Long-term results of open mitral valulotomy for mitral stenosis.

Between 1979 and 1990, 163 patients underwent open mitral valvulotomy for pure or predominant mitral stenosi at Siriraj Hospital. There were 114 females (69.94%) and 49 males (30.06%), ranging in age from 7 to 71 years (mean, 30.69 years). Pre-operatively, 13 patients (7.98%) were in New York Heart Association (NYHA) functional class II, 138 patients (84.66%) in functional class III and 12 patients (7.36%) in functional class IV. The follow-up period ranged from 14 days to 11.33 years (mean, 3.27 years). Operative mortality was low (0.61%). Improvement in NYHA classification was found in 98 percent of these patients. At 12 years, the overall cumulative proportion surviving was 74; 59 percent of the patients survived without re-operation. In the analysis of factors affecting long-term results, there was no significant difference in any of the variable; sex, age, cardiac rhythm, mobility of cusps and subvalvular changes. This study clearly demonstrates the advantages of open mitral valvulotomy, which resulted in safe, effective and excellent long-term results.