Role of Plasma B-Type Natriuretic Peptide in Screening for Hemodynamically Significant Patent Ductus Arteriosus in Preterm Neonates

Abstract

B-type natriuretic peptide (BNP) is a hormone secreted by the ventricles under hemodynamic stress and congestive failure. The objective of the present study was to evaluate whether BNP can be used as a valid screening test for the presence of a hemodynamically significant patent ductus arteriosus (hsPDA) in the preterm neonate. This was a prospective blinded study involving preterm neonates with birth weights <or=1500 g and gestational age <or=34 weeks. Each enrolled neonate underwent the initial echocardiogram for a clinical suspicion of patent ductus arteriosus (PDA) and BNP assay within 3 hours of each other. Those neonates who did not have a PDA or who were not treated underwent a repeat echo and BNP measurement 48 to 72 hours after the first echo. In patients who received treatment for a PDA, an echo and BNP were repeated 48 to 72 hours after completion of treatment. A total of 29 newborns with a median birth weight of 870 g (560 to 1325 g) and a median gestation of 26 weeks (24 to 31 weeks) were enrolled at a median age of 7 days (2 to 28 days). BNP levels were significantly higher in neonates with hsPDA (n=14) compared to those without (n=15) (508.5+/-618.2 vs 59.5+/-69.9 pg/ml, p<0.005). At a cutoff value of 70 pg/ml, BNP had a sensitivity of 92.9%, specificity of 73.3%, positive likelihood ratio of 3.5 and negative likelihood ratio of 0.09 for detection of hsPDA. BNP levels dropped significantly after medical or surgical closure of hsPDA (n=12), (404.9+/-159.2 to 25.1+/-4.1 pg/ml, p=0.03). Elevation of plasma BNP accurately detects the presence of hsPDA in premature infants. Successful closure is reflected by a corresponding decrease in BNP. At a cutoff of 70 pg/ml, BNP is a useful screening tool for diagnosis and for monitoring efficacy of treatment of hsPDA.