Renal Denervation Controls Treatment-Resistant Hypertension

Lara C. Pullen, PhD

April 07, 2011

April 7, 2011 (Chicago, Illinois) — Short-term data indicate that catheter-based renal sympathetic denervation is a safe and effective method of controlling treatment-resistant hypertension.

Marc R. Sapoval, MD, PhD, professor of clinical radiology and chair of the Cardiovascular Radiology Department at Hôpital Européen Georges-Pompidou in Paris, France, added to the continuing and growing data and research on this technology when he presented the results of the Symplicity HTN-1 study here at the Society of Interventional Radiology 36th Annual Scientific Meeting.

Symplicity HTN-1 is the first human randomized controlled trial of renal denervation (RDN), Dr. Sapoval announced.

Symplicity HTN-1 examined the use of the Symplicity Catheter System (Ardian, Inc., Palo Alto, California) for RDN of the sympathetic nerve supply to the kidneys, and involved 106 adults with resistant essential hypertension. Half of the patients received oral medication and half were treated with RDN.

Dr. Sapoval reported that after 6 months, 39% of patients receiving RDN had reached target blood pressure and, overall, 50% of patients showed a measurable benefit from the intervention. Systolic blood pressure fell an average of 32 mm Hg and diastolic blood pressure fell an average of 12 mm Hg. The effects appear to last at least 2 years in the patients studied for the longest period of time.

Approximately 1 in every 4 American adults has hypertension. There are many causes of hypertension, including benign tumors in the adrenal glands, stenosis of the renal artery, and certain prescription drugs. The current study targets patients with treatment-resistant essential hypertension, but Dr. Sapoval told Medscape Medical News that RDN might be effective for patients with less severe hypertension, although he adds that it is too early to confirm this.

RDN targets the sympathorenal system, which is one of the key players in the development and perpetuation of hypertension, the French researcher noted. Endovascular RDN might also be a useful treatment for disease states such as heart failure, cardiorenal syndrome, and hepatorenal syndrome. Currently, however, RDN is still experimental and the technique should only be performed by interventional radiologists on screened patients in strictly controlled academic and/or research settings, he emphasized.

Dr. Sapoval explained to Medscape Medical News that "in the United States, [RDN] will need to have FDA [US Food and Drug Administration] clearance, and that will likely take 2 years. In Europe, patients are already treated [with RDN], provided that they have resistant essential hypertension."

He noted that the trial was funded by the manufacturer of the catheter and specific generator, and that more independent research is needed. This should be accomplished soon with the upcoming FDA trial that involves more than 100 American interventional radiology teams.

Ziv J. Haskal, MD, FSIR, FACR, FAHA, FCIRSE, vice chair and professor of radiology and surgery and chief of vascular and interventional radiology at the University of Maryland Medical Center, Baltimore, discussed the research with Medscape Medical News. "If this continues to hold up in the larger multicenter controlled trials, it could prove to be one of the most important advances in the management of hypertension in decades."

Dr. Haskal added that the larger numbers of patients in the planned trials will allow for subgroup analysis, as well as a better understanding of the duration of the effect.

Previous results from Symplicity were reported at the American Heart Association’s Scientific Sessions last fall.

Dr. Sapoval and Dr. Haskal have disclosed no relevant financial relationships.

Society of Interventional Radiology (SIR) 36th Annual Scientific Meeting: Abstract 31. Presented March 28, 2011.