Determining the Optimal Cutoff Values of Plasma N-Terminal Pro B-Type Natriuretic Peptide Levels for the Diagnosis of Heart Failure in Children of Age up to 14 Years

Background: Plasma N-terminal fragment of pro B-type natriuretic peptide (NT-proBNP) is a biomarker of heart failure (HF). However, the optimal cutoff value of plasma NT-proBNP for the diagnosis of HF in children is unknown. The objective of this study was to determine the appropriate cutoff value of plasma NT-proBNP for the diagnosis of HF in children 14 years old. Methods and Results: Plasma NT-proBNP concentrations were detected in pediatric HF patients using standard clinical assays. Patients were stratified into 4 groups by age: 0-1 year, 1-3 years, 4-7 years, and 8-14 years. Case-matched healthy children were recruited as control subjects. HF was diagnosed with the use of the modified Ross score. The optimal cutoff value of plasma NT-proBNP for the diagnosis of HF was determined by analyzing receiver operating characteristic (ROC) curves and the resulting sensitivity, specificity, and Youden index (J). In healthy children, plasma NT-proBNP level and age were negatively correlated (r = 0.739; P < .001). In HF patients aged 0-1 year, 1-3 years, 4-7 years, and 8-14 years, respectively, areas under the ROC curves were 0.795, 0.786, 0.783, and 0.696; 95% confidence intervals were 0.689-0.901, 0.669-0.903, 0.662-0.904, and 0.487-0.905; and I values were 0.715, 0.708, 0.706, and 0.679. Optimal cutoff values of plasma NT-proBNP for the diagnosis of HF were 502 ng/L, 456 ng/L, 445 ng/L, and .355 ng/L. Conclusions: Age-stratified analysis of plasma NT-proBNP levels in children provides new parameters for diagnosing HF.