Abstract
Children with single ventricle (SV) physiology have increased ventricular work and are at risk of heart failure (HF). However, a HF diagnosis is especially difficult, because few objective measures of HF have been validated in this cohort. We have previously shown that plasma B-type natriuretic peptide (BNP) levels are sensitive and specific for detecting HF in a small, heterogeneous SV cohort. The aim of the present study was to define the effect of SV morphology and stage of palliation on the correlation between BNP and HF. We also examined the utility of N-terminal pro-BNP (NT-proBNP), a more stable product of pre-BNP processing, as a biomarker of HF in these patients. A cross-sectional observational study of SV children aged 1 month to 7 years was conducted. The presence of HF was defined as a Ross score > 2. The association of BNP or NT-proBNP with HF was assessed using logistic regression analysis and receiver operating characteristic curves. Of the 71 included children, 22 (31%) had clinical HF. A doubling of BNP was associated with an odds ratio for HF of 2.20 (95% confidence interval 1.36 to 3.55, p = 0.001) with a c-statistic > 75%, yielding a detection threshold of ≥ 45 pg/ml. This threshold was preserved when patients were stratified by the right ventricular morphology or stage of surgical palliation. Similarly, a doubling of NT-proBNP was associated with an odds ratio for HF of 1.92 (95% confidence interval 1.17 to 3.14, p = 0.009). In contrast to BNP, the threshold value of NT-proBNP for predicting HF decreased with the stage of palliation. In conclusion, plasma BNP and NT-proBNP are reliable tests for clinical HF in young children with SV physiology, specifically those with right ventricular morphology, regardless of the stage of palliation.