Natriuretic Peptides in Patients with Heart Failure
Cleavage of the prohormone proBNP (B-type natriuretic peptide) produces biologically active 32 amino acid BNP and biologically inert 76 amino acid N-terminal pro-BNP (NT-proBNP). Atrial natriuretic peptide (ANP) is a hormone that is released from myocardial cells in the atria, and in some cases the ventricles in response to volume expansion. The circulating concentration of BNP is less than 20% of that of ANP in normal subjects but can equal or exceed that of ANP in patients with heart failure (HF). The wider range of concentrations makes BNP a more useful measurement than ANP in the evaluation of patients with HF, thus there is more clinical experience with BNP. Mid- regional pro-atrial natriuretic peptide (MR-proANP) is available at some specialised institutions.