Indomethacin Impairs Coronary Perfusion in Infants with Hemodynamically Significant Ductus Arteriosus

Background: A haemodynamically significant ductus arteriosus (HSDA) is commonly associated with morbidity in preterm infants. Aim: To study the effect of the first dose of indomethacin on coronary blood flow in preterm neonates diagnosed with an HSDA. Method: A prospective observational echocardiographic study was performed on preterm infants. A single study dose of intravenous indomethacin (0.1 mg/kg) was administered over 1 h. Serial echocardiography was performed before and after indomethacin treatment to study the effect on coronary artery perfusion and cardiovascular performance. Results: Eighteen infants born at a median gestation of 25.8 (24.2, 28.1) weeks and a birth weight of 773 g (704, 1,002) were evaluated. The median age at indomethacin administration was 7.5 days (4, 17). There was no significant change in arterial pressure or ventilatory indices. Left anterior descending artery diastolic velocity and time integral declined from 0.3 ± 0.1 and 3.19 ± 1.2 m/s to 0.22 ± 0.08 and 2.01 ± 0.9 m/s, respectively, within 10 min of completion of infusion. These indices showed partial recovery when reassessed after 60 min. There were no changes in left ventricular output or transductal flow. Conclusions: Intravenous indomethacin was followed by a decline in coronary arterial diastolic blood flow.