Amino-Terminal Pro–B-Type Natriuretic Peptide Testing for the Diagnosis or Exclusion of Heart Failure in Patients with Acute Symptoms

When used for the evaluation of patients with acute symptoms in the emergency department setting, amino-terminal pro–B-type natriuretic peptide (NT-proBNP) testing is highly sensitive and specific for the diagnosis or exclusion of acute destabilized heart failure (HF), with results comparable to those reported for B-type natriuretic peptide (BNP) testing. When used for the diagnostic evaluation of the patient with possible HF, NT-proBNP testing returns information that may be superior to clinical judgment. However, the optimal application of NT-proBNP is in concert with history and physical examination, adjunctive testing, and with the knowledge of the differential diagnosis of an elevated NT-proBNP level. Studies indicate a dual use for NT-proBNP, both to exclude acute HF (where NT-proBNP concentrations <300 ng/L have a 98% negative predictive value), as well as to identify the diagnosis. To identify acute HF in patients with dyspnea, an age-independent NT-proBNP cut point of 900 ng/L has a similar value as that reported for a BNP value of 100 ng/L. However, age stratification of NT-proBNP using cut points of 450, 900, and 1,800 ng/L (for age groups of <50, 50–75, and >75 years) reduces false-negative findings in younger patients, reduces false-positive findings in older patients, and improves the overall positive predictive value of the marker without a change in overall sensitivity or specificity. Clinically validated, cost-effective algorithms for the use of NT-proBNP testing exist. Therefore, the logical use of NT-proBNP for the evaluation of the patient with suspected acute HF is useful, cost-effective, and may reduce adverse outcomes compared with standard clinical evaluation without natriuretic peptide testing.