Association between hemodynamically significant patent ductus arteriosus and bronchopulmonary dysplasia

Objective: To assess whether the duration and magnitude of the shunt with patent ductus arteriosus (PDA) are related to a higher incidence of bronchopulmonary dysplasia (BPD) or death. Study design: A total of 242 infants ≤28weeks gestational age were evaluated retrospectively between 2007 and 2012; 105 (43.3%) developed BPD or died (group 1) and 137 (56.6%) did not (group 2). A review of all echocardiographic evaluations performed from birth up to 36weeks of postconceptional age or final ductal closure was carried out, to detect the presence of PDA, and estimate the severity of ductal shunt through the "PDA staging system" proposed by McNamara and Sehgal. Results: Group 1 presented with a hemodynamically significant ductus arteriosus (DA) (E3 and/or E4-PDA) for a longer period of time vs group 2: 4.8 vs 2.3days, respectively (P<.001). Persistence of a nonsignificant DA (E2) was not associated with development of BPD (P=.16). Each week of a hemodynamically significant DA represented an added risk for BPD (OR 1.7), and the duration of a small, nonsignificant DA (E2) did not. Surgical ligation of PDA itself was not found to be an independent risk factor for BPD. In the subgroup of patients who received ligation, a later ligation (33 vs 23days) and a prolonged PDA were the only factors associated to BPD or death. Conclusions: A shared scoring system of the severity of ductal shunt is helpful to correctly evaluate the association between PDA morbidities, to compare scientific studies, and to guide treatment.