3-Year Data From Medtronic's SYMPLICITY HTN-2 Trial Presented

October 30, 2013—Medtronic, Inc. (Minneapolis, MN) announced the presentation of 3-year data from the SYMPLICITY HTN-2 at the TCT 2013: Transcatheter Cardiovascular Therapeutics conference in San Francisco, California. SYMPLICITY HTN-2, a randomized, controlled clinical trial of renal denervation in patients with uncontrolled hypertension. These data demonstrate results consistent with data reported previously at 6, 12, and 24 months of follow-up.

According to Medtronic, the data show an average blood pressure reduction of -33/-14 mm Hg [P < .01] from baseline and an overall response rate (systolic blood pressure drop ≥ 10 mm Hg) of 85% for patients initially randomized to treatment with the Symplicity system and available for 36-month evaluation (n = 40). Despite a mean systolic blood pressure of 183.5 ± 19.5 mm Hg before denervation, 50% of these patients achieved the goal of systolic blood pressure of < 140 mm Hg. The safety profile of renal denervation with the Symplicity system was also maintained at 3 years, with no newly reported device- or procedure-related serious adverse events. None of the patients treated with the Symplicity system followed through 3 years required renal artery stenting.

Medtronic noted that it SYMPLICITY HTN-2 patients were required to have severe, uncontrolled hypertension with a systolic blood pressure ≥ 160 mm Hg despite the use of three or more antihypertensive medications, including a diuretic. All patients were maintained on their usual antihypertensive medications and were randomly allocated in a one-to-one ratio to undergo renal denervation or no additional treatment (control group).

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 after assessment of the trial's primary endpoint at 6 months after randomization. This crossover treatment group experienced significant and sustained blood pressure reduction at 30 months after renal denervation, with an average reduction of -33/-13 mm Hg [P < .01] from baseline (n = 30).

Robert J. Whitbourn, MD, Associate Professor and Director of the Cardiovascular Research Centre at St. Vincent's Hospital in Melbourne, Australia, presented the data at TCT during an oral abstract session on renal denervation and endovascular intervention.

“As the first and longest-term experience in a randomized, controlled setting, these data mark a significant milestone for the renal denervation clinical community, as well as the single-electrode Symplicity system,” said Dr. Whitbourn, MD, “These results continue to demonstrate the impact renal denervation can have on patients with uncontrolled hypertension, and these data are an important contribution to the growing body of evidence supporting renal denervation with the Symplicity system as a therapy option for this underserved population.”

Medtronic's Symplicity renal denervation system 
treats uncontrolled hypertension by disrupting the output of hyperactive sympathetic nerves within the renal artery wall, which is central to the body's ability to regulate blood pressure. The device consists of a flexible catheter and generator with algorithms developed to enhance the safety and effectiveness of the renal denervation procedure. The Symplicity system received European CE Mark approval in 2008. The Symplicity renal denervation system is available for investigational use only in the United States, advised the company.

In addition to SYMPLICITY HTN-2, the Symplicity clinical trial program includes SYMPLICITY HTN-1, SYMPLICITY HTN-3, Global SYMPLICITY Registry, SYMPLICITY-HF, Symplicity Spyral Catheter Feasibility Study, HTN-Japan, and SYMPLICITY HTN-India.