Two-Year Data From Symplicity HTN-2 Show Sustained Efficacy of Medtronic's Renal Denervation System

March 10, 2013—Medtronic, Inc. (Minneapolis, MN) announced that 24-month data from the Symplicity HTN-2 randomized clinical trial investigating renal denervation were presented at the 62nd annual scientific session of the American College of Cardiology in San Francisco, California. Professor Henry Krum, MD, presented the data. Prof. Krum is Chair of Medical Therapeutics, Professor of Medicine, and Director of the Monash Centre of Cardiovascular Research and Education in Therapeutics in Melbourne, Australia.

The Symplicity HTN-2 trial is an international, multicenter, prospective, randomized, controlled study of renal denervation in patients with treatment-resistant hypertension.

In the study, 106 patients were randomly allocated in a one-to-one ratio to undergo renal denervation with previous treatment or to maintain previous treatment alone (control group) at 24 participating centers. At baseline, the randomized treatment and control patients had similar high blood pressures: 178/97 mm Hg and 178/98 mm Hg, respectively, despite both receiving an average daily regimen of five antihypertensive medications. Patients in the control arm of the study were offered renal denervation following assessment of the trial's primary endpoint at 6 months after randomization.

According to Medtronic, the data show that patients initially randomized to treatment with the Symplicity renal denervation system (n = 40) sustained a significant drop in blood pressure (-29/-10 mm Hg from baseline [P < .01]) at 24 months. Additionally, 26 patients in the control group who crossed over and received renal denervation after assessment of the 6-month primary endpoint (crossover group) had an average blood pressure reduction of -35/-13 mm Hg [P < .01] at 24 months.

As summarized in the company's announcement, at 24 months, pulse pressure improved significantly for patients in this analysis following treatment with the Symplicity system (-18.5 mm Hg from baseline for the initial treatment group [P < .01] and -22.5 mm Hg from baseline for the crossover group [P < .01]).

In its press release, the company stated that these 24-month average blood pressure reductions demonstrate preservation of the blood pressure reduction for both groups reported previously at 6, 12, and 18-month follow-up. There were no device-related serious adverse events, no late vascular complications, and no significant decline in kidney function compared to preprocedure values reported out to 24 months postprocedure. 

In Medtronic's press release, Prof. Krum commented, “Patients with treatment-resistant hypertension are at a significant risk for cardiovascular events, including heart attack, stroke, and heart failure, making it critical that we find a new, effective, and safe approach to help them achieve sustained blood pressure control. These latest data add to the growing body of evidence demonstrating consistent blood pressure reduction with the Symplicity system and underscore its potential as an option for us to help our medication-refractory patients achieve better blood pressure control.”

Medtronic advised that in the United States, the Symplicity system is only available for investigational use. In August 2011, the US Food and Drug Administration granted Medtronic approval for Symplicity HTN-3, the company's United States clinical trial of the Symplicity renal denervation system for treatment-resistant hypertension. In April 2010, the Symplicity renal denervation system was launched commercially and is currently available in parts of Europe, Asia, Africa, Australia, and the Americas.