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

metabolism and renal excretion.The clearance of BNP depends on neutral endopeptidase-dependent degradation and receptor-mediated degradation. 8BNP acts as an active hormone with vasodilatory and diuretic effects that reduce left ventricular (LV) overload. 9In contrast, NT-proBNP is excreted from the kidney without any metabolism and has a longer half-life than BNP. 10 Despite these differences, both BNP and NT-proBNP are useful biomarkers for the identification of HF patients with a high risk of cardiac events. 5,11Natriuretic peptide level is affected by several factors including age, gender, obesity, anemia and kidney function. 12-14All of these are major commodities in HF patients.Taking this into consideration, we hypothesized that the clinical significance of natriuretic peptides varies with the existence of commodities.We focused on CRAS, examining its association with natriuretic peptides.We also compared the prognostic abilities of BNP and NT-proBNP in HF patients with CRAS. Heart failure (HF) remains a major and increasing public health problem, with a high mortality rate. 1 Recent reports indicate that cardio-renal anemia syndrome (CRAS) is closely associated with extremely poor outcomes in patients with HF. 2-4 HF, chronic kidney disease (CKD) and anemia could be exacerbated by each other.Cardiac biomarkers are generally used for the diagnosis or severity assessment of heart disease. 5,6Natriuretic peptides are synthesized and released from the atrial and ventricular myocardium after the precursor pro-brain natriuretic peptide (BNP) is cleaved into the hormonally active BNP and inactive N-terminal (NT)-proBNP in response to cardiomyocyte stimulation, such as, volume overload, pressure overload, and ischemic injury. 7Therefore, BNP and NT-proBNP are produced at equimolar levels at first.