Echocardiographic Markers for the Prediction of Nonclosure of the Patent Ductus Arteriosus in Premature Neonates

Abstract

Four echocardiographic markers—left ventricular ejection fraction (LVEF), the ratio of the left atrial diameter to the aortic root diameter (LA/Ao), the ratio of the patent ductus arteriosus (PDA) diameter to the left pulmonary arterial diameter (PDA/LPA), and the patent foramen ovale (PFO) diameter—were explored to predict a PDA in 221 premature neonates (53% male). There were 182 cases with PDA (mean diameter = 2.49 mm); 39 control subjects were observed with a closed ductus arteriosus. Although 104 of the cases (57.1 %) were diagnosed when 0 to 3 days old (median age = 1 day), 78 (42.9%) were diagnosed when 4 to 86 days old (median age = 13 days). Birth weights of the neonates ranged from 0.5 to 4.8 kg (mean = 1.68 kg). After controlling for age and birth weight, the mean LVEF (%) was not significantly different in the cases versus controls ( P > .05); the mean LA/Ao and mean PFO diameter were significantly larger ( P < .001) in the cases. The mean PDA/LPA was consistently ≥ .7 in the cases. The sensitivity of the LA/Ao ratio as a positive test for PDA (cutoff = 1.5) varied with age but not birth weight. When the neonatal age was 0 to 3 days, the sensitivity was 56% with a specificity of 88%; when the neonatal age was > 3 days, the sensitivity of LA/Ao was 82% with a specificity of 63%. The sensitivity of PFO (cutoff = 3.0 mm) was 61% with a specificity of 48%, irrespective of age or birth weight. These data suggest that LVEF is not a significant predictor of the presence of PDA, but a combination of the LA/Ao ratio, PDA/LPA ratio, and PFO diameter is predictive of the presence of PDA.