Treating Mitral Regurgitation with Percutaneous Repair or Surgery

Progressive left ventricular dysfunction and congestive heart failure have been associated with severe mitral regurgitation. Left untreated, symptomatic patients have an annual rate of ≥5%. Symptoms can be managed medically, but this strategy does not alter disease progression. Guidelines recommend surgery for moderate-to-severe (grade 3+) or severe (grade 4+) mitral regurgitation in patients with symptoms or evidence of left ventricular dysfunction. One surgical approach to repair the mitral valve involves approximation of the mitral leaflets with suture to create a double orifice. This procedure is usually performed with an annuloplasty ring. Patients who have undergone this procedure have had successful results lasting as long as 12 years. An investigational procedure for mitral valve repair involves the percutaneous implantation of a clip that grasps and approximates the edges of the mitral leaflets at the origin of the regurgitant jet. Mitral repair with this device in 107 patients showed significant reduction in the severity of mitral regurgitation. Researchers recently designed the EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) to compare percutaneous mitral repair and mitral valve surgery to assess the efficacy and safety of percutaneous mitral valve repair compared with conventional repair or replacement. They reported results of the study in the New England Journal of Medicine [2011;364(15):1395-1406]. The researchers randomly assigned 279 patients with moderately severe or severe (grade 3+ or 4+) mitral regurgitation in a 2:1 ratio to undergo either percutaneous repair (n=184) or mitral valve surgery (n=95) of mitral regurgitation. The primary composite end point 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 the rate of major adverse events within 30 days, defined as the composite of death, myocardial infarction, reoperation for failed mitral valve surgery, nonelective cardiovascular surgery for adverse events, stroke, renal failure, deep wound infection, mechanical ventilation for >48 hours, gastrointestional complication requiring surgery, newonset permanent atrial fibrillation, septicemia, and transfusion of ≥2 units of blood. Of 258 treated patients (21 patients withdrew consent), 94% (n=234) complied with the protocol for the 12-month follow-up. Baseline characteristics were similar in the 2 groups, with the exception of a history of congestive heart failure (more common in the percutaneous repair group). There were 178 patients treated in the percutaneous repair group: of those, 23% (n=41) had grade 3+ or 4+ mitral regurgitation on assessment before hospital discharge and were referred for surgery. Of these 41 patients, 28 underwent subsequent mitral valve surgery (15 repair and 13 replacement procedures). In the surgery group, all 80 treated patients had mitral regurgitation of grade 2+ before hospital discharge. Among these patients, 14% (n=11) had mitral valve replacement and 86% (n=69) had repair, including 55% (n=38) who underwent leaflet resection and annuloplasty, 23% (n=16) who underwent annuloplasty alone, 20% (n=14) who underwent complex leaflet or chordal repair with annuloplasty, and 1% (n=1) who underwent an unspecified method of leaflet repair. The rates of the primary efficacy end point were 55% in the percutaneous repair group and 73% in the surgery group (P=.007). The rates of the components of the primary end point in the percutaneous group compared with the surgery group were: death, 6% in each group; surgery for mitral valve dysfunction, 20% versus 2%; and grade 3+ or 4+ mitral regurgitation, 21% versus 20%, respectively. Major adverse events occurred in 15% of patients in the percutaneous repair group and 48% of patients in the surgery group at 30 days (P<.001). Finally, compared with baseline, both groups had improved left ventricular size, New York Heart Association functional class, and quality-of-life measures. The researchers summarized their findings by noting that, “although percutaneous repair was less effective at reducing mitral regurgitation than conventional surgery, the procedure was associated with superior safety and similar improvements in clinical outcomes.”