Serum levels of N-terminal pro-B-type natriuretic peptide are associated with allograft function in recipients of renal transplants
The aim of the present investigation was to evaluate the diagnostic accuracy of brain natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) for the detection of mild/moderate and severe impairment of left ventricular ejection fraction (LVEF). In 180 subjects BNP and NT-proBNP were measured by two novel fully automated chemiluminescent assays (Bayer and Roche methods). LVEF as determined by echocardiography was categorized as normal (> 60%), mildly/moderately reduced (35-60%) and severely diminished (< 35%). Discriminating between patients with LVEF< 35% (n = 32) and subjects with LVEF > or = 35% (n = 148), receiver-operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.912 for BNP and of 0.896 for NT-proBNP (difference 0.016, p = 0.554). In contrast, BNP displayed an AUC of 0.843 and NT-proBNP an AUC of 0.927 (difference of 0.084, p = 0.034) when comparing patients with LVEF 35-60% (n = 37) and individuals with LVEF > 60% (n = 111). Evaluation of discordant false classifications at cut-off levels with the highest diagnostic accuracy showed advantages for BNP in the biochemical diagnosis of LVEF < 35% (4 misclassifications by BNP and 25 by NT-proBNP, p < 0.001) and for NT-proBNP in the detection of LVEF 35-60% (25 misclassifications by BNP and 7 by NT-proBNP, p = 0.002). In conclusion, the present study indicates a different diagnostic accuracy of BNP and NT-proBNP for the detection of mildly/moderately reduced LVEF and severely diminished LVEF. Advantages of BNP may be advocated for the biochemical diagnosis of more severely impaired LVEF, while NT-proBNP might be a more discerning marker of early systolic left ventricular dysfunction.