A Meta-Analysis of Ring Annuloplasty Versus Combined Ring Annuloplasty and Subvalvular Repair for Moderate-to-Severe Functional Mitral Regurgitation

Abstract

Background A ring annuloplasty (Ring) for moderate-to-severe functional mitral regurgitation (MR) is associated with suboptimal outcomes, and adjunctive subvalvular repair techniques (Ring + Subvalvular) have been advocated to improve repair durability. However, the outcomes of this strategy are not clearly defined. Methods A systematic review was performed to identify studies that compared a Ring versus Ring + Subvalvular repair for the treatment of moderate-to-severe functional MR. A meta-analysis was conducted on clinical outcomes and echocardiographic measures of follow-up MR and left ventricular reverse remodeling. Risk ratio (RR) and mean difference (MD) were calculated by the Mantel-Haenszel and Inverse Variance methods under a fixed or random effects model, as appropriate. Results Seven non-randomized studies were identified, with a total of 531 patients (Ring = 301, Ring + Subvalvular = 230). At follow-up (range 30-47 months), a Ring + Subvalvular repair was associated with a lower mortality (RR = 0.59, 95%confidence interval [CI] 0.37-0.94, p = 0.03), greater freedom from moderate or greater MR (RR = 0.44, 95%CI 0.27-0.72, p = 0.001), and improved left ventricular end-diastolic diameter (MD = -3.49 mm, 95%CI -5.45 to -1.53, p = 0.0005) and New York Heart Association functional class (MD = -0.25, 95%CI -0.42 to -0.08, p = 0.004). A trend toward a reduced risk of reoperation for recurrent MR was noted with a combined Ring + Subvalvular repair (RR = 0.28, 95%CI 0.06-1.22, p = 0.09). Finally, a Ring + Subvalvular repair did not impact operative mortality or follow-up left ventricular ejection fraction. Conclusion A combined Ring + Subvalvular repair for moderate-to-severe functional MR can be safely performed, and may improve mid-term outcomes, as compared with Ring alone. doi: 10.1111/jocs.12662 (J Card Surg 2016;31:31-37)