Closure of Hemodynamically Significant Patent Ductus Arteriosus and Factors Associated with Treatment Failure with Paracetamol

Objective: There is a scarcity of data on the factors associated with nonresponders to paracetamol for closure of hemodynamically significant patent ductus arteriosus (hsPDA). This study aims to determine the failure rate and to identify factors associated with nonresponders to acetaminophen to close hsPDA. Methods: This retrospective, observational cohort study involved all inborn delivered at ≤ 32 weeks and birth weight of < 1.5 kg who had hsPDA. A multivariable logistic regression model was used to identify factors associated with nonresponders to paracetamol. Results: There were 137 hsPDA patients with a mean birth weight, gestational age, and age of diagnosis of 1027.9 ± 209.2 g, 28.1 ± 2.1 weeks, and 12.0 ± 7.2 days. The mean dimension of hsPDA, left atrium to the aorta, and PDA to left pulmonary artery ratio was 3.03 ± 0.64 mm, 1.94 ± 0.41, and 1.02 ± 0.17, respectively. The nonresponders to paracetamol was 18.2% (95% confidence interval [CI]: 12.4-25.9) and was significantly associated with bronchopulmonary dysplasia (BPD) (15/25 vs. 16/112, p<0.001) and interventricular hemorrhage (IVH) (13/25 vs. 31/112, p=0.02). Factors associated with nonresponders were a PDA to left pulmonary artery ratio (LPA) > 1.0 and ventilation at diagnosis with adjusted odds ratios of 6.69 and 4.17, respectively. Conclusions: One in five infants with hsPDA did not respond to treatment and were significantly associated with BPD and IVH. Invasive ventilation at diagnosis and a PDA to LPA ratio of > 1 were associated with treatment failure. Hence, different strategies are needed in this group of hsPDA.