Midregional Pro-A-Type Natriuretic Peptide Measurements for Diagnosis of Acute Destabilized Heart Failure in Short-of-Breath Patients: Comparison with B-Type Natriuretic Peptide (BNP) and Amino-Terminal proBNP

BACKGROUND: The aim of the present study was to assess the utility of amino-terminal pro-A-type natriuretic peptide (NT-proANP) measurements for the emergency diagnosis of acute destabilized heart failure (HF), using a novel sandwich immunoassay covering midregional epitopes (MR-proANP). METHODS: The retrospective analysis comprised 251 consecutive patients presenting to the emergency department of a tertiary care hospital with dyspnea as a chief complaint. The diagnosis of acute destabilized HF was based on the Framingham score for HF plus echocardiographic evidence of systolic or diastolic dysfunction. A commercially available immunoluminometric assay was used for measurement of MR-proANP plasma concentrations. RESULTS: Median MR-proANP plasma concentrations were significantly higher in patients with dyspnea attributable to acute destabilized HF (338 pmol/L; n = 137) than in patients with dyspnea attributable to other reasons (98 pmol/L; n = 114; P <0.001). The area under the curve for MR-proANP was 0.876 (SE = 0.022; 95% confidence interval, 0.829-0.914), and the cutoff concentration with the highest diagnostic accuracy was 169 pmol/L (sensitivity, 89%; specificity, 76%; diagnostic accuracy, 83%). In the setting evaluated, diagnostic information obtained by MR-proANP measurements was similar to that obtained with B-type natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) measurements. CONCLUSIONS: MR-proANP measurements may be useful as an aid in the diagnosis of acute destabilized HF in short-of-breath patients presenting to an emergency department. The diagnostic value of MR-proANP appears to be comparable to that of BNP and NT-proBNP.