Medtronic’s GSR-DEFINE Study of Symplicity Spyral RDN System Enrolls First United States Patient

June 11, 2025—Medtronic announced the treatment of the first patient in the United States in the GSR-DEFINE clinical trial. The clinical study is documenting the safety and effectiveness of the company’s Symplicity Spyral renal denervation (RDN) system in a real-world setting.

The company stated that the first United States procedure was performed by Stan Thornton, MD, of Thomas Hospital, an affiliate of Infirmary Health in Fairhope, Alabama. Dr. Thornton is Principal Investigator for the United States GSR-DEFINE study.

According to the company, the GSR-DEFINE trial is an extension of the Global SYMPLICITY Registry, which is the largest study documenting the long-term safety and effectiveness of the Symplicity Spyral RDN system in a real-world setting in patients with uncontrolled hypertension.

Medtronic advised that GSR-DEFINE is a prospective, all-comer observational study conducted at 251 sites across 55 countries that will include 5,000 patients globally. More than 4,000 patients have already been enrolled outside of the United States.

At the EuroPCR 2025 conference in May, Medtronic reported that GSR showed 3-year declines in office systolic blood pressure of 16.3 mm Hg in 1,450 patients evaluated from outside the Unted States.

“The United States GSR-DEFINE study builds on the Global SYMPLICITY Registry with the goal of enhancing our understanding of how RDN can improve outcomes for United States patients with uncontrolled hypertension in everyday clinical practice,” commented Dr. Thornton in the company’s press release. “We are proud to begin enrolling patients in the trial and treating patients with the Symplicity blood pressure procedure—a promising solution for millions worldwide in need of alternative solutions.”

The Symplicity RDN system is approved for commercial use in more than 75 countries around the world, advised Medtronic.