Fellow Physician Baylor College of Medicine Houston, Texas, United States
Background: The physiology seen in Congenital Diaphragmatic Hernia (CDH) is due to pulmonary hypoplasia, pulmonary hypertension, and cardiac dysfunction. Although following repair of the defect, there might be an improvement in the overall hemodynamic status, these patients can have clinical and echo signs of pulmonary hypertension (PH), necessitating PH therapy. While echo is the gold standard for assessing PH in these patients prior to repair, after repair, and for long-term follow-up, urinary biomarkers might offer the benefit of being quick, non-invasive and inexpensive. Objective: Our objective was to assess the utility of urinary NT-proBNP in the post-repair period in CDH and to investigate if urinary NT-proBNP levels could help predict the need for PH medications and respiratory support at discharge. Design/Methods: This is a pilot prospective observational study (IRB # H51324). Infants with parental consent and with a diagnosis of CDH born at >34 weeks of gestation and > 2000 grams will be included. Babies with lethal congenital anomalies, and without parental consent will be excluded. Urine samples will be collected with post-repair echo. Urinary NT-proBNP and its ratio to urinary creatinine (UNBCR) will be analyzed using VITROS 7600 ECi/ECiQ Immunodiagnostic Systems. Demographic and clinical data will be extracted from the electronic medical records of recruited patients. Logistic regression analysis will be used to assess the association of Urinary NT-proBNP (pg/dL) and UNBCR values with the need for pulmonary hypertension therapy and respiratory support at discharge. Receiver Operating Characteristic (ROC) curve analysis will be used to find the optimal cutoff for Urinary NT-proBNP (pg/dL) and UNBCR in predicting the need for pulmonary hypertension therapy (Treprostinil, Prostaglandins, Sildenafil or Bosentan) and respiratory support at discharge. Spearman’s correlation will be used to investigate the association of quantitative post-echo parameters with urinary NT-proBNP and UNBCR levels while the Kruskal-Wallis test will be used for categorical post-echo parameters.
