Impact of Subannular Reconstruction on the Late Reoccurrence of Functional Mitral Regurgitation after Mitral Valve Repair: A Meta-Analysis

Objective: The surgical treatment of functional mitral regurgitation (MR) remains a challenging problem due to the high reoccurrence rate of MR. Undersized ring annuloplasty only inadequately addresses the underlying ventricular disease, including papillary muscle displacement and subsequent leaflet tethering. Subannular reconstruction techniques have been developed to address these drawbacks of annuloplasty. The aim of our study was to evaluate the potential impact of adding such subannular techniques, on the late re-occurrence rate of functional MR.

Methods: A systematic literature search was conducted on PubMed, Embase and Google Scholar, using the terms “mitral valve annuloplasty” “functional mitral regurgitation,” “subannular mitral valve repair,” “posterior leaflet augmentation” and “papillary muscle relocation.” Meta-analysis was conducted using Comprehensive Meta-Analysis version 3 (Biostat, Englewood, New Jersey). Cumulative events were compared as odds ratios with a 95% confidence interval. The primary endpoint of the study was recurrence of mitral regurgitation >2 after mitral valve repair, as defined by follow up- echocardiography. Only studies reporting long-term echocardiographic outcome, defined as more than three years postoperatively, were considered.

Results: The keyword-based search revealed a total of 1728 potential publications. After removal of duplicate studies and exclusion of experimental and laboratory studies, abstract screening was conducted and yielded 70 relevant papers. Full-text review revealed 27 eligible manuscripts, while long-term echocardiographic data were available only in 11 (40,7%) of them. The cumulative number of 1247 patients included in these studies served as our study population. At time of 3–5 years follow up after mitral valve repair, our meta-analysis demonstrated a significantly lower late recurrence rate of mitral regurgitation >2 in those patients, who underwent annuloplasty in combination with subannular reconstruction (OR 0.33, 95% C.I. 0,23–0,5, p = 0,01).

Conclusion: The combination of subannular reconstruction and mitral valve annuloplasty significantly reduces the late re-occurrence of functional MR after mitral valve repair when compared with annuloplasty alone.