Clinical applications of B-type natriuretic peptide levels in the care of cardiovascular patients.

B-type natriuretic peptide (BNP), is a cardiac neurohormone, and is released as prepro BNP and then enzymatically cleaved to the N-terminal-proBNP and BNP upon ventricular myocyte stretch. Blood measurements of BNP have been used to identify patients with heart failure (HF). The BNP assay is currently used in diagnosis, prognosis, screening, and response to treatment for patients with HF. In general, a BNP level below 100 pg/mL excludes acutely decompensated HF and levels > 500 pg/ml indicate decompensation. There are supportive data for using BNP to guide both inpatient and outpatient HF diagnosis and treatment. When BNP is elevated in acute coronary syndromes, pulmonary embolism, and sepsis, it implies that subclinical left ventricular dysfunction is present and a higher mortality rate can be expected. Elevated BNP levels before cardiac surgery are associated with higher rates of atrial fibrillation and death. After bypass surgery, as left ventricular function improves, the BNP level can be expected to fall. Lastly, in patients with aortic stenosis, aortic regurgitation, and mitral regurgitation, BNP elevates and is associated or may precede the development of symptoms and possibly can serve as a trigger for additional evaluation or intervention.