Open mitral valvotomy. Effect of preoperative factors on result.

On hundred fifty-four patients who underwent open mitral valvotomy in the years of 1968 to 1976 were reviewed 1 to 112 months (mean 48) postoperatively. There was one hospital death and there were 14 late deaths (nine cardiac), and 16 patients required reoperation during the follow-up period. Preoperative factors were examined to assess their association with an unsatisfactory postoperative course. End points included unsatisfactory symptomatic status, the need for reoperation, and postoperative death. Maori race and atrial fibrillation (AF) were associated with all three end points. Other preoperative factors associated with at least one unfavorable end point were female sex, unfavorable preoperative symptomatic status, the presence of mild associated mitral incompetence (MI), a previous operation, and the presence of calcification in the mitral valve. The degree of subvalvular fusion and the adequacy of valvotomy assessed at operation were also related to outcome. A binary regression program was developed to assist in the prediction of outcome from an assessment of preoperative factors. Preoperative embolism occurred in 31 patients and postoperative embolism in 13. Postoperative embolism occurred in 35% of patients with a preoperative embolic episode and AF. Open mitral valvotomy carries a low operative risk, but unfavorable preoperative factors militate against a satisfactory long-term result and protection from recurrent embolism is only partial.