April 4th, 2011
MitraClip Compared with Surgery in EVEREST II
The final results of the highly anticipated EVEREST (Endovascular Valve Edge-to-Repair Study) II were presented by Ted Feldman at the ACC Scientific Sessions in New Orleans and published simultaneously in the New England Journal of Medicine. Some 279 patients with moderately severe or severe mitral regurgitation (MR) were randomized on a 2:1 basis to either percutaneous repair with the experimental MitraClip device or conventional surgery for repair or replacement of the valve.
At 1 year, compared with patients in the MitraClip group, patients in the surgery group were significantly more likely to be free of death, surgery for mitral-valve dysfunction, or grade 3+ or 4+ MR at 12 months (the primary efficacy endpoint of the trial): 55% in the MitraClip group versus 73% in the surgery group (p=0.007). Here are the rates for the individual components of the primary endpoint:
- Death: 6% in each group
- Surgery for mitral-valve dysfunction: 20% with the MitraClip versus 2% with conventional surgery
- Grade 3+ or 4+ MR: 21% versus 20%, respectively
Both groups had improvement in the severity of MR following treatment, but the improvement was significantly greater in the surgery group. At 30 days, the rate of major adverse events was 15% with the MitraClip versus 48% with surgery (p<0.001). About one-fourth of patients in the MitraClip group had significant MR prior to hospital discharge and were referred for surgery.
The authors summarize their results: “We found that although percutaneous treatment was effective at reducing mitral regurgitation, surgical treatment was more effective, as graded by an echocardiographic core laboratory. However, percutaneous treatment was associated with a reduction in the rate of major adverse events at 30 days, as compared with surgery, and with sustained clinical improvement, as measured by quality of life, heart failure status, and left ventricular function.”
In an accompanying editorial, Catherine Otto and Edward Verrier write that “ideally, any new procedure would also be at least equivalent to surgical valve repair in terms of safety, valve function, durability, and long-term outcomes.” The MitraClip, they write, “fulfills some, but not all, of these criteria.” They note that the introduction of new minimally invasive devices poses a challenge to the traditional model in which the cardiologist usually decides whether a patient should be referred for surgery. “This approach breaks down as more options for intervention become available,” they write. They propose, in response, a “patient-centered approach to decision making” that would require “a true consensus of experts” following a review of each case.
For more of our ACC.11 coverage of late-breaking clinical trials, interviews with the authors of the most important research, and blogs from our fellows on the most interesting presentations at the meeting, check out our Coverage Roundup.