Objective: B-type natriuretic peptide (BNP) has been employed as a risk marker in patients with coronary artery disease (CAD) with ST elevation and non-ST elevation. It is not yet established if early BNP measurements provide additional information to troponin and electrocardiographic analysis in patients without ventricular enlargement and systolic dysfunction.
Design: This study compared BNP levels in patients with stable angina (SA) and acute coronary syndromes with non-ST elevation in relation to angiographic lesions (NSTEMI-ACS). Moreover, the diagnostic utility of BNP was determined using the receiver operating characteristic curve.
Patients: 280 patients with CAD without ST elevation and preserved systolic function were studied. BNP samples were measured in all recruited patients within 24 hours of hospitalization.
Results: BNP values increased progressively with the severity of diagnosis: SA (n = 85; 50.4 ± 50 pg/ml) NSTEMI-ACS (n = 195; 283 ± 269 pg/ml; p < 0.0001). The analysis of BNP in relation to the number of involved vessels demonstrated significantly increased levels in patients with multivessel disease compared to patients with 1- or 2-vessel disease (p < 0.001 and p < 0.003). Values of BNP >80 pg/ml were shown to be able to predict CAD severity and coronary vessel involvement (AUC = 0.80; p = 0.0001) with a sensitivity of 78% and a specificity of 72%. In multivariate analysis, BNP levels >80 pg/ml, CAD history, and ST deviation >2 mm were confirmed as independent predictors of CAD severity.
Conclusions: Circulating BNP levels appear elevated in NSTEMI-ACS, without left ventricular systolic dysfunction. A BNP cut-off value of 80 pg/ml is a good predictor of CAD extension.