Late results of percutaneous mitral commissurotomy in a series of 1024 patients. Analysis of late clinical deterioration: frequency, anatomic findings, and predictive factors.

Abstract

The optimal use of percutaneous mitral commissurotomy (PMC) in a wide range of patients requires accurate evaluation of late results and identification of their predictors. Late results of PMC were assessed in 1024 patients whose mean age was 49+/-14 years. Echocardiography showed that 141 patients (14%) had pliable valves and mild subvalvular disease, 569 (55%) had extensive subvalvular disease, and 314 (31%) had calcified valves. A single balloon was used in 26 patients, a double balloon in 390, and the Inoue Balloon in 608. Good immediate results were defined as valve area >/=1.5 cm2 without regurgitation >2/4 (Sellers' grade) and were obtained in 912 patients. Median duration of follow-up was 49 months. The 10-year actuarial rate of good functional results (survival with no cardiovascular death and no need for surgery or repeat dilatation and in New York Heart Association [NYHA] class I or II) was 56+/-4% in the entire population. Follow-up echocardiography was available in 90% of the patients who experienced poor functional results after good immediate results and showed restenosis in 97% of these. In multivariate analysis, the predictors of poor functional results were old age (P=0.0008), unfavorable valve anatomy (P=0.003), high NYHA class (P<0.0001), atrial fibrillation (P<0.0001), low valve area after PMC (P=0.001), high gradient after PMC (P<0.0001), and grade 2 mitral regurgitation after PMC (P=0.04). PMC can be performed with good late results in a variety of patient subsets. Prediction of late events is multifactorial. Knowledge of these predictors can improve patient selection and follow-up.