[Value of amino-terminal pro-brain natriuretic peptide as a predictive marker of symptomatic patent ductus arteriosus in preterm infants].

Objective: To study the value of amino-terminal pro-brain natriuretic peptide (NT-proBNP) in predicting symptomatic patent ductus arteriosus (sPDA) in preterm infants.

Methods: Preterm infants born at a gestational age (GA) of ≤ 32 weeks and diagnosed with patent ductus arteriosus (PDA) by echocardiography within 48 hours after birth between June 2014 and April 2015 were selected as subjects. Their clinical manifestations were observed, and serum NT-proBNP levels were measured and echocardiography was performed at 3 and 5 days after birth. The infants were divided into sPDA group and asymptomatic PDA (asPDA) group based on their clinical manifestations and the results of echocardiography. The correlations between serum NT-proBNP level and echocardiographic indices were analyzed. Serum NT-proBNP levels were compared between the two groups. The receiver operator characteristic (ROC) curve was applied to determine the sensitivity and specificity of serum NT-proBNP in the prediction of sPDA.

Results: A total of 69 preterm infants were enrolled in this study, with 13 infants in the sPDA group and 56 infants in the asPDA group. Serum NT-proBNP level was positively correlated with the diameter of the arterial duct (r=0.856; P<0.05)and the ratio of left atrial diameter to aortic root diameter (LA/AO) (r=0.713; P<0.05). At 3 and 5 days after birth, the serum NT-proBNP levels in the sPDA group were significantly higher than those in the asPDA group (P<0.05). The area under the ROC curve (AUC) for the prediction of sPDA by NT-proBNP levels at 3 days after birth was 0.949 (95% CI: 0.892-1.000; P<0.001), with a cut-off value of 27 035 pg/mL (sensitivity: 92.3%; specificity: 94.6%); the AUC for the prediction of sPDA by NT-proBNP levels at 5 days after birth was 0.924 (95% CI: 0.848-1.000; P<0.001), with a cut-off value of 6 411 pg/mL (sensitivity: 92.3%; specificity: 92.9%).

Conclusions: NT-proBNP may be a quantitative index for shunt volume. The measurement of serum NT-proBNP levels on 3 and 5 days after birth may be useful to predict sPDA in preterm infants.