The Mitral Leaflet Separation Index for assessment of mitral stenosis during percutaneous mitral commissurotomy: validation of the index in the immediate post-PMC period.

The aim of this study was to determine the utility of the mitral leaflet separation index (MLSI), for determining the results of percutaneous mitral commissurotomy (PMC) in the acute setting, in the cardiac catheterization laboratory. Forty-eight patients undergoing PMC were studied and 96 examinations were performed. The overall correlation with the MLSI was 0.95. The mitral valve area (MVA) was determined by 2D echo planimetry (MVAPLM ) and 0.83 of the MVA was derived using Gorlin's formula (MVAGOR ). The MLSI was significantly different in patients with severe mitral stenosis (MS) (MVAPLM <1 cm(2) , MLSI of 0.70 mm) compared with those with mild MS (MVAPLM >1.5 cm(2) , MLSI of 0.92 mm). The MLSI is a simple and effective method for assessment of the MVA. An MLSI >0.92, immediately after PMC, had an excellent sensitivity and specificity for the prediction of an effective MVA of >1.5 cm(2) .