MIDTERM RESULTS OF BALLOON DILATION OF CONGENITAL AORTIC-STENOSIS - PREDICTORS OF SUCCESS

Objectives. We evaluated patient and procedural characteristics that i nfluence the midterm success of balloon dilation of congenital aortic stenosis. Background. Balloon dilation is a new treatment for congenit al aortic stenosis. Factors that influence midterm success are unknown . Methods. We performed a retrospective review of 148 children >1 mont h old who underwent balloon dilation for aortic stenosis. Results. Bal loon dilation was successful in 87% of patients, with a procedural mor tality rate of 0.7%, The average immediate peak to peak gradient reduc tion was 56.4 +/- 19.9% (mean +/- SD). Prior valvotomy was the only fa ctor that significantly reduced the immediate gradient reduction after dilation (47.1 +/- 21.8% vs. 57.8 +/- 19.6%, p < 0.01). Survival afte r dilation was 95% at 8 years. Seventy-five percent of patients were f ree of repeat intervention 4 years after dilation, whereas 50% remaine d free of repeat intervention at 8 years. Asymmetrically thick valve l eaflets (risk ratio [RR] 0.17, p < 0.01) and prior aortic valvotomy (R R 0.35, p = 0.02) decreased the risk of repeat intervention. Aortic re gurgitation grade greater than or equal to 3 (RR 4.27, p = 0.04) and r esidual gradient after dilation (RR 1.63 for 10 mm Hg, p < 0.01) incre ased the risk. Conclusions. The 8 year survival rate after dilation wa s 95%, with 50% of patients free of repeat intervention. Factors that increased the risk for repeat intervention included symmetrically thin or thick aortic valve leaflets, regurgitation grade greater than or e qual to 3 after dilation and a high residual gradient after dilation. The incidence of repeat intervention after dilation was high owing to its palliative nature.