INDEPENDENT PREDICTORS OF LONG-TERM RESULTS AFTER BALLOON PULMONARY VALVULOPLASTY

Background This study was performed to determine independent predictors of long-term outcome after percutaneous balloon dilation of congenital pulmonary valve stenosis. Smaller follow-up series of patients after balloon pulmonary valvuloplasty have shown inconsistent results regarding the independent relation between prognostic factors and longterm outcome, as many patient selection and technical factors are correlated. Methods and Results Follow-up data were obtained for 533 patients from 22 institutions at up to 8.7 years after an initial balloon pulmonary valvuloplasty. Patients were grouped based on defined long-term outcomes, and the independent effects of patient selection and technical factors were sought in multivariate statistical analyses. At follow-up, 23% of patients were noted to have an outcome judged to be suboptimal because of either a residual right ventricle to pulmonary artery peak systolic gradient of greater than or equal to 36 mm Hg or further treatment of pulmonary stenosis requiring repeat balloon pulmonary valvuloplasty or surgical therapy. Significant independent predictors of a suboptimal long-term outcome included an earlier study year of the initial valvuloplasty (adjusted odds ratio, 0.71 per consecutive year), a small valve hinge point diameter (0.81 per l-mm increase), and a higher, immediate residual gradient (1.32 per 10 mm Hg increase). A smaller ratio of balloon to valve hinge point diameter significantly predicted suboptimal outcomes for patients with valve morphologies classified as typical (0.52 per 0.1 increase in ratio) and complex (primarily postsurgical valvotomy, 0.43) but not for patients with dysplastic (0.95) or combined morphologies (dysplasia with commissural fusion, 1.01). Patient age, the presence of Noonan's syndrome or associated cardiac lesions, pre-balloon valvuloplasty hemodynamic parameters, and the use of a simultaneous double-balloon technique did not independently predict follow-up outcomes. Conclusions Accurate prognostication after balloon pulmonary valvuloplasty depends on the careful determination of valvar anatomy. The use of an appropriate ratio of balloon to valve hinge point diameter in the setting of typical valve morphology will optimize the chance of long-term success.