N-Terminal Pro-B-Type Natriuretic Peptide as a Marker of Severity of Heart Failure in Children with Congenital Heart Diseases

Abstract

N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been used as a tool for diagnosis, severity assessment and prognostication of congestive heart failure (CHF) in adults, with specific cut off values for diagnosis and denoting points of intervention. However, there is scarcity of paediatric literature regarding role of NT-proBNP as a marker of heart failure severity and prognostication. So, this study was done to assess the utility of NT-proBNP as a marker of severity of heart failure in children with congenital heart diseases. Single centre, prospective observational study. Children (1 month to 5 years), with congenital heart disease, admitted in the paediatric wards with varying severity of CHF were enrolled. Heart failure severity grading was done according to Laer modification of Ross Classification at the time of presentation to hospital and children were classified as having no/grade I CHF (score: 0-2); mild/grade II CHF (score 3-6); moderate/grade III CHF (score 7-9) or severe/grade IV CHF (score 10-12). NT-proBNP levels were measured within 24 h of admission. Eighty children with congenital heart disease were enrolled in this study. As per modified Ross Classification, 11 had grade I/No heart failure (13.7%), 32 children had grade II/mild heart failure (40%), 36 had grade III/moderate heart failure (45%) and only 1 had grade IV/severe heart failure (1.25%). The median NT-proBNP levels (IQR) in the above mentioned grades of heart failure were found to be 321.11 (211.1-411.78 pg/ml), 750.62 (474.62-995.2 pg/ml), 4159.61 (1440.59-11,857 pg/ml) and 11,320.34 pg/ml, respectively. Seven children (8.75%) expired. Median NT-proBNP value in seven children who died was significantly higher than those who survived [median (IQR): 11,681.01 pg/ml (10,092.72-14,754 pg/ml) vs 839.4 pg/ml (456.67-3288.09 pg/ml), p value < 0.001]. NT-proBNP level of 520.2 pg/ml predicted grade II (mild heart failure) or more severe grades of heart failure with Sensitivity, Specificity, Negative Predictive Value and Positive Predictive Value of 83%, 91%, 57.1% and 98%, respectively. NT-proBNP levels increase progressively with increasing severity of CHF and can be used as a marker of severity of heart failure in children with congenital heart disease presenting with CHF.

Keywords: Congenital heart disease; Congestive heart failure; Modified Ross Classification; NT-proBNP.