Medtronic has received conditional approval from the US Food and Drug Administration (FDA) to modify its CoreValve US Pivotal Clinical Trial.

The CoreValve System is designed to provide a minimally invasive, non-surgical treatment option for patients with symptomatic, severe aortic stenosis who are at high risk, or are ineligible, for open-heart surgery.

The Medtronic CoreValve US Trial includes two studies in different patient populations: one study of patients diagnosed as high risk for aortic valve surgery, and a second study of patients diagnosed as extreme risk.

In the revised design, the trial will assess the CoreValve System in extreme risk of patients in a single arm study with a primary endpoint of all-cause death or major stroke within 12 months and evaluates alternate implantation routes for delivering the transcatheter valve, such as the subclavian approach.

In the revised trial design, the patient group at high risk will be evaluated against a performance goal derived from contemporary studies and will be randomized one-to-one to either transcatheter aortic valve implantation (TAVI) with CoreValve or to surgical aortic valve replacement (SAVR).

Medtronic Structural Heart division vice president and general manager John Liddicoat said they have taken extensive input from the medical community, their investigators and the FDA, and are pleased to proceed with modifications to the trial design based on the discussions.