Brain Natriuretic Peptide: Structure, Action and Role in the Diagnosis and Prognosis of Heart Failure

Brain natriuretic peptide (BNP) is a peptide hormone secreted by cardiomyocytes in response to atrial or ventricular wall stretch. It promotes a number of systemic effects, including vasodilatation, increase in urinary output and sodium excretion as well as inhibition of the sympathetic nervous system and the renin–angiotensin–aldosterone system. Plasma BNP levels have been reported to be elevated in patients with left ventricular hypertrophy, congestive heart failure, acute coronary syndromes, atrial fibrillation and impaired renal function. Moreover, elevated BNP levels have been shown to be a strong predictor of morbidity and mortality in patients with heart failure. Interestingly, it has also been found that the N-terminal peptide of BNP is slightly superior to BNP for predicting death or re-hospitalization for heart failure. Presumably, it is the longer half-life of NT-pro-BNP that may promote it as a more accurate index of ventricular stress and therefore a better predictor of prognosis.