Plasma natriuretic peptides as predictors of hemodynamically significant patent ductus arteriosus in preterm neonates

ABSTRACT

The objective of this study was to determine whether the plasma levels of natriuretic peptides in preterm infants with patent ductus arteriosus [PDA] are predictors of the hemodynamic significance of the PDA shunt, and correlate them with clinical and echocardiographic assessment. Fifty preterm neonates, with a mean gestational age of 29.4 wk and weighing less than 1500 g, were enrolled in the study. Based on the clinical and echocardiographic findings, the hemodynamic influence of PDA shunt was classified as large [8 infants], moderate [10 infants], small [12 infants] or no PDA [20 infants]. Plasma N-terminal atrial natriuretic peptide prohormone [Nt-pro ANP] and brain natrituretic peptide [BNP] were assessed using ELISA kits. The results showed that plasma levels of Nt-pro ANP and BNP significantly increased with the size of PDA shunt, and when compared to infants without PDA [P<0.05]. A value of Nt-pro ANP > 5000 pmol/l predicted a hemodynamically significant PDA with a sensitivity of 97% and a specificity of 90%, whereas a value of BNP > 25 pmol/l had a sensitivity of 87% and a specificity of 75%. Using echocardiographic left atrial/aortic root ratio [LA Ao ratio] of 1.5 as a cut off gave a sensitivity of 75%. Using echocardiographic left atrial/aortic root ratio [LA Ao ratio] of 1.5 as a cut off gave a sensitivity of 80% and a specificity of 95%. There were significant positive correlations between these studied parameters [P<0.01]. Plasma naturiuretic peptides [Nt-pro ANP and BNP] can be used as predictors of the hemodynamic significance of PDA in preterm neonates, and their measurement may be regarded as complementary to echocardiography in the assessment of PDA shunt and institution of appropriate treatment. Nt-pro ANP is more sensitive and specific predictor than BNP