Canadian National PDA Treatment Study

Patent ductus arteriosus (PDA) is the most common cardiovascular problem that develops in preterm infants. Persistent PDA may result in higher rates of death, chronic lung disease (CLD), pulmonary hemorrhage, necrotizing enterocolitis (NEC), acute kidney injury (AKI), intraventricular hemorrhage (IVH) and cerebral palsy. Currently available options to treat a PDA include indomethacin, ibuprofen or acetaminophen followed by surgical or interventional closure of the PDA if medical therapy fails.

Wide variation exists in PDA treatment practices across Canada. A survey conducted through the Canadian Neonatal Network (CNN) in 2019 showed that the most common choice of initial pharmacotherapy is standard dose ibuprofen. In view of the high pharmacotherapy failure rate with standard dose ibuprofen, there is a growing use of higher doses of ibuprofen with increasing postnatal age (with 32% of respondents currently adopting this practice) in spite of the fact that effectiveness and safety of higher ibuprofen doses have not been established in extremely preterm infants [<29 weeks gestational age (GA)]. In view of this large practice variation across Canadian neonatal intensive care units (NICUs), we are planning a comparative effectiveness study of the different primary pharmacotherapeutic agents used to treat the PDA in preterm infants.

Aims Primary: To compare the primary pharmacotherapeutic practices for PDA closure and evaluate their impact on clinical outcomes in extremely preterm infants (<29 weeks GA) Secondary: To understand the relevance of pharmacotherapeutic PDA treatment with respect to clinical outcomes in the real world.

Methods:

Participants: Extremely preterm infants (<29 weeks gestational age) with an echocardiography confirmed PDA who will be treated according to attending team

Interventions:

1. Standard dose ibuprofen [10-5-5 regimen, i.e., 10mg/kg followed by 2 doses of 5mg/kg at 24h intervals] 2. Adjustable dose ibuprofen [10-5-5 regimen if treated within the first week. Higher doses of ibuprofen up to a 20-10-10 regimen if treated after the postnatal age cut-off for lower dose as per the local center policy] 3. Intravenous indomethacin [0.1-0.3mg/kg every 12-24h for a total of 3 doses]. 4. Acetaminophen [Oral/intravenous] (15mg/kg every 6h) for 3-7 days

Outcomes:

Primary: Failure of primary pharmacotherapy (Need for further medical and/or surgical/interventional treatment following an initial course of pharmacotherapy).

Secondary: (a) Receipt of 2nd course of pharmacotherapy; (b) Surgical/interventional PDA closure; (c) CLD (d) NEC (stage 2 or greater) (e) Severe IVH (Grade III-IV) (f) Definite sepsis (g) Stage 1 or greater AKI; (h) Post-treatment serum bilirubin; (i) Phototherapy duration; (j) All-cause mortality during hospital stay.