Brain Natriuretic Peptide (BNP) and N-Terminal-proBNP in Cardio-Renal Anemia Syndrome　― Difference in Prognostic Ability ―

Background: Cardio-renal anemia syndrome (CRAS) is a growing health problem, with a high mortality rate. Brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are well-established diagnostic and prognostic biomarkers of heart failure (HF). The difference in the clinical significance of these biomarkers, however, has not yet been completely elucidated in HF. The aim of the present study was to compare the prognostic ability of BNP and NT-proBNP in HF patients with CRAS. Methods and Results: We measured BNP and NT-proBNP in 492 consecutive HF patients and in 17 control subjects. All patients were prospectively followed up during a median follow-up period of 1,034 days. NT-proBNP/BNP ratio was elevated in HF patients with CRAS compared with those without CRAS and the control subjects. There was no significant difference in the prognostic abilities of BNP and NT-proBNP in all HF patients. The C-index for NT-proBNP for predicting cardiovascular events and mortality, however, was significantly higher than that for BNP in HF patients with CRAS. On multivariate Cox proportional hazards-regression analysis, NT-proBNP, but not BNP, was an independent predictor for clinical outcome in HF with CRAS. Conclusions: The difference in the prognostic abilities of BNP and NT-proBNP was high in HF patients with CRAS. NT-proBNP had a superior prognostic ability to BNP in HF patients with CRAS.