Medtronic has obtained an investigational device exemption from the US Food and Drug Administration (FDA) to initiate SYMPLICITY HTN-4 clinical trial using its Symplicity renal denervation system.

SYMPLICITY HTN-4 study has been designed to assess the safety and efficacy of the Symplicity renal denervation system in the US patients with moderate uncontrolled hypertension.

The clinical trial, which enrolled its first patient at Duke University Medical Center, will enroll up to 580 patients with systolic blood pressures greater than or equal to 140 and less than 160mm Hg.

SYMPLICITY HTN-4 is Medtronic’s second randomized, controlled renal denervation clinical trial in the US and builds upon the company’s pivotal US clinical trial SYMPLICITY HTN-3.

SYMPLICITY HTN-3 study is evaluating the use of Symplicity renal denervation system in the US patients with uncontrolled hypertension.

Similar to SYMPLICITY HTN-3, the study will be blinded and include a sham control and will enroll patients at approximately 100 sites.

SYMPLICITY HTN-4 will measure the efficacy based on the ability of subjects to either meet the goal of achieving a systolic blood pressure below 140mm Hg or to achieve a pre-specified reduction in 24 hour ambulatory blood pressure.

The study will assess the safety by evaluating major adverse events at one-month and renal artery stenosis at six months.

Symplicity minimally invasive system includes a flexible catheter and proprietary generator and it is available in more than 80 countries across the globe.

Medtronic Renal Denervation general manager and vice president Nina Goodheart noted SYMPLICITY HTN-4 builds upon the company’s rigorous clinical evaluation of the Symplicity renal denervation system designed to carefully and progressively develop the clinical evidence platform for the treatment of hypertension.

"We’re excited to initiate this study, even while patient follow-up continues in our pivotal U.S. clinical trial for patients with uncontrolled hypertension who have systolic blood pressure at or above 160. The SYMPLICITY HTN-4 trial will allow us to potentially extend the benefits of renal denervation to patients with more moderate uncontrolled hypertension in the United States," Goodheart added.

The system obtained CE Mark approval in 2008 and is currently available only for investigational use in the US.