The EVEREST II Trial: design and rationale for a randomized study of the evalve mitraclip system compared with mitral valve surgery for mitral regurgitation

Background: Mitral valve surgery is the standard of care for patients with symptomatic mitral regurgitation (MR) or asymptomatic MR with evidence of left ventricular dysfunction or dilation. Whether an endovascular approach to repair can offer comparable effectiveness with improved safety remains to be determined in randomized trials.

Study design: The EVEREST II Trial is a multicenter, randomized controlled trial to evaluate the benefits and risks of endovascular mitral valve repair using the MitraClip device compared with open mitral valve surgery (control) in patients with moderate or severe MR. Using a 2:1 randomization ratio, the trial is enrolling up to 186 MitraClip-treated subjects and 93 control subjects. Trial end points include a primary efficacy end point: the proportion of patients free from death, surgery for valve dysfunction, and with moderate-severe (3+) or severe (4+) MR at 12 months; the primary safety end point includes the proportion of patients with death, myocardial infarction, reoperation, nonelective cardiovascular surgery, stroke, renal failure, deep would infection, ventilation >48 hours, gastrointestinal complication, new permanent atrial fibrillation, septicemia, or transfusion of >or=2 U at 30 days or hospital discharge, whichever is longer.

Conclusions: This randomized controlled trial is designed to evaluate the performance of endovascular mitral repair in comparison to open mitral valve surgery in patients with significant MR.