Critical aortic stenosis in the neonate: A multi-institutional study of management, outcomes, and risk factors

Objectives: We sought to determine factors that would predict whether a biventricular repair or Norwood procedure pathway would give the best survival in neonates with critical aortic stenosis. Methods: Survival and risk factors were determined with parametric time-dependent event analysis for patients undergoing either the Norwood procedure or biventricular repair, and predicted optimal pathway and survival benefit were derived from multivariable linear regression. Results: From 1994 to 2000, 320 neonates with critical left ventricular outflow obstruction were entered into a prospective multi-institutional study. Patients who died without intervention (n = 19) and those with primary cardiac transplantation (n = 6) were excluded. An initial intended biventricular repair pathway was indicated in 116 patients, with survival of 70% at 5 years. An initial Norwood procedure was performed in 179 patients, with survival of 60% at 5 years. Using predictions from separate multivariable hazard models for survival with each of the 2 pathways, we determined predicted optimal pathway and survival benefit for each patient. Significant independent factors associated with greater survival benefit for the Norwood procedure versus biventricular repair included younger age at entry, lower z-score of the aortic valve and left ventricular length, higher grade of endocardial fibroelastosis, absence of important tricuspid regurgitation, and larger ascending aorta. Predicted survival benefit favored the Norwood procedure in 50% of patients who had biventricular repair, and it favored biventricular repair in 20% of patients who had the Norwood procedure. Conclusions: Morphologic and functional factors can be used to predict optimal pathway and survival benefit in neonates with critical left ventricular outflow obstruction.