Age at death in the hypoplastic left heart syndrome: Multivariate analysis and importance of the coronary arteries

Survival analysis of 63 fatal cases of the hypoplastic left heart syndrome was undertaken to determine whether morphologic measurements related to coronary blood flow would predict the length of postnatal survival. Cross-sectional areas of the ascending aorta and proximal left and right coronary arteries, left and right ventricular mass, coronary artery dominance pattern, and the presence of discrete coarctation were determined from autopsy specimens. These values were used to construct survival functions using Cox regression. Survival was significantly prolonged in cases with larger cross-sectional areas of the left ( p < 0.005) and right ( p < 0.05) coronary arteries, right ventricular mass ( p < 0.005), and combined ventricular mass ( p < 0.005). A multivariate model was developed that included combined left and right coronary artery cross-sectional areas, right ventricular mass, and the ratio of combined coronary artery area-to-combined ventricular mass. This model also significantly ( p < 0.001) predicted instantaneous risk of death, and again larger covariate values were associated with longer survival. These results suggest that myocardial perfusion is an important determinant of survival in these infants.