Developing a Prediction Model for Persistent Systolic Anterior Motion After Mitral Valve Repair

Background: We hypothesized that the distance between the anterior leaflet tip and the interventricular septum is a novel predictor for systolic anterior motion (SAM) after mitral valve repair. Methods: In this case-control study, we included 139 patients who underwent mitral valve repair for degenerative mitral regurgitation between November 2014 and August 2022. We conducted multivariable logistic regression analysis to investigate the impact of the predictors associated with persistent SAM. A prediction model was developed and assessed for discrimination and calibration, and its clinical implications were evaluated by decision curve analysis. Results: The overall incidence of persistent SAM was 5.8% (8/139). The distance between the anterior leaflet tip and the interventricular septum exhibited the most significant association with persistent SAM. The prediction model constructed with this index combined with the body surface area yielded a concordance index of 0.934. The calibration curve displayed good visual alignment with the ideal 45-degree line. Decision curve analysis revealed that the net benefit offered by the model consistently outperformed that of the "all or none" intervention strategies. Conclusions: The distance between the anterior leaflet tip and the interventricular septum, in conjunction with the body surface area, can be used to establish a prediction model for persistent SAM.