[CIT2011]Symplicity HTN-1 and HTN-2 Studies of Catheter-Based Treatment for Hypertension
In a presentation at the China Interventional Therapeutics (CIT) 2011 meeting on March 18, 2011, Prof. Horst Sievert, Director of the CardioVascular Center Frankfurt, Germany, presented the latest data from the Symplicity HTN-1 and HTN-2 clinical trials which evaluated renal denervation (RDN) treatment, a new minimally invasive catheter-based treatment for hypertension.
Presented originally at the November 2010 American Heart Association Scientific Sessions in Chicago, Ill., and simultaneously published in the Lancet, results from the Symplicity HTN-2 study showed that using a specially designed radio frequency (RF) ablation system (the Symplicity Catheter System) may safely and substantially reduce blood pressure in hypertensive patients for whom medical therapy is insufficient.
The Symplicity HTN-2 trial randomized 106 patients with uncontrolled hypertension at 24 investigational sites. After six months, patients undergoing RDN treatment experienced an average drop in blood pressure of 32/12 mmHg, compared with an increase in blood pressure of 1/0 mmHg in the control group of patients who were treated with medical therapy alone (p<0.0001). Moreover, Prof. Sievert previously has presented data from 153 patients from the non-randomized Symplicity HTN-1 study showing that the reduction in blood pressure appears to be sustained through 2 years.
“These results are extremely positive,” said Prof. Sievert. “If these findings are sustained during long-term follow-up, renal denervation will become one of the most important interventions in cardiovascular medicine.”
Both Symplicity HTN-1 and HTN-2 studies found that the therapy was safe with regards to the procedure and through longer term follow-up. Renal vascular safety was assessed by imaging treated arteries both acutely and chronically for over 6 months. No evidence of RF treatment-related vascular abnormalities or stenoses was reported. Kidney function was assessed with serial measures of serum creatinine and calculation of estimated glomerular filtration rate (GFR). The mean GFR in the study cohorts remained stable.
Despite utilization of multiple anti-hypertensive medications, blood pressure control remains elusive for many patients. Renal Denervation represents a promising new therapy for treatment-resistant hypertension.
The Symplicity Catheter System targets sympathetic nerves in the adventitia of each renal artery. This new catheter-based approach aims to reduce hyper-activation of the sympathetic nervous system, which is often the cause of chronic hypertension. The one-time procedure aims to permanently reduce blood pressure and may also allow patients to reduce or eliminate the need for lifelong antihypertensive medications.
The Symplicity Catheter System is produced by Medtronic Ardian and is available for sale in Europe and Australia.