June 21, 2012

New therapy for treatment-resistant hypertension tested

New therapy for treatment-resistant hypertension tested

Vanderbilt Heart & Vascular Institute is participating in a clinical trial to test a new therapy for treatment-resistant hypertension.

Treatment-resistant hypertension is blood pressure that remains high (greater than 140/90 mmHg) despite treatment with three or more antihypertensive medications.

This study will look at a non-pharmacological approach known as renal denervation, a minimally invasive, catheter-based procedure.

It uses a tiny device that is threaded into the renal arteries to deactivate the nerves to the kidneys. Once in place, the tip of the catheter delivers low-power, radio-frequency energy to modulate the surrounding sympathetic nerves. When overactive, those nerves can raise blood pressure and contribute to heart, kidney and blood vessel damage.

“Renal denervation and ongoing treatment with antihypertensive medications have the potential to help patients achieve their target blood pressure levels,” said Mark Robbins, M.D., assistant professor of Medicine and co-principal investigator of the trial with Jay Gainer, M.D., chief of the Vanderbilt Hypertension Center.

Treatment-resistant hypertension affects nearly 6 million Americans and 100 million people worldwide and is associated with increased cardiovascular risk, including stroke and heart attack, as well as heart failure and kidney disease.

The clinical trial, known as SYMPLICITY HTN-3, is a randomized, controlled trial designed to evaluate the safety and effectiveness of the Symplicity renal denervation system, made by Medtronic, and will enroll about 530 patients at more than 60 medical centers.

The Symplicity renal denervation system has been successfully used since 2007 to treat more than 2,000 patients worldwide and has been commercially available in Europe and Australia since 2010.

The system is not approved by the U.S. Food and Drug Administration (FDA) for commercial distribution in the United States.

“We’ve had multiple types of drugs around for the treatment of patients with refractory hypertension, but no significant improvement in care of these patients has been as effective as the results of initial Symplicity trials,” Robbins said. “What we’ve seen is a marked improvement in blood pressure management.”

“If the success of this procedure in the initial trials can be replicated in the United States, this therapy could be quite a breakthrough for a significant proportion of patients who chronically require four or more blood pressure medications to establish acceptable BP control,” Gainer said.

The trial is currently enrolling patients. Contact study coordinator Sean Johnson at sean.a.johnson@vander-bilt.edu for more information.