Mitral Valve Clip Effective Alternative to Open-Chest Surgery

A novel mitral valve clip was proven to be as safe and effective as open-chest surgery in selected patients with mitral valve regurgitation, according to results of a late-breaking clinical trial presented at the 59th Annual Scientific Session of the American College of Cardiology. The MitraClip® System, an investigational device, improved left ventricular function, NY Heart Association functional class, and quality of life (QOL), reported investigators for the pivotal EVEREST II trial.

At 12 months, the clinical success rate was 72% in the MitraClip group versus 88% of patients who had surgery. Clinical success was defined as freedom from the combined outcome of death, mitral valve surgery or re-operation for mitral valve dysfunction, or mitral regurgitation >Grade 2 at 12 months. Major adverse events at 30 days occurred in 9.6% of the MitraClip group versus 57% of the surgery patients, a difference that was highly statistically significant (P<.0001).

“As clinicians, we have seen our patients transformed from highly symptomatic to highly functional with a cathether procedure — and without a long hospital stay or recovery period,” said lead investigator, Ted Feldman, MD, who is director of the Cardiac Catheterization Laboratory for North Shore University Health System in Evanston, IL. “We are excited about having our experience with individual patients [using this device] validated in a clinical trial.”

The MitraClip device is mounted on a catheter threaded through the femoral vein in the groin into the right atrium. The device acts like a clothespin to clip together and repair the flaps of a defective mitral valve. Standard treatment for mitral valve regurgitation is open-chest surgery, which is much more invasive and costly and has associated morbidity. Currently, of the more than 250,000 cases of significant mitral regurgitation diagnosed annually in the US, only 20% undergo mitral surgery.

The Endovascular Valve Edge-to-Edge Repair Study (EVEREST II) recruited 279 patients from 37 North American medical centers who had moderate-to-severe (Grade 3 ) or severe (Grade 4 ) mitral valve regurgitation. Patients were randomized in a 2:1 ratio to either the device group (n=184) or the surgical repair group (n=95, controls). Patients were evaluated by echocardiography and clinical exam at baseline, 30 days, six months, one year, 18 months, and then annually for five years.

Mean age of the study population was 66 years, and about two-thirds were male. Demographics were similar between the two groups, as were co-morbidities, with the exception of a greater percentage of congestive heart failure patients in the device group (90.8% versus 77.9%, respectively, P<.01).

For patients who have not been successfully treated with the MitraClip device, surgery remains an option, Feldman told listeners.

The study was funded by Evalve, a company recently acquired by Abbott.