Risk assessment and outcomes of systolic anterior motion in robotically assisted mitral valve repair

Systolic anterior motion (SAM) is a known complication of mitral valve repair characterized by displacement of the anterior leaflet to the left ventricle outflow tract (LVOT) during systole leading to mitral regurgitation (MR) and LVOT obstruction. However, the value of the previously reported risk factors in robotically assisted mitral valve repair (RAMVR) is unknown. We reviewed the peri-operative parameters of 197 consecutive isolated RAMVRs. Patients were retrospectively stratified into low-risk (0-4) and high-risk (5-9) groups based on the total numbers of previously reported risks factors. Operative details and outcomes were compared between groups and the predictive value of the risk factors was analyzed. The overall SAM rate after RAMVR was 3.0% (6/197) with no significant differences between low-risk and high-risk patients (2.4% vs. 4.1%, p = 0.79). Distance from coaptation to interventricular septum (C-sept distance) was the only significant univariable predictor. Both anterior mitral leaflet length and C-sept distance were shown to be discriminatory for SAM in receiver operating characteristic (ROC) analysis. Flexible annuloplasty bands were used more often in the high-risk group (98.6% vs. 91.1% p = 0.034). The peri-operative outcomes between low-risk and high-risk patients were similar. The incidence of SAM after RAMVR was relatively low. Anterior mitral leaflet length and C-sept measured on pre-operative echocardiography appear to be of some predictive value. Use of flexible bands was potentially a viable preventive surgical strategy. Most of the SAM incidences could be managed with medical management and did not persist post-operatively.