While atrial granules that looked like secretory vesicles were described in the 1950s it was only in the late 1980’s that B-type natriuretic peptide (BNP) was discovered. We now know that natriuretic peptides exist as a family of peptides. BNP acts on a GTP coupled receptors to exert its biologic functions. Natriuretic peptides lower blood pressure, increase sodium excretion, and decrease aldosterone and vascular smooth muscle proliferation. The natriuretic peptides and their breakdown products have been measured in blood and are powerful predictors of heart failure and death.
The natriuretic peptide assays are well established and available on major analysers. The diagnostic performance in the detection of heart failure is high. Randomised controlled trials have been difficult and show only a small effect (if any) on admission rates and length of stay of these patients. Use for BNP/NTproBNP (N-terminal pro BNP) levels in the management of patients with known heart failure show in some studies that all-cause mortality on BNP-guided therapy reduced compared to a clinically guided group. This was not true for patients older than 75 years. Perhaps the diagnostic testing of natriuretic peptide levels has most benefit for the optimization of the treatment of patients with heart failure. The use of BNP as a treatment for heart failure has not been successful.