N-terminal Pro-B-type Natriuretic Peptide: A measure of significant Patent Ductus Arteriosus

Abstract

Background: B type natriuretic peptide (BNP) is a marker for ventricular dysfunction secreted as a pre-prohormone, Pro-B-type natriuretic peptide (ProBNP), and cleaved into BNP and a biologically inactive fragment, N-terminal pro-B-type natriuretic peptide (NT-proBNP). Little is known about the clinical usefulness of NT-proBNP in preterm infants.

Objective: To evaluate the usefulness of plasma NT-proBNP in diagnosing hsPDA in neonates and examine some factors that could affect this.

Methods: Infants born at <34 weeks gestation (GA) and < 2kg birth weight (BW) were prospectively enrolled within 6 to 12 hours of birth. Plasma NT-proBNP levels were measured on days 1, 3, 5 and 10 with simultaneous echocardiography done to detect hsPDA and assess ventricular function. Significant PDA diagnosed by large ductal flow with left to right shunt on colour Doppler measuring >1.6mm on 2D echocardiography along with clinical features of PDA.

Results: Forty-nine infants analysed. Median GA 30 weeks (range: 24-33) and median BW 1220 grams (range: 550-1950gm). Eighteen hsPDA infants had higher day 3 plasma NT-proBNP values (median 32907pg/mL; range: 11396-127155) (p<0.001) compared with controls (median 3147pg/mL; range: 521-10343). Infants who developed sepsis had higher day 10 plasma NT-proBNP levels. Area under ROC curve for detection of hsPDA, by day 3 NT-proBNP value, was significant 0.978 (95% CI: 0.930-1.026). NT-proBNP was predictive of hsPDA (sensitivity 100%; specificity 95%) at cut-off value of 11395pg/mL.

Conclusion: Plasma NT-proBNP level on day 3 is a good marker for hsPDA in preterm infants. Serial measurements of NT-proBNP may be useful in assessing the clinical course of PDA.