Less invasive technique for repair of heart's mitral valve is better than surgery -- at least in the short term
A catheter-based procedure that uses a clothespin-like device threaded through the groin to repair a leaking mitral valve in the heart has far fewer immediate complications than open-chest surgery and provides a better quality of life, researchers reported Sunday at an Atlanta meeting of the American College of Cardiology. The new approach offers a therapeutic option for patients who are too weak to undergo conventional surgery or who have other risk factors that would endanger them in the conventional procedure.
The mitral valve connects the left atrium of the heart to the left ventricle. It is like swinging doors in a convenience store that open to allow blood to flow into the ventricle, then close to prevent it from coming back into the atrium. When the valve is leaky, it doesn't re-close properly, allowing blood to regurgitate. The result of this is an enlarged, overworked heart and fluid overload that can seriously impair a patient's quality of life and lead to disability and even death. "Many patients with significant mitral regurgitation are so fatigued that they are all but put on bed rest," said Dr. Ted Feldman of Northshore University Health System in Chicago, who led the study.
About 4-million Americans suffer from mitral-valve leakage, and another 250,000 are diagnosed each year, according to the Society for Cardiovascular Angiography and Interventions. The current treatment is a surgical intervention in which surgeons open the chest and stitch the center of the two mitral leaves together. During pumping, blood flows around the central stitches. The stitches allow the valve to close properly during the heart's relaxation. But only about one in five patients who could benefit from the surgery receive it because of the risks of the operation, the SCAI said. Those patients typically receive medical management of their symptoms with drugs, but that allows the valve to continue to deteriorate.
The new device, called a MitraClip, was developed by Evalve Inc., which is now a subsidiary of Abbott. It looks much like a clothespin. Fitted onto the end of a catheter, it is threaded through blood vessels to the heart, where it is inserted through a pinhole-sized opening. It clips onto the center of the leaves, acting just like surgically inserted stitches.
Feldman and his colleagues enrolled 279 patients with moderate-to-severe or severe mitral-valve regurgitation at 37 North American medical centers. Two-thirds received the MitraClip, and the rest underwent conventional surgery. During the first 30 days after the procedure, major complications occurred in 9.6% of those receiving the MitraClip, compared with 56% of those undergoing surgery. Two surgery patients died, two suffered major strokes, and four needed emergency heart surgery. None of those receiving the MitraClip had those problems, Feldman said. At the end of a year, valve problems were resolved in 72% of patients receiving the clip and in 88% of those undergoing surgery.
Surgery is better in the long term, Feldman said at a news conference, "but it's not so much better that patients, given the choice, want to undergo the open-heart procedure. ... Part of what makes this attractive is that, when the clip doesn't work, surgery remains an option."
The device is already approved in Europe, where it sells for about $27,000 -- plus the cost of the surgery. The company hopes to get marketing approval in the United States soon.
The study was funded by Evalve, and Feldman is a consultant to the company.
-- Thomas H. Maugh II