US-based medical technology company Medtronic has announced the randomization of the first patients in the SYMPLICITY HTN-4 clinical trial at Medical University of South Carolina, Piedmont Heart Institute and Duke University Medical Center.

SYMPLICITY HTN-4 is a randomized, controlled trial, evaluating the Symplicity renal denervation system in patients with systolic blood pressure greater than or equal to 140 and less than 160mm Hg, despite treatment with three or more anti-hypertensive medications of different classes).

SYMPLICITY HTN-4, which builds upon SYMPLICITY HTN-3, will be blinded and include a sham control and will enroll up to 580 patients at approximately 100 sites.

SYMPLICITY HTN-3 is a pivotal US clinical trial of the Symplicity renal denervation system for uncontrolled hypertension. The study has completed enrollment of 535 patients across nearly 90 US medical centers in May 2013 and the results are expected during the first half of 2014.

Medtronic Renal Denervation general manager and vice president Nina Goodheart said: "SYMPLICITY HTN-4 demonstrates Medtronic’s commitment to providing randomized safety and efficacy data for renal denervation in a wide variety of patients, as well as helping increase our understanding of the potential benefit of renal denervation for more patients with treatment resistant hypertension."

The Symplicity renal denervation system is a minimally invasive, device-based treatment option to those with sympathetic over-activation. The device features a flexible catheter and proprietary generator with which algorithms were specifically developed to enhance the safety and effectiveness of the renal denervation procedure.

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