Introduction .– Percutaneous balloon mitral valvulotomy (PBMV) in rheumatic mitral stenosis is effective. However, complications such as severe mitral regurgitation (MR) may occur. Therefore, it is justified to predict the occurrence of this complication.

Objectives .– This study was undertaken to evaluate the morphology of the mitral valve and the subvalvular apparatus as assessed by echocardiography and its role in predicting the occurrence of MR after PBMV with the Inoue balloon.

Methods .– Three hundred and thirty patients who underwent 356 PBMV were evaluated retrospectively. MR occurred in 22 procedures (6.1%). We have compared the 22 patients who developed MR to 128 patients without MR or with mild to moderate MR. The morphology of the mitral apparatus on the baseline echograms was assessed: valvular mobility, thickening and calcification, commissural morphology, subvalvular thickening and heterogeneity of lesions distribution. Both Wilkins and Padial scores were calculated.

Results .– Echocardiographic predictors of severe MR were grade 2 MR (odds ratio = 6), Wilkins score (9,8 ± 2,9 vs 8,1 ± 2,5; P = 0,004) with a cut-off point of 10 (odds-ratio = 3), Padial score (12 ± 1,6 vs 8,8 ± 1,5; P < 0,001) with a cut-off point of 10 (odds-ratio = 28), heterogeneity of lesions distribution in the anterior mitral leaflet (odds-ratio = 17), commissural calcification (odds-ratio = 14) and subvalvular thickening (odds-ratio = 7). However, valvular mobility, thickening and calcification were unable to predict severe MR. The mechanism of severe MR was valvular tear in the most thin zones as assessed on echocardiography.

Conclusion .– Commissural calcification rather than valve calcification and the heterogeneity of lesions distribution rather than their severity are strong predictors of severe MR following PBMV. The Padial score based on these criteria has supplanted the Wilkins score in predicting this complication.