Abstract
A controlled trial of renal denervation for resistant hypertension
Bhatt DL, Kandzari DE, O'Neill WW, et al.
N Eng J Med 2014; 370: 1393–1401.
Definitive treatments for resistant primary hypertension are limited with an estimated >50% of these patients non-compliant with medications. Renal denervation has been reported to cause significant blood pressure (BP) reduction at six months. The authors present the first double-blinded, randomized controlled trial (invasive sham procedure) showing no significant effect of renal denervation at six months in the primary (5 mmHg reduction in clinic BP), secondary (2 mmHg reduction in 24 h ambulatory BP), renal and safety endpoints. Of note, both groups had significant BP reduction (>10 mmHg, P < 0.001) demonstrating a powerful placebo effect from the sham procedure, thought to be due to improved compliance with diet and medication. Whether this placebo effect remains will be examined as the trial will continue for five years.
The study was well designed with intention-to-treat analysis, matched groups and appropriately powered. Limitations include short follow-up, no objective assessment of medication compliance or procedural success. However, this article should impress upon readers the importance of blinding and a proper control group with appropriate sham when reviewing results of trials involving devices or procedures.