Predictors of failed closure of patent ductus arteriosus with indomethacin

Boo NY, Mohd-Amin I, Bilkis AA, Yong-Junina F
Correspondence: Professor Nem-Yun Boo, nemyun_boo@imu.edu.my

ABSTRACT
Introduction The aim of this study was to determine predictors of failed closure of patent ductus arteriosus (PDA) following a single course of indomethacin in symptomatic preterm infants.
Methods This prospective observational study was carried out on 60 preterm infants weighing less than 1,750 g with symptomatic PDA confirmed by echocardiography. At a median age of 7.0 days (interquartile range 4.0), they were given indomethacin of 0.1 mg/kg/day intravenously daily for six days. Closure of PDA was reassessed by echocardiography upon completion of therapy.
Results The PDA of 40 percent (n=24) of these infants remained patent. Forward logistic regression analysis showed that the only significant predictors of failed PDA closure in these infants were: PDA size (adjusted odds-ratio [OR] is 7.0; 95 percent confidence interval CI] of OR is 2.0, 24.8; p-value is 0.002), birth weight (adjusted OR is 0.996; 95 percent CI of OR is 0.993, 1.000; p-value is 0.03) and platelet count (adjusted OR is 0.987; 95 percent CI is 0.975, 1.000; p-value is 0.045). Gestational age, maternal age and left atrium/aorta ratios were not significant predictors.
Conclusion Larger PDA, lower birth weight and lower platelet count were significant predictors of high failure in indomethacin therapy given late at one week of life.

Keywords: indomethacin therapy, patent ductus arteriosus, preterm infants
Singapore Med J 2006; 47(9): 763-768