Severity Score for Mitral Valve Repair in Active Infective Endocarditis

Objectives: Whether to perform mitral valve (MV) repair is often difficult during infective endocarditis (IE), especially in patients with extensive leaflet destruction. The aim of this study was to develop scoring system to predict feasibility of mitral valve (MV) repair and select appropriate surgical candidates for repair during active IE. Methods: Patients who underwent MV repair for active IE were retrospectively divided into two groups during average follow-up period of 81 months: if MV repair was performed without significant recurrence of MR, MV repair was defined as feasible (n=18), and MV repair was defined as non-feasible (n=7) when MV repair resulted in more than moderate MR postoperatively or required redo surgery. Extensiveness of the valvular destruction was assessed by valvular score (VS), and complexity of valve repair was assessed by technical score (TS). Severity score was defined as the sum of VS and TS. Patients with feasible and non-feasible MV repair were compared in severity score, and association between probability of feasible MV repair and severity score was evaluated. Results: Severity score was lower in feasible MV repair than nonfeasible MV repair (5.4±2.2 points vs. 10.7±1.8, respectively, Mann Whiteney U test: p < 0.001). The receiver operating characteristic curve revealed a cut-off value of 8 points as having the best balance of specificity and sensitivity for predicting feasible MV repair. Probability of feasible MV repair was 100% (14/14) in severity score ≤ 7 points, 67% (4/6) in severity score =8 points, and 0% (0/5) in severity score ≥ 9points. Conclusions: Feasibility of MV repair during active IE was associated not only with extensiveness of leaflet destruction but also with surgical technique which would be taken. Probability of feasible MV repair can be categorized into high, moderate, and low probability according to severity score as ≤ 7 points, 8 points and ≥ 9points.