N Terminal Pro B Type Natriuretic Peptide as a marker of severity of heart failure in children with Congenital Heart Disease

Background: N Terminal Pro B Type Natriuretic Peptide (NT pro BNP) has been used as a tool for diagnosis, severity assessment and prognostication of congestive heart failure 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 pro BNP as a marker of heart failure severity and prognostication. So, this study was done to assess the utility of NT pro BNP as a marker of severity of heart failure in children with congenital heart diseases Settings and Design: Single centre, prospective observational study. Methods: Children (1month to 5 years), with congenital heart disease, admitted in the paediatric wards with varying severity of congestive heart failure (CHF) were enrolled. Heart failure severity grading was done according to Lair 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). Within 24 hours of admission, NT pro BNP levels were measured within 24 hours of admission. Results: 80 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 pro BNP 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 – 11857 pg/ml) and 11320.34 pg/ml respectively. 7 children (8.75%) expired. Median NT pro BNP value in 7 children who died was significantly higher than those who survived [median (IQR): 11681.01pg/ml (10092.72-14754pg/ml) vs 839.4 pg/ml (456.67-3288.09 pg/ml), p value<0.001]. NT pro BNP level of 520.2pg/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. Conclusion: NT pro BNP levels increase progressively with increasing severity of congestive heart failure and can be used as a marker of severity of heart failure in children with congenital heart disease presenting with CHF