PREDICTORS OF EVENT-FREE SURVIVAL AFTER PERCUTANEOUS MITRAL COMMISSUROTOMY

Objective-To assess the long term functional result after percutaneous mitral commissurotomy and identify the predictors of event-free survi val following 10 years of experience. Design-Analysis of clinical, ech ocardiographic, and haemodynamic variables at baseline and after the p rocedure by univariate and multivariate analyses (Cox model). Setting- University hospital. Patients-532 consecutive patients receiving percu taneous mitral commissurotomy in the same institution. Results-The mea n (SD) follow up was 3.8 (4.0) years. Survival at 3, 5, and 7.5 years was 94%, 91%, and 83%, respectively; event-free survival was 84%, 74%, and 52%. Mitral valve anatomy was identified as the strongest indepen dent predictor of event-free survival. Age, cardiothoracic ratio, mean pulmonary artery pressure, and mean echocardiographic mitral gradient after commissurotomy were also found to be independent predictors of long term functional result. Event-free survival was 92%, 84%, and 70% at 3, 5, and 7.5 years in patients with favourable anatomy (echo scor e = 1), 86%, 73%, and 34% in patients with intermediate anatomy (echo score = 2), and 45%, 25%, and 16% in patients with unfavourable anatom y (echo score = 3). In patients aged less than or equal to 65 years, t he event-free survival rate was 80%, 70%, and 45% at 3, 5, and 7.5 yea rs upsilon 52%, 38%, and 17% in patients aged > 65 years. Conclusions- The anatomical form of the mitral valve and the patient's age were the most powerful predictors of event-free survival. Patients with interm ediate or unfavourable anatomy and those aged > 65 years have low 5 an d 7.5 year event-free survival rates. This must be taken into account when discussing the indications for percutaneous mitral commissurotomy ; immediate mitral valve replacement is a reasonable alternative to ba lloon mitral commissurotomy in patients with higher risk of functional deterioration after the procedure.