B-type natriuretic peptide in ischemic heart disease.

B-type natriuretic peptide (BNP) and the N-terminal fragment of its prohormone (N-proBNP) are released from the heart in response to increased wall stress. Assays for these peptides are now commercially available, and measurement of BNP and N-proBNP is becoming commonplace in patients with suspected heart failure. BNP and N-proBNP facilitate diagnosis and risk stratification in patients with heart failure, and may help guide response to therapy. This review focuses on the emerging role of BNP and N-proBNP measurement in patients with acute coronary syndromes (ACS). Although experimental studies demonstrate rapid BNP release in response to cardiac ischemia, it is unlikely that BNP will be used to diagnose cardiac ischemia, because many other conditions are also associated with modest BNP elevation. In contrast, BNP holds tremendous promise as a prognostic marker in patients with ACS. Studies to date have shown consistently that higher BNP levels are associated with worse clinical outcomes, and that BNP provides unique information to clinical variables, other biomarkers, and left ventricular ejection fraction. Future studies are needed to identify the therapeutic implications of BNP elevation in patients with ACS.