Immediate results of percutaneous mitral commissurotomy - A predictive model on a series of 1514 patients

Background The wide use of percutaneous mitral commissurotomy (PMC) underlines the need to identify the predictive factors of the results. Using a large series allowed us to develop a multivariate model that can be applied to improve patient selection. Methods and Results Between 1986 and 1995, PMC was undertaken in 1514 patients. Mean age was 45+/-15 years. Echocardiography showed that 245 patients (16%) had pliable valves and mild chordal thickening (group 1), 886 (59%) had extensive subvalvular disease (group 2), and 383 (25%) had calcified valves (group 3). PMC failed in 22 patients; it was performed with a single balloon in 30 patients, a double balloon in 586, and the Inoue balloon in 876. Good immediate results were defined as a valve area greater than or equal to 1.5 cm(2) with mitral regurgitation Sellers' grade less than or equal to 2 and were obtained in 1348 patients (899). A logistic model developed from the first 1088 cases identified the following predictors of immediate results: age (P=.004), echocardiographic group (P<.0001), valve area (P<.0001), and effective balloon dilating area (EBDA) (P=.03). Two interactions were significant: age at previous commissurotomy (P=.013) and EBDA by initial mitral regurgitation (P=.034). The type of balloon was of borderline significance (P=.09). The model was validated on an independent sample comprising the subsequent 426 procedures. For a threshold of probability of good results of .75, sensitivity was 92%, specificity 25%, and predictive accuracy 87%. Conclusions Prediction of the immediate results of PMC is multifactorial. The predictive model developed and validated can be contributive in decision making Cor individual patients.