Urinary NT-proBNP and ductal closure in preterm infants.

OBJECTIVE

To explore the association of urinary N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations and closure of patent ductus arteriosus (PDA) in preterm infants.

STUDY

DESIGN

Blinded prospective study involving 136 preterm infants (median (interquartile range) gestational age 28 (26 to 30) weeks; birth weight 1030 (780 to 1270) g). NT-proBNP was determined in urine collected on day of life (DOL) 2, 7, 14 and 28.

RESULT: Urinary NT-proBNP/creatinine ratios declined continuously between DOL 2 (74 (17 to 248) μg g(-1)) and DOL 28 (4 (2 to 12) μg g(-1)) and were significantly elevated in ventilated infants on DOL 2, 7 and 14, and in ventilated infants with a hemodynamically significant PDA on DOL 2. Furthermore, urinary NT-proBNP/creatinine ratios on day 14 were higher in 14 ventilated infants who did not respond to pharmacological treatment and subsequently required surgical PDA closure (247 (214 to 547) μg g(-1)) than in ventilated infants (n=7) with successful pharmacological PDA closure (55 (21 to 114) μg g(-1); P<0.05). A cutoff >210 μg g(-1) on day 14 had a sensitivity of 75% and specificity of 100% for predicting non-responsiveness to pharmacological treatment.

CONCLUSION

Measurement of urinary NT-proBNP is a new and simple non-invasive test for preterm infants, which may be helpful in guiding PDA treatment decisions.