Background and Aim The role of N terminal pro- B type natriuretic peptide (NT-pro-BNP) to differentiate cardiac and respiratory causes of dyspnea in adults has been previously investigated. This study is conducted in order to evaluate the diagnostic value of this peptide in differentiating between cardiac and respiratory causes of neonatal respiratory distress.
Methods A prospective case-control study was conducted on 30 neonates >34 weeks gestational age, presenting with signs of respiratory distress who were evaluated clinically and underwent NT-pro-BNP assay on the 4th and on the 10th days of life if respiratory symptoms continued. Echocardiography was performed for all cases and accordingly classified into cardiac and respiratory problems (CP&RP) groups based on the presence of significant cardiac defects. The control group included 17 healthy neonates.
Results Each of the CP and RP groups included 15 infants. The mean value of NT-pro-BNP was significantly higher in the CP group than the RP group on the 4th day of life. The best calculated cut-off point was 196.4 fmol/L (95% CI 61.7–95.2%, sensitivity of 73.3% and specificity of 64.3%). A level of 127fmol/L could be used to rule out cardiac disease (sensitivity of 100% and specificity of 37%). A level of 480 fmol/L can be used to rule in cardiac disease (sensitivity of 46% and specificity of 100%). In between these 2 levels, there is a grey zone with 5 cases (33.3%).
Conclusions NT-pro-BNP levels can be a useful biomarker to identify neonates with cardiac problems.