In recent years biomarkers have emerged as important tools for diagnosis, risk stratification and therapeutic decision making in cardiovascular diseases. Cardiac troponins in particular have become the cornerstone for diagnostic work up of patients with acute coronary syndromes. Currently, several promising new biomarkers are under scientific investigation. Most of these new biomarkers, however, are not yet suitable for clinical application, with the exception of B-type natriuretic peptide (BNP) and its N-terminal fragment (NT-proBNP). Both markers have proven their diagnostic usefulness in a great number of studies and thus have progressed from bench to clinical application. This article aims to summarise existing data concerning BNP and NT-proBNP measurement in cardiovascular disorders and to outline how these markers can be integrated into clinical routine. Furthermore, future perspectives of these markers will be discussed.

PHYSIOLOGY

B-type natriuretic peptide, which is also called brain-type natriuretic peptide (BNP), was first described in 1988 after isolation from porcine brain. However, it was soon found to originate mainly from the heart, representing a cardiac hormone.

BNP belongs to the natriuretic peptide family together with other structurally similar peptides, namely atrial natriuretic peptide (ANP), C-type natriuretic peptide (CNP), and urodilatin. The natriuretic peptides have in common a characteristic biochemical structure which consists of a 17 amino-acid ring and a disulfide bridge between two cysteine molecules. The major source of BNP synthesis and secretion is the ventricular myocardium. Whereas ANP is stored in granules and can be released immediately after stimulation, only small amounts of BNP are stored in granules and rapid gene expression with de novo synthesis of the peptide is the underlying mechanism for the regulation of BNP secretion. BNP is synthesised as a prehormone (proBNP) comprising 108 amino acids. Upon release into the circulation it is cleaved in equal proportions into the biologically active 32 amino acid …