Age‐Dependent Sex Effects on Outcomes After Pediatric Cardiac Surgery

BACKGROUND: Sex has been linked to differential outcomes for cardiovascular disease in adults. We examined potential sex differences in outcomes after pediatric cardiac surgery. METHODS AND RESULTS: We retrospectively analyzed data from the Pediatric Cardiac Care Consortium (1982–2007) by using logistic regression to evaluate the effects of sex on 30‐day within‐hospital mortality after pediatric (<18 years old) cardiac operations and its interaction with age, risk category, z‐score for weight, and surgical year for the whole cohort. Of 76 312 operations, 55% were in boys. Unadjusted mortality was similar for boys and girls (5.2% versus 5.0%, P=0.313), but boys were more likely to have cardiac surgery as a neonate and to have more complex operations. After adjustment, the overall test of any association between postsurgical mortality and sex was significant (P=0.002), but the overall test of any interaction was not (P=0.503). However, a potential age‐dependent sex effect on postsurgical mortality was observed among infants subjected to high‐risk operations, with girls doing worse during the first 6 months of life. CONCLUSIONS: Patient sex has a significant effect on mortality after pediatric cardiac operations, with an increased risk of death in early infancy for girls after high‐risk cardiac operations. This age‐dependent relationship supports a sex‐related biological effect on postoperative cardiovascular stress.