Medtronic PLC has moved two steps closer to widespread adoption of a new therapy that replaces a diseased aortic heart valve without the need to cut open the chest.

The Ireland-based device maker, which employs well over 8,000 people in the Twin Cities, got word from the Food and Drug Administration late Monday that the agency has expanded the number of patients eligible to get its CoreValve catheter-delivered ­aortic valve replacement therapy.

Hours earlier, the company announced it had received permission to sell the same device in Japan for frail patients who stand a high risk of dying from traditional open-chest procedures. Medtronic already had that approval in the U.S. and Europe, but Japan is widely regarded as having some of the toughest approval ­standards in the world.

Most patients who get transcatheter aortic valve replacement (TAVR) procedures are elderly and very sick with aortic stenosis. Two recent clinical trials reported median U.S. patients are in their 80s. But analysts and device companies are betting that the TAVR therapy will find a $4 billion global market by 2020 as doctors get better at doing the procedure and regulators like the FDA get comfortable to approve it for less-fragile patients.

Traditional aortic valve replacement avoids the need to “crack” the chest for open-heart surgery. Instead, Medtronic’s CoreValve and similar devices can be folded up and fed to the heart on the end of a long, skinny catheter inserted through an incision in the leg. Researchers are closely monitoring for higher rates of stroke and valve leakages compared to traditional procedures.

Boston Scientific and St. Jude Medical have ongoing clinical trials of their own TAVR devices. California’s Edwards Lifesciences had the first U.S. approval in 2011, but Medtronic quickly snapped up 40 percent of the market after two FDA approvals last year.

The FDA had only approved TAVR therapy for U.S. patients who are at high or extreme risk of dying from traditional surgery. But on Monday, the agency awarded Medtronic the industry’s first approval of TAVR for patients who have already had a surgically implanted valve and now need a new one.

Known as a “valve-in-valve” procedure, the therapy lets doctors deploy the CoreValve directly inside an existing surgically implanted valve that has worn out or narrowed from normal wear and tear. FDA chief device scientist Dr. William Maisel said in a news release that the approval would expand ­treatment options for a “significant” number of ­people.

A Medtronic spokesman said it was too early to tell how many, but he noted that about 200,000 people worldwide receive traditionally implanted aortic valves, which are expected to last about 15 years or more inside the body.

In Japan, the company announced Monday that regulators had approved ­CoreValve implants based on clinical studies that duplicated TAVR’s health-improvement findings in a Japanese population. Patients eligible to receive the devices there have severe ­aortic stenosis and can’t have traditional surgery.

Medtronic officials said they now look forward to setting reimbursement rates for the device with officials from the country’s Ministry of Health, Labor and Welfare.

Medtronic shares closed at $77.99 Tuesday, down 43 cents on the day.

 

Twitter:@_JoeCarlson