Midregional pro-atrial natriuretic peptide is a useful indicator for the detection of impaired left ventricular function in patients with coronary artery disease

Aims We compared the diagnostic performance of N-terminal pro-brain natriuretic peptide (NT-proBNP) with a newly developed assay for the midregional part of pro-atrial natriuretic peptide (MR-proANP) concerning the detection of impaired left ventricular ejection function (LVEF) among patients with coronary artery disease (CAD). Methods and results Plasma levels of MR-proANP and NT-proBNP were determined in 102 consecutive patients with a history of ST-elevation myocardial infarction. Plasma levels of both markers were measured during a mean follow-up period of 687 days after acute myocardial infarction. Univariate analyses revealed inverse correlations between MR-proANP levels and LVEF (r = − 0.39; p < 0.001), NT-proBNP levels and LVEF (r = − 0.39; p < 0.001) and a positive correlation between MR-proANP and NT-proBNP (r = 0.75; p < 0.001). After adjustment for traditional risk factors, MR-proANP was the strongest predictor for LVEF (p = 0.001) in multivariate analysis, being even superior to NT-proBNP. The area under the ROC curve (AUC) indicated moderate performance (AUC = 0.73; p < 0.01) of MR-proANP regarding the detection of a reduced LVEF < 50%. The AUC of NT-proBNP for detection of impaired LVEF < 50% was 0.68 (p = 0.019). The negative predictive values of both markers were 86% for MR-proANP at a cut-off > 135 pmol/L and NT-proBNP at a cut-off > 560 pmol/L. At these cut-offs, the specificity of MR-proANP was 90%, and the specificity of NT-proBNP was 84%. Conclusions MR-proANP is a useful indicator for the exclusion of a preserved left ventricular function in patients with coronary artery disease. The study demonstrates that the diagnostic performance of MR-proANP is comparable to the “gold standard” NT-proBNP.