Non-Surgical Treatment For Leaky Heart Valves Under Investigation At UC Davis Medical Center

Main Category: Cardiovascular / Cardiology
Article Date: 13 May 2006 - 0:00 PDT

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When Charis Bledsoe learned that her 77-year-old mother and housemate, Mattie Cooksey, was suffering from a severely leaking heart valve, it became evident why her mother had not been feeling well.

Over a period of about two months, Cooksey's breathing had been rapid and labored, and she tired quickly. Routine tasks such as taking out the garbage or picking up the mail became too taxing, and even walking from her bedroom to the kitchen weakened her. In addition, her complexion had turned to a grayish pallor, and her legs became swollen.

Currently, the only approved option for treating severely leaking heart valves is open-heart surgery with cardiopulmonary bypass. But UC Davis Medical Center is among 30 hospitals across North America that are participating in an FDA-approved clinical study of an experimental device for repairing a leaking mitral valve, (so-called mitral regurgitation), which does not require open-heart surgery. Instead, the experimental device and procedure use a catheter inserted into a vein at the groin, performed while the heart is still beating.

After having the procedure at UC Davis Medical Center, Cooksey returned home after three days, compared to the five-to-seven day hospital stay normally required after open-heart surgery. Two days later, Cooksey was "back to normal," said Bledsoe.

"She was back to fixing her own meals, and her breathing was great," Bledsoe said. "She moves around as fast as she was moving before, maybe faster. On a scale of one to 10, I'd say she's a 10."

Reginald Low and Jason Rogers are two of the UC Davis cardiologists performing this procedure, assisted by echocardiologist Bill Bommer. Cardiac surgeons Nilas Young and Royce Calhoun will perform the surgeries on patients randomly selected for the surgical comparison group.

"Patients are attracted to this procedure because it is a less invasive alternative to open-heart surgery," said Rogers. "In the future, we will likely be treating many more heart valve conditions with these catheter-based approaches.

The study that benefited Cooksey involves a minimally invasive procedure that uses a small clip to help properly close the leaflets of the mitral valve in patients with mitral regurgitation. The condition occurs when the leaflets of the heart's mitral valve do not close properly. The mitral valve is a one-way valve that separates the left atrium (a chamber in the heart that collects blood) from the left ventricle (a chamber in the heart that pumps blood out to the body).

For patients with mitral regurgitation, blood flows backward into the left atrium during the heartbeat, decreasing blood flow out to the body. When mitral regurgitation is severe, the left ventricle must pump harder to compensate. Continual backflow due to the condition places an extra burden on the heart. Eventually, the increased strain can cause other heart problems, such as ongoing damage to the heart muscle, inadequate circulation of blood in the body, stroke and, in some patients, sudden death.

So far, about 50 cases using the clip have been performed in the United States. UC Davis Medical Center is the only hospital in Northern California that has performed the procedure.

The Endovascular Valve Edge-to-Edge Repair Study (EVEREST) II is a randomized, multi-center study investigating the safety and efficacy of the MitraClip, produced by Evalve, a Menlo Park, Calif.-based company that designs, develops, manufactures and markets new devices to enable the percutaneous repair of cardiac valves. EVEREST II will compare the MitraClip process to the standard surgical mitral valve repair in patients with functional or degenerative mitral regurgitation.

During the procedure, a doctor inserts a catheter through the patient's skin in the groin area and guides it through the femoral vein into the affected area of the heart. A smaller delivery catheter that holds the MitraClip is then inserted through this tube to allow the clip to be guided into place and attached to the leaflets (the "swinging doors") of the mitral valve. After the clip is attached, it is deployed and the catheters are removed.

Mitral regurgitation is the most common type of heart valve insufficiency. An estimated four million people in the United States have significant mitral regurgitation, with an annual incidence of 250,000 newly diagnosed patients. About 50,000 of these patients under go open-heart surgery every year.

EVEREST II is a follow-up to an earlier feasibility study that enrolled 47 patients with moderately severe or severe mitral regurgitation who were experiencing symptoms or had a weakened left ventricle. Only 4 percent of those patients experienced a significant adverse event at 30 days. Ninety-three percent of the patients who had a significant reduction in mitral regurgitation at one month have maintained that improvement at one year. While all of the enrolled patients required surgery prior to the MitraClip procedure, 75 percent of those who received the clip remain free from surgery.

UC Davis Health System is an integrated, academic health system encompassing UC Davis School of Medicine, the 577-bed acute-care hospital and clinical services of UC Davis Medical Center, and the 800-member physician group known as UC Davis Medical Group.

UC Davis Health System
4900 Broadway, Suite 1200
Sacramento, CA 95820
USA
http://www.ucdmc.ucdavis.edu

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