From the Editor — The Next Big Thing

Beth G. Sisk, Editor

It was set to be the “next big thing”. Designed to aid patients suffering from resistive hypertension who failed to respond to conventional medical therapy, the stakes were huge for catheter-based renal denervation to treat one of the most prevalent chronic conditions worldwide— persistently high blood pressure despite treatment with anti-hypertensives.

Fig. 1 – The Boston Scientific V2 renal denervation system study is now on hold.

The treatment works by applying radio frequency pulses to the renal arteries to deaden nerves in the kidneys that control blood pressure. According to the Cleveland Clinic, dozens of companies are developing similar technologies. However, although thousands of patients have been treated with these new devices in Europe, Asia, Africa, and Australia, no renal denervation system is yet approved and available in the US.

Medtronic’s Symplicity device received CE mark approval in 2010. But, in January, Medtronic made a stunning announcement that while its US trial for the Symplicity HTN-3 met its primary safety endpoint, it “failed to meet its primary efficacy endpoint,” a sustained reduction in systolic blood pressure at six months. This was its largest study to date, with more than 600 patients in multiple countries. Medtronic quickly halted three trials in the US, Japan, and India, and reported its results. Previous clinical trials with smaller enrollments had proved successful, and the company plans to continue selling the product in 85 countries.

Just two weeks after the Medtronic bombshell, Covidien declared plans to stop its OneShot Renal Denervation program, which had received a CE mark in February 2012. Covidien said this move was due to weak demand for the product.

Boston Scientific Corporation decided not to begin the start of its own renal denervation study in the US, until it has had time to analyze the Medtronic study failure and review its own approach with regulators. Boston Scientific had acquired its V2 system through the purchase of Vessix Vascular Inc., in November 2012.

In December, St. Jude Medical halted the trial of its EnligHTN IV trial, which was to be the first US clinical trial for its renal denervation system, after just a few months citing patient enrollment challenges. St. Jude’s device received the CE mark in August. The company reports that its second-generation device differs from Medtronics since it has multiple electrodes to perform neurostimulation, rather than a single electrode in the Symplicity. St. Jude says that it plans to continue pursuing the technology.

Renal denervation was big news last year. This year, all bets are off—for now. But is this the end for renal denervation? Only time will tell.