Typically patients suffering from mitral regurgitation (MR) have had but two options: surgery, or no treatment at all. One company is working to change that with its MitraClip system, currently being evaluated in the U.S. as a non-surgical repair option for MR.

Evalve (Menlo Park, California) said it has completed the enrollment for its Endovascular Valve Edge-to-Edge REpair STudy (EVEREST). The device received CE-mark approval earlier this year and the first series of patients were treated recently in Germany (Medical Device Daily, Sept. 26, 2008). According to Evalve, the MitraClip is the first commercially available treatment alternative that enables non-surgical repair for MR.

"Mitral valve surgery is one of the most traumatic surgeries that cardiothoracic surgeons perform, there is a high morbidity rate associated with it and the sicker the patients are there is a higher mortality risk with it as well," Ferolyn Powell, president/CEO of Evalve, told Medical Device Daily.

Powell said about half of the patients who undergo open mitral valve surgery end up needing to either go to a step-down nursing facility or receive at-home nursing care because they are unable to care for themselves after the surgery. Of the patients who have had percutaneous mitral valve repair with the MitraClip and did not require open surgery later, have all gone home without nursing care, she said.

"The MitraClip system itself is really a novel first-in-class technology and it's enabling interventional cardiologists to repair the mitral valve with a groin stick, basically, versus open heart surgery," Powell said.

MR is the abnormal leaking of blood through the mitral valve, from the left ventricle. It is the most common type of heart valve insufficiency in the U.S., affecting millions of people worldwide, Evalve says.

Physicians in the catheterization laboratory perform percutaneous mitral repair with the MitraClip device. The heart beats normally during the procedure, and therefore does not require a heart-lung bypass machine. In addition to improving blood flow through the heart, the procedure may also relieve symptoms such as fatigue and shortness of breath that often affect patients with significant MR.

After treatment, patients generally recover quickly, the company noted. The MitraClip device may improve quality of life and may help MR patients avoid or delay surgery, having preserved surgical options (valve repair or replacement) should surgery become necessary, Evalve said.

"That was one of the real important things we set out to ensure when we designed and developed the product is that this could be a first line of care for some patients in that if it didn't work, their other options, their surgical options, are preserved," Powell told MDD.

EVEREST is an FDA-approved Phase II randomized, controlled, multi-center clinical research study in the U.S. and Canada evaluating the safety and efficacy of the MitraClip in 279 patients with moderate-to-severe (3+) or severe (4+) MR, as compared to surgical repair or replacement. The study effectiveness endpoint requires an MR reduction to = 2+ at one year. The primary effectiveness endpoint is freedom from surgery for valve dysfunction, death, and moderate-to-severe or severe mitral regurgitation at one year. The primary safety endpoint is freedom from major adverse events at 30 days or hospital discharge whichever is longer.

"The completion of enrollment in the randomized trial is an important milestone for the field of cardiology," said Ted Feldman, MD, director of the cardiac catheterization lab at Evanston Northwestern Hospital (Evanston, Illinois) and co-principal investigator of the trial. "It is the first randomized trial of any percutaneous mitral repair device compared to mitral valve surgery, and also the first large prospective evaluation of current mitral valve surgery using an independent core laboratory."

Overall, EVEREST investigators have treated more than 350 patients with more than 450 MitraClip devices implanted. Clinical data continues to grow, the company noted, and a significant number of three-year follow up results are available as well as four-year data from a smaller group of patients.

"Randomized trials provide valuable insight into directing future studies to improve therapy and match new therapies to the appropriate patient," said Donald Glower, MD, professor of surgery at Duke Medical Center (Durham, North Carolina) and co-principal investigator of the EVEREST study. "This trial sets a high scientific standard for future percutaneous valve therapies. As a result, this trial will have a significant and long-lasting impact on patient care around the world."

Registry data from the initial non-randomized cohort of EVEREST patients continue to indicate MR reduction is maintained over time in the majority of patients, hospital stays are short, fewer complications occur compared to mitral valve surgery and surgical options are preserved if needed.

"This is an important achievement for Evalve on the path to meeting regulatory milestones with the FDA," Powell said. "We believe the MitraClip system has the potential to provide patients suffering with MR an important alternative to surgery that will allow them to avoid the associated risks and trauma."