Do Elevated BNP Levels Predict Hemodynamically Significant PDAs

The purpose of this study is to determine if B type natriuretic peptide (BNP) levels can be used to predict a hemodynamically significant patent ductus arteriosus (PDA). This peptide is produced by the ventricles in the heart when they are under stress, such as when a ductus remains open. If we can use a simple and inexpensive blood test to determine whether a PDA needs to be treated, we can potentially treat infants sooner than if they needed to wait for the availability of a cardiologist to perform an echocardiogram. This might decrease some of the deleterious effects of PDAs on the preterm infant such as bronchopulmonary dysplasia, necrotizing enterocolitis, renal hypoperfusion, and pulmonary hemorrhage. In a situation where follow up echocardiogram after a course of medical therapy shows persistent PDA, this test may help to decide whether this baby needs further treatment, either medical or surgical.