Serial measurements of serum NT-proBNP as markers of left ventricular systolic function and remodeling in children with heart failure

Background Increasing serum levels of N-terminal pro-hormone brain natriuretic peptide (NT-proBNP) are associated with worsening heart failure (HF) in adults. We determined whether changes in NT-proBNP level are associated with changes in symptoms and left ventricular (LV) systolic function and remodeling in children with HF secondary to dilated cardiomyopathy. Methods We retrospectively examined associations between serum NT-proBNP levels and NYHA/Ross functional class, LV systolic and diastolic diameter (LVSD-z and LVDD-z), LV ejection fraction (LVEF), and LV shortening fraction (LVSF-z) using generalized linear mixed models. Fluctuation in functional class of subjects was also modeled using logistic regression and receiver operating characteristic (ROC) curves. Results In 36 children (14 males), a 10-fold increase in NT-proBNP serum levels was associated (P < .001) with a 9.8% decrease in LVEF, a 3.25-unit drop in LVSF-z, a 1.53-unit increase in LVDD-z, a 2.64-unit increase in LVSD-z, and an increased odds of being in functional class III/IV (OR 85.5; 95% CI, 10.9 to 671.0). An NT-proBNP level greater than 1000 pg/mL identified children constantly or intermittently in functional class III-IV with 95% sensitivity and 80% specificity. The reliability of a single NT-proBNP value was 0.61, but the means for two and three NT-proBNP values were 0.76 and 0.82, respectively. Conclusions In children with HF, NT-proBNP is associated with cardiac symptoms and indices of LV systolic dysfunction and remodeling. NT-proBNP > 1000 pg/mL identifies highly symptomatic children. Within subject serial measurements of NT-proBNP are needed for a reliable and accurate determination of disease status and/or course. (Am Heart J 2010;160:776-83.)