2011 ACC: Clipping the Valve Beneficial, but Surgery Better for Mitral Regurgitation

Study shows that percutaneous treatment of mitral regurgitation using MitraClip is no better than a surgical approach.

NEW ORLEANS — April 4, 2011 –A percutaneous treatment of mitral regurgitation using MitraClip was no better than a surgical approach; however there were some pluses for patients, including improvements in safety and fewer adverse events, researchers reported here today in a late-breaking news conference at the American College of Cardiology’s (ACC) 60th Annual Scientific Session and ACC.i2 Summit.

Ted Feldman, MD, director of the cardiac Catherization laboratory at NorthShore University Health System, Evanston, Ill, who reported the results of Everest II: Randomized Clinical Trial: Two Year Outcomes said, “The device compares favorably with conventional open heart surgery for select patients with mitral regurgitation. Both procedures reduced mitral regurgitation and produced meaningful clinical benefit, but the MitraClip® valve repair increased safety.”

The study was published simultaneously in the New England Journal of Medicine.

The procedure involves using a minimally invasive procedure that may make valve repair feasible for more people with MR. Feldman said the catheter mounted device is guided through an incision in the groin and into the femoral artery and on to the heart and “clamps the edges of the faulty valve together like a clothespin.” After getting the MitraClip®, “patients spend one or two nights in the hospital, versus five to seven days after open heart surgery, and they are back to full activity immediately,” he said. MR is a common and progressive disease affecting about 250,000 people

Researchers conducted a Phase II study of 279 patients in 37 centers who had grade 3 (moderate to severe) or 4 (severe) MR and were assigned in a 2-1 ratio to the Mitral Clip or standard surgery (184 clip; 96 surgery). Average age was 66 years and the majority were male. Most patients had concomitant diseases such as congestive heart failure CAD, previous MI.

The primary composite end point for efficacy was freedom from death, from surgery for mitral valve dysfunction and from grade 3+ or 4+ mitral regurgitation at 12 months. The primary safety end point was a composite of major events within 30 days.

After 12 months, the rates of primary endpoint and efficacy were 55% in the clip group and 73% in the surgery group ((p=0.007.) The respective rates of the components of the primary end point were death 6% in each group, surgery for mitral valve dysfunction 21% vs 20%.

Major adverse events occurred in 15% of patients in the clip group and 48% in the surgery group at 30 days (p, 0.001).

Researchers noted that there are still unanswered questions because without intervention, symptomatic patients have an annual death rate of 5% or more. Spencer King, MD, a past president of the ACC, addressed this issue when he moderated the press conference during which the study results were announced. “If you are a patient and you are eligible for either procedure, if you are told that there is a 22% chance you will have to get the surgery, you may still decide to do it,” he said.

Furthermore, he noted that the new study suggests that clip approach is likely to bring better outcomes as doctors gain experience and tease out factors that will separate patients who benefit most.

Feldman added that the populations for repair may grow, with older patients and sicker ones considering the clip, and that it may be important to look at subsets of patients. For example, a subset analysis found associations with patients older than 70, and functional mitral valve regurgitation compared to degenerative regurgitation.

The study was funded by Evalve, Inc. The author has no disclosures.