Failure of Ductus Arteriosus Closure Is Associated With Increased Mortality in Preterm Infants

Abstract

OBJECTIVE. Because the standard of care has been to attempt to close the patent ductus arteriosus in preterm neonates, there is a paucity of information on the outcome of patients with a persistent patent ductus arteriosus. Our objective was to compare the mortality of preterm infants with and without a persistent patent ductus arteriosus. METHODS. This was a single-center, retrospective study. Very preterm infants (birth weight ≤ 1500 g and gestational age ≤ 29 weeks) who survived beyond the first 3 postnatal days and did not undergo surgical ligation were included in the primary analysis. Mortality of neonates with a persistent and a closed patent ductus arteriosus was compared during the initial hospitalization by using the χ2 test. Cox proportional hazard regression and logistic regression were used to take into account the time until death and assess the independent effect of each risk factor on mortality. We also performed 3 secondary analyses by excluding patients who died during the first 7 and 14 postnatal days and including patients who underwent surgical ligation by using different group assignments. A persistent patent ductus arteriosus was defined as a failure of either spontaneous or pharmacologic ductal closure during the initial hospitalization. RESULTS. Patients with a persistent patent ductus arteriosus (n = 41) had lower birth weight and were less mature than those with a closed ductus (n = 260). Unadjusted mortality rate was higher in patients with a persistent (70.7%) than with a closed (11.2%) ductus. After adjustment for perinatal factors, level of maturity, disease severity, and morbid pathologies, the hazard for death in neonates with a persistent ductus was eightfold higher than in those with a closed ductus. Exclusion of patients who died during the first 2 weeks or inclusion of those who underwent ductal ligation did not change the findings. CONCLUSION. Failure of ductal closure is associated with an increase in mortality in very preterm infants.