100 - Accuracy of NT pro-BNP in Diagnosis of Chronic Pulmonary Hypertension in Extremely Low Gestational Age Neonates

Poster Number: 100
Publication Number: 100.426

Macarena Garcia Gozalo, University of Toronto Temerty Faculty of Medicine, Toronto, ON, Canada; Amish Jain, University of Toronto Temerty Faculty of Medicine, toronto, ON, Canada; Bonny Jasani, The Hospital for Sick Children, Toronto, ON, Canada; Dany E. Weisz, University of Toronto Temerty Faculty of Medicine, Toronto, ON, Canada

Background: Bronchopulmonary dysplasia (BPD) associated chronic pulmonary hypertension (CPH) is associated with increased mortality and morbidity among extremely low gestational age neonates (ELGANs: < 276/7 gestation at birth). Echocardiography (ECHO) is the modality of choice for diagnosis of CPH and screening is recommended at approximately 35-40 weeks postmenstrual age (PMA). N terminal-pro brain natriuretic peptide (NT pro-BNP) is a known biomarker of right ventricular (RV) pressure overload, as occurs in CPH, though few studies have evaluated its diagnostic accuracy among ELGANs.

Objective: To determine the diagnostic accuracy of serum NT pro-BNP serum among ELGANs

Design/Methods:

We conducted a retrospective cohort study of ELGANs with high risk of moderate to severe bronchopulmonary dysplasia (BPD) who were screened for CPH with paired ECHO and serum NT-proBNP concentrations between 34-40 weeks PMA at a quaternary neonatal intensive care unit (NICU) from October 1, 2020- September 30, 2022. CPH was diagnosed on ECHO as the presence of at least one of the following: RV systolic pressure (RVSP) > 35 mmHg; flat interventricular septum at end systole and right ventricular dilatation. Patient demographics as well as perinatal and postnatal data including echocardiographic details and NT-proBNP concentrations were retrieved from electronic medical records. The accuracy of NT-proBNP and key clinical characteristics in the diagnosis of CPH was evaluated using the receiver operating characteristics curve (ROC). Youden’s index was estimated to identify the optimal NT-proBNP cut-off for CPH diagnosis.

Results:

Among 63 eligible ELGANs, 33 were screened with paired ECHO and NT-proBNP (14 with CPH and 19 with no CPH). The baseline characteristics and outcomes of included infants are shown in Table1. NT-proBNP was an acceptable predictor of CPH (AUC 0.7, 95% CI 0.51 to 0.89), however the combination of NT-proBNP and gestational age < 25 weeks had excellent discriminatory ability (AUC 0.80, 95% CI: 0.64 to 0.95) (Figure 1). The inclusion of the severity of BPD in the multivariable model did not improve model discrimination. Serum NT-proBNP concentration of ≥ 1190 ng/L had 58% sensitivity and 86% specificity for diagnosing CPH.

Conclusion(s): Serum NT pro-BNP concentrations differ between CPH and non-CPH infants and in combination with gestational age has excellent discriminatory ability to detect CPH, and may be useful among centres among whom access to echocardiography is limited. Future studies should examine the utility of NT pro-BNP for longitudinal monitoring of CPH and response to treatments.