Randomized Clinical Trial Data Show Medtronic, Inc. Symplicity™ Renal Denervation System Continues to Demonstrate Significant Blood Pressure Reduction in All Treatment Groups
Published: Aug 27, 2012
“We continue to see significant and sustained improvement in blood pressure levels for patients who receive renal denervation with the Symplicity system, as these 18-month average blood pressure reductions are consistent with the 12-month follow-up data for both groups,” said Murray Esler, M.B.B.S., Ph.D., principal investigator of the Symplicity HTN-2 trial and associate director of the Baker IDI Heart and Diabetes Institute of Melbourne, Australia. “This is encouraging since patients with treatment-resistant hypertension are often taking more than three antihypertensive medications and still are unable to control their blood pressure, which can put them at risk for various cardiovascular events such as heart attack, stroke or heart failure.”
In this trial, 43 patients initially randomized to renal denervation with the Symplicity system had an average blood pressure reduction of -32/-12 mm Hg from baseline [p<0.01] at 18 months. Thirty-one control patients who received renal denervation following the six-month primary endpoint (crossover group) had an average blood pressure reduction of -28/-11 mm Hg [p<0.01] at 18 months. These 18-month average blood pressure reductions are maintained for both groups from 12-month follow-up (-28/-10 mm Hg [p<0.01] for the initial treatment group; -24/-10 mm Hg [p<0.01] for the crossover group).
The average number of medications for patients in this trial did not change from baseline to 18-months. At 18months, pulse pressure improved significantly for patients in this analysis following treatment with the Symplicity system (-20 mm Hg from baseline for the initial treatment group [p<0.01]; and -18 mm Hg from baseline for the crossover group [p<0.01]). Pulse pressure is the numeric difference between systolic and diastolic blood pressure and may have predictive value in terms of cardiovascular complications, especially in older patients. It may be important to evaluate changes in pulse pressure as well as systolic and diastolic blood pressure when assessing the efficacy of antihypertensive therapy. This analysis showed three new hospitalizations in the initial renal denervation group due to hypertensive events.
Renal denervation therapy is a minimally invasive, catheter-based procedure that modulates the output of nerves that lie within the renal artery wall and lead into and out of the kidneys. These nerves are part of the sympathetic nervous system, which affects the major organs that are responsible for regulating blood pressure: the brain, the heart, the kidneys and the blood vessels.
The Symplicity system’s catheter and proprietary generator and algorithms were carefully and specifically developed through years of clinical experience to enhance the safety and effectiveness of the renal denervation procedure. The Symplicity renal denervation system has been successfully used for five years to treat nearly 5,000 patients with treatment-resistant hypertension worldwide. The Symplicity renal denervation system is not approved by the U.S. Food and Drug Administration (FDA) for commercial distribution in the United States.
ABOUT THE SYMPLICTY HTN-2 TRIAL
The Symplicity HTN-2 trial is an international, multi-center, prospective, randomized, controlled study of the safety and effectiveness of renal denervation in patients with treatment-resistant hypertension. One hundred and six (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 six months following randomization.
ABOUT TREATMENT-RESISTANT HYPERTENSION
Treatment-resistant hypertension, defined as persistently high blood pressure despite three or more anti-hypertensive medications of different types including a diuretic, puts approximately 120 million people worldwide at risk of premature death from kidney disease and cardiovascular events such as stroke, heart attack and heart failure. Research suggests that nearly one third of treated hypertensive individuals are considered resistant to treatment.[i] Additionally, these patients have a three-fold increase in risk of cardiovascular events compared to individuals with controlled high blood pressure.[ii]
ABOUT THE SYMPLICITY™ RENAL DENERVATION SYSTEM
The Symplicity renal denervation system was launched commercially in April 2010 and is currently available in parts of Europe, Asia, Africa, Australia and the Americas. The Symplicity system is only available in the United States for investigational use.
The Symplicity renal denervation system consists of a flexible catheter and proprietary generator. In an endovascular procedure, similar to an angioplasty, the physician inserts the small, flexible Symplicity™ catheter into the femoral artery in the upper thigh and threads it into the renal artery. Once the catheter tip is in place within the renal artery, the Symplicity™ generator is activated to deliver a controlled, low-power radio-frequency (RF) energy routine according to a proprietary algorithm, or pattern, aiming to deactivate the surrounding renal nerves. This, in turn, reduces hyper-activation of the sympathetic nervous system, which is an established contributor to chronic hypertension. The procedure does not involve a permanent implant.
The FDA granted Medtronic approval for the protocol for SYMPLICITY HTN-3, the company’s U.S. clinical trial of the Symplicity renal denervation system for treatment resistant hypertension in August 2011. More information about HTN-3 can be found at www.symplifybptrial.com.
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Any forward-looking statements are subject to risks and uncertainties such as those described in Medtronic’s periodic reports on file with the Securities and Exchange Commission. Actual results may differ materially from anticipated results.