Echocardiographic predictors of left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve after mitral valve reconstruction for myxomatous valve disease

OBJECTIVE To determine predictors of systolic anterior motion and left ventricular outflow tract obstruction (SAM/LVOTO) after mitral valve repair (MVRep) in patients with myxomatous mitral valve disease. BACKGROUND Mechanisms for the development of SAM/LVOTO after MVRep have been described; however, predictors of this complication have not been explored. We hypothesize that pre-MVRep transesophageal echocardiography (TEE) can predict postrepair SAM/LVOTO. METHODS Using TEE, the lengths of the coapted anterior (AL) and posterior (PL) leaflets and the distance from the coaptation point to the septum (C-Sept) were measured before and after MVRep in 33 patients, including 11 who developed SAM/LVOTO (Group 1) and 22 who did not (Group 2). RESULTS Group 1 patients had smaller AL/PL ratios (0.99 vs. 1.95, p < 0.0001) and C-Sept distances (2.53 vs. 3.01 cm, p = 0.012) prior to MVRep than those in Group 2. Resolution of SAM/LVOTO was associated with increases in AL/PL ratio and C-Sept distance. This reflects a more anterior position of the coaptation point in those who developed SAM/LVOTO. CONCLUSIONS These data suggest that TEE analysis of the mitral apparatus can identify patients likely to develop SAM/LVOTO after MVRep for myxomatous valve disease. The findings are consistent with the concept that SAM of mitral leaflets is due to anterior malposition of slack mitral leaflet portions into the LVOT. The position of the coaptation point of the mitral leaflets is dynamic and a potential target and end point for surgical designs to prevent SAM/LVOTO post MVRep.