EDN1 and bronchopulmonary dysplasia: In summary, infants experiencing the primary endpoint (group A) had significantly higher NTproBNPZlog levels at T1 and T2 compared to group B. Additionally, ET-1 levels differed significantly at T1 between subgroups, with higher values in group A. Only at T1 blood samples of ET-1 were available (n = 35; no-BPD = 23; BPD = 12).