Durable Blood Pressure Reduction Shown in Patients Treated with Symplicity Catheter
September 28, 2009 – Data supporting the long-term safety and effectiveness of renal sympathetic denervation (RDN) using radio-frequency ablation in treating patients with chronic hypertension were presented Sept. 25 at the Transcatheter Cardiovascular Therapeutics (TCT) conference in San Francisco.
The Symplicity Catheter System manufactured by Ardian Inc. delivers radio frequency (RF) energy from within the renal artery to block conduction in the surrounding renal nerves, thereby counteracting chronic activation of the sympathetic nervous system. In addition to blood pressure reduction, this treatment has shown promising results for chronic kidney disease, heart failure and metabolic syndrome. The treatment is performed in the catheterization laboratory using routine interventional techniques similar to those used in renal stent procedures. The 40-minute treatment is minimally invasive and does not involve a permanent implant. The Symplicity Catheter System has received CE mark approval in Europe, but remains investigational in the United States.
The data were presented at a late-breaking trial session and showed that patients in the study maintained a clinically significant reduction in blood pressure at one-year following treatment. The results stemmed from the Symplicity I Trial, which was the first clinical study to evaluate a catheter-based treatment for chronic hypertension. The study enrolled patients who had persistent elevated blood pressure despite taking an average of 4.7 medications. The multicenter study was conducted in Australia and Europe. Early results from this same trial were also recently reported in the Lancet (April 11, 2009) and The New England Journal of Medicine (Aug. 27, 2009).
The study's coprincipal investigator, professor Henry Krum, director, Center of Cardiovascular Research and Education in Therapeutics, Monash University, Melbourne, Australia, reported the 40-minute procedure safely produced a mean blood pressure reduction of -27/-17 mmHg at 12 months in the study cohort. These findings suggest that the single, catheter-based intervention may achieve a durable, clinically important reduction in blood pressure in this very difficult to treat population.
Both vascular and renal safety were also carefully assessed in the study and reported during the conference. Renal vascular safety was assessed by imaging treated arteries both acutely and chronically for up to nine months. No evidence of treatment-related abnormalities or stenoses was reported. Kidney function was assessed with serial measures of serum creatinine and calculation of glomerular filtration rate (GFR). The mean GFR in the study cohort remained stable at 12 months.
"I am very excited by these latest findings,” said professor Krum. “These data demonstrate that the reductions in blood pressure we observed at 12 months in our initial Lancet paper have been found to be durable amongst a much larger cohort of patients who have now completed the study."
Based on these results Ardian, Inc. has initiated the Symplicity HTN-2 trial, a prospective, multicenter randomized study comparing patients treated with renal denervation to those receiving rigorous medical therapy. The trial will enroll 110 patients with blood pressure over 160 mmHg, despite taking three or more antihypertensive medications. The primary endpoint for the trial will be blood pressure reduction at six months. Kidney function, vascular safety and additional efficacy measures will also be assessed. Patients will be followed for three years.
For more information: www.ardian.com