Is NT-proBNP an early predictor of bronchopulmonary dysplasia? A competing risk analysis

Purpose To evaluate whether N-terminal pro-brain natriuretic peptide (NT-proBNP) measured at 48–72 hours of life predict moderate-to-severe bronchopulmonary dysplasia (msBPD) using a competing risk framework. Methods We conducted a prospective cohort study including infants ≤ 32 weeks of gestation admitted between 2013–2023 to a level III neonatal unit. NT-proBNP was routinely measured at 48–72 hours. Primary outcomes were msBPD (2001 NIH definition) and death before 36 weeks postmenstrual age, analyzed using Fine and Gray competing risk regression. Secondary analyses included cumulative incidence of successful extubation by day 28 and sensitivity analyses restricted to infants surviving beyond 14 days. Models were adjusted for gestational age (GA) and other clinically relevant covariates. Results Among 264 included infants with a median (IQR) gestational age and birth weight of 30 [27.5–31.5] weeks and 1230 [981–1568] g) respectively, 38 (14.4%) developed msBPD and 18 (6.8%) died. NT-proBNP was not associated with msBPD in univariate [subdistribution hazard ratio (SHR) 1.03, 95% confidence interval (CI) 0.79–1.34; p = 0.84] or adjusted models. Conversely, NT-proBNP independently predicted death [adjusted SHR 2 (95% CI 1.2–3.2); p = 0.008). NT-proBNP was also associated with a reduced chance of successful extubation [adjusted SHR 0.88, (95% CI 0.8–0.98); p = 0.027). In infants surviving > 14 days, NT-proBNP showed a modest association with msBPD [adjusted SHR 1.3 (95% CI 1.01–1.73); p = 0.042). Conclusion Early NT-proBNP is primarily a marker of early mortality risk rather than a specific predictor of msBPD. Competing risk methods are essential to avoid overestimating biomarker utility in bronchopulmonary dysplasia (BPD) prediction.