Anterior versus posterior leaflet mitral valve repair: A propensity-matched analysis

Objective: Mitral valve repair is superior to replacement for degenerative disease, but long-term outcomes of anterior versus posterior leaflet repair remain poorly defined. We propensity matched anterior and posterior repairs to compare long-term outcomes. Methods: Patients undergoing first-time degenerative mitral repair between 1992 and 2018 were identified. Primary outcome was overall survival. Secondary outcomes were postprocedural residual mitral regurgitation and reoperation. From 1025 patients, 1:1 propensity score matching was performed, yielding 309 anterior (isolated anterior = 85, bileaflet = 224) and 309 isolated posterior repairs. Results: Age was 58 +/- 15 years, ejection fraction was 57% +/- 10%, and matched groups were well balanced. Anterior repairs had longer bypass (122 +/- 53 vs 109 +/- 43 minutes, P = .001) and crossclamp (94 +/- 44 vs 85 +/- 62 minutes, P = .033) times. Mean residual mitral regurgitation grade was 0.44 (95% confidence interval, 0.24-0.65) for anterior repair and 0.30 (95% confidence interval, 0.13-0.47) for posterior repair (P = .31). Overall, 92%(569/618) of matched patients had no residual mitral regurgitation, with no differences in mitral regurgitation grade between groups (P = .77). Survival did not differ between anterior (10 years: 72% +/- 7%; 15 years: 63% +/- 7%) and posterior (10 years: 74% +/- 7%; 15 years: 60% +/- 8%) groups (log-rank P = .93). Linearized incidence of reoperation was 0.62% per patient-year, including 0.74% for anterior and 0.48% for posterior repairs. Cumulative incidence of reoperation at 15 years was 7.5% after anterior repair and 4.9% after posterior repair (Gray's test P = .26). Conclusions: No long-term survival or reoperation difference was found between posterior and anterior repair. On the basis of these findings, surgeons at centers of excellence should aim for repair of both anterior and posterior leaflet pathology with the same decision-making threshold over valve replacement for degenerative mitral disease.