The U.S. Food and Drug Administration is opening the door to having more patients with bicuspid aortic valves be treated with minimally invasive catheter valves though a new clinical study and a labeling change.

The market for these transcatheter aortic valve replacement (TAVR) devices is already growing at double-digit rates globally, and the FDA’s recent actions regarding Medtronic’s CoreValve Evolut system could expand the market for the devices further.

A typical aortic valve has three leaflets, which open and close to force oxygen-rich blood out of the heart’s main pumping chamber and into the body’s largest blood vessel. At birth, a bicuspid aortic valve only has two leaflets, and may become stiff over time or fail to stop blood from leaking back into the heart, according to the National Library of Medicine.

About 180,000 people in the U.S. and Europe are considered candidates for TAVR procedures each year, and about one in five people who opt to receive a traditional aortic valve replacement has a bicuspid aortic valve.

But in the past, patients with bicuspid aortic valves have not been seen as strong candidates for the new catheter-delivered TAVR valves because of questions over how the devices deploy in the valve space, how the leaflets move and potential leaks and aortic complications.

Medtronic on Tuesday announced a label change that was approved by the FDA last month allowing the company to remove a precaution on the CoreValve Evolut product label regarding the use of TAVR devices for bicuspid patients. The removal of the precaution only applies to cases where the patient is at high or intermediate risk of fatal complications from a traditional valve replacement.

“The labeling revision will enable additional training and education for procedural TAVR sizing and placement in bicuspid patients,” Medtronic spokesman Joey Lomicky said in an e-mail about the news.

Boston interventional cardiologist Dr. Jeffrey Popma said data from the private STS/ACC TVT Registry, which is run by two surgery associations to track real-world transcatheter valve outcomes, shows a “near-parity” between bicuspid and tricuspid patients when using the Evolut valve system, despite the old label precautions.

“Real-world data suggest that TAVR with the self-expanding Evolut can be a suitable treatment option for many patients with bicuspid aortic valve disease,” Popma is quoted as saying in the Medtronic announcement.

In the Tuesday announcement, Medtronic unveiled an unblinded study of its CoreValve Evolut system in about 150 lower-risk patients. The FDA still considers the use of the device in low-risk bicuspid patients to be “investigational.”

“The bicuspid study, in addition to new studies on TAVR efficiencies and leaflet mobility, will provide important insights as we look to further refine TAVR therapy,” Medtronic structural heart medical affairs vice president Pieter Kappetein said in the announcement.