artery sympathetic denervation, performed via a percutaneous catheter ablation procedure applying radiofrequency energy, has been developed to address renal sympathetic overactivity as a pivotal mechanism in the pathophysiology of hypertension.¹ In 2009, the first-in-man experience with this procedure was published.² Several studies followed, including the Symplicity HTN-1 trial (n=45), the randomized Symplicity HTN-2 trial (n=106) and the expanded open-label Symplicity-2 study (n=153).^3-6 However, all the initial evidence suffered from important limitations related to small cohort size, short follow-up and by and large incomplete data.¹ According with a review and meta-analysis of 12 studies, most of them being observational studies without a control group, renal denervation in a total population of 561 patients with resistant hypertension, resulted in a significant reduction in mean blood pressure at 6 months.⁷ In the controlled studies (2 randomized controlled trials, n=133; and 1 observational study with a control group, n=50), there was a reduction in mean systolic and diastolic blood pressure at 6 months of –28.9 mm Hg and –11.0 mm Hg, respectively, compared with the control groups (p < 0.0001). In the uncontrolled studies (n=396), there was a reduction in mean systolic and diastolic blood pressure at 6 months of –25.0 mm Hg and –10.0 mm Hg, respectively, compared with the pre-procedural values (p < 0.00001). One renal artery dissection and 4 femoral pseudoaneurysms were reported as procedural complications.⁷... (excerpt)