Hypertension Device Ineffective in Pivotal Study
Radiofrequency energy deactivates renal nerves (January 9)
The U.S. pivotal trial of the Symplicity system (Medtronic, Inc.) for renal denervation in patients with treatment-resistant hypertension, SYMPLICITY HTN-3, has failed to meet its primary efficacy endpoint.
The trial met its primary safety endpoint, however, and a data safety monitoring board concluded that there were no safety concerns in the study.
SYMPLICITY HTN-3 was the first blinded, randomized, controlled trial designed to evaluate the safety and effectiveness of renal denervation with the investigational Symplicity renal denervation system in patients with treatment-resistant hypertension and systolic blood pressure higher than 160 mm Hg in the U.S. Follow-up for all patients randomized in the trial will continue out to 5 years.
The study enrolled 535 patients with treatment-resistant hypertension at 87 centers in the U.S. Patients receiving the investigational treatment were compared with a sham-control group that did not receive treatment, with all patients continuing to take their blood pressure medications. Those in the control group had the option to receive the investigational treatment after the 6-month assessment of the primary endpoint.
The Symplicity renal denervation system consists of a flexible catheter and a proprietary generator. In an endovascular procedure, similar to an angioplasty, the physician inserts a small, flexible catheter into the femoral artery in the upper thigh and threads it into both renal arteries in turn. Once the catheter tip is in place within the renal artery, the Symplicity generator is activated to deliver controlled, low-power radiofrequency energy aimed at deactivating the surrounding renal nerves. This, in turn, is intended to reduce hyper-activation of the sympathetic nervous system, which is an established contributor to chronic hypertension. The procedure does not involve a permanent implant.
Source: Medtronic Inc.; January 9, 2013.