Late evolution of mitral commissurotomy in patients with low echocardiographic score.

OBJECTIVE The purpose of this study was to analyze the late results with open mitral commissurotomy in patients with low echocardiographic scores and to identify variables influencing these late results. METHODS We studied 50 patients who underwent open mitral commissurotomy due to rheumatic mitral stenosis at the Heart Institute University of São Paulo Medical School. Enrolled patients had a Wilkins echocardiographic score <or=9 and a mean mitral valve area (MVA) of 0.94+/-0.19 cm(2). Patients underwent clinical, electrocardiographic, and echocardiographic evaluations preoperatively, immediate postoperatively, at 6 months, at 12 months, and then annually for 11 years. RESULTS There was no hospital mortality. During 383.58 patient/years of follow-up, there were two late deaths, one related to valve disease. Actuarial survival was 94.3+/-4.0% at 11 years. The linearized reoperation rate was 1.3% patient/year, and the linearized thromboembolism rate was 0.8% patient/year. No patients developed endocarditis. The mean MVA was 2.50+/-0.44 cm(2) during the immediate postoperative period, decreasing to 1.74+/-0.4 cm(2) over 60 months (P<0.01). Although it was 1.40+/-0.24 cm(2) at 132 months, variations observed after 60 months were not significant. In regard to MVA, patients with higher echocardiographic scores had worse late results than patients with low scores (P=0.002). Neither the grade of subvalvular apparatus involvement nor MVAs during the preoperative and immediate postoperative periods significantly influenced the late evolution of MVAs. CONCLUSIONS Open mitral commissurotomy produces satisfactory results in patients with low echocardiographic scores.