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.

2 Responses to “MitraClip Compared with Surgery in EVEREST II”

  1. Update: At his ACC presentation Feldman also presented a second analysis that viewed the data as a comparison of treatment strategies in which mitral valve surgery following unsuccessful percutaneous repair was not considered an endpoint event. In this analysis, at 2 years the primary endpoint occurred in 62.7% of the MitraClip group versus 66.3% of the surgery group.

  2. David Powell , MD, FACC says:

    The study was not powered to look at these” treatment strategies”. The main author is enthusiastic, but may overstate his case. About half of the failed clips required valve replacement, clearly less desirable than repair. Including transfusions as an early complication is debatable, despite the observational data from other populations suggest a negative impact. The successful surgical repair rate in the degenerative group is not excellent. The comparable success/failure rate between the two arms in the functional MR group is more a reflection of surgical inadequacies…the” coapsis” technique holds promise re ventricular remodeling…but the company went bankrupt?

    Competing interests pertaining specifically to this post, comment, or both: