Abstract 2374: Comparison between a Newly Developed Immunoassay for the Mid Regional Part of Pro-Atrial Natriuretic Peptide and N-Terminal Pro-Brain Natriuretic Peptide for the Diagnosis of Impaired left Ventricular Function and the Risk for Cardiovascular Events in Patients with Coronary Heart 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 function (LVF) and analyzed the prognostic utility of both assays for future cardiovascular events.
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 positive correlations between MR-proANP levels and LVF (r=−0.40; p<0.001), NT-proBNP levels and LVF (r=−0.39; p<0.001) and between MR-proANP and NT-proBNP (r=0.75; p<0.001). After adjustment for traditional risk factors and high-sensitivity C-reactive protein (hsCRP) MR-proANP was a stronger predictor for LVF (p=0.001) in multivariate analysis, being even superior to NT-proBNP. The area under the ROC curve (AUC) indicated good predictive performance (AUC=0.73; p<0.01) of MR-proANP regarding a reduced LVF < 50%. The AUC of NT-proBNP for detection of impaired LVF < 50% was 0.68 (p=0.019). The negative predictive values of both markers were 86% for MR-proANP >135 pmol/mL and NT-proBNP >560 pmol/L. The specificity of MR-proANP at a cut-off value >135 pmol/mL was 90%, the specificity of NT-proBNP at a cut-off value >560 pmol/L was 84%. In a logistic regression approach MR-proANP showed a trend for being predictive for coronary reinterventions (p=0.07). NT-proBNP was one of the strongest indicators for patients suffering from reinfarction (p=0.04).
Conclusions: Our results suggest that the diagnostic performance of MR-proANP concerning the detection of impaired LVF in patients with CHD is even superior to NT-proBNP. Determination of MR-proANP might be helpful in identifying reduced LVF in patients with CHD.