The US Food and Drug Administration (FDA) expanded the approved use of the CoreValve System to treat certain patients who have previously had a tissue aortic valve replacement and are in need of a second one.

This first-of-its-kind use is called aortic “valve-in-valve” replacement, and today’s approval expands the authorized use of the device to patients in need of this replacement who also are at high or extreme risk for complications associated with traditional open-heart surgery.

The heart’s four valves are tissue flaps that open and close with each heartbeat to ensure blood flows properly through the heart’s four chambers and to the body. The aortic valve is one of the four heart valves. Some patients whose own aortic valve failed to work properly in the past undergo open-heart surgery to replace the faulty valve with an artificial heart valve. Over time, artificial valves that are made of animal tissue wear out—becoming narrowed, leaky or both—and may need to be replaced again.

“The CoreValve System offers a less invasive treatment option for a significant number of patients with failed tissue aortic valves whose medical teams determine that the risks associated with repeat open-heart surgery are high or extremely high,” said William Maisel, M.D., deputy center director for science and chief scientist in the FDA’s Center for Devices and Radiological Health. “The approval is an important expansion of the authorized use of the transcatheter aortic valve replacement technology.”

The CoreValve is an artificial heart valve made of tissue obtained from the heart of a pig. For support, it is attached to a flexible, self-expanding metal frame made of nickel-titanium alloy. To implant the device, a doctor compresses the valve and puts it on the end of a delivery catheter (a tube-like device), and then inserts it via an artery in the leg or neck or via a small cut between the ribs. The catheter is pushed through the blood vessels until it reaches the failed tissue aortic valve. The CoreValve is then released from the end of the catheter and expands on its own so it anchors to the old failed valve. Once the device is in place, it opens and closes properly, restoring the aortic valve function.

To evaluate the safety and efficacy of the CoreValve System for aortic “valve-in-valve” replacement, the FDA reviewed clinical data collected from a clinical trial conducted in the U.S. of 143 participants. In the clinical trial, the estimated rate of survival without major stroke was 95.8 percent at 30 days and 89.3 percent at six months. This compares well to the corresponding rate reported previously for trial participants who received the same device to replace their own, native diseased or damaged aortic valve.

The major risks observed in the clinical trial included death, stroke, acute kidney injury, heart attack, bleeding, complications with the arteries used to insert the valve and the need for a permanent pacemaker. Bleeding and major complications with the arteries were the most frequently observed early adverse events. Medtronic, the manufacturer of the CoreValve System, will continue to follow study participants up to five years in a required post-market study to assess the long-term performance of the device.

The aortic “valve-in-valve” use of the CoreValve System should be limited to patients who need replacement of a failed tissue aortic valve but are at extreme or high risk of death or serious complications from traditional open-heart surgery. The decision regarding whether the product and procedure is appropriate for a particular patient should only be made after careful evaluation by the patient’s heart medical team, including a cardiologist and a cardiac surgeon. The CoreValve System should not be used in patients who have any infection; have a mechanical aortic heart valve; cannot tolerate blood thinning medicines; or have sensitivity to titanium or nickel or contrast media (the fluid used during the procedure to see internal structures).

The FDA previously approved the CoreValve System to treat patients whose own aortic valve has become severely narrowed as a result of calcium buildup around the heart valve (aortic stenosis) and who are considered to be at “extreme risk” or “high risk” for surgical aortic valve replacement.

Medtronic is based in in Minneapolis, Minnesota.