Brain natriuretic peptide and other risk markers for outcome assessment in patients with non-ST-elevation coronary syndromes and preserved systolic function

Abstract

Several emerging cardiac markers constitute strong predictors among patients with coronary artery disease. In particular, brain natriuretic peptide (BNP), troponin T (TnT), and C-reactive protein (CRP) are related to increased risk of recurrent ischemic events and death. However, little is known about the utility of these biomarkers in combination. This study examined risk assessment in patients with coronary artery disease and preserved systolic function. We studied 208 consecutive patients (138 men, 70 women) with stable angina, unstable angina, and non-Q-wave myocardial infarction whose plasma BNP, TnT, and CRP levels were measured at hospital admission. All recruited patients underwent echocardiographic examination, and selective coronary angiography was performed. After adjusting for clinical presentation, age, gender, and common risk factors, BNP was demonstrated as a strong predictor of heart failure (6 months, odds ratio [OR] 2.03, 95% confidence interval [CI] 1.24 to 2.9, p <0.01; 12 months, OR 2.65, 95% CI 1.69 to 3.5, p <0.001) and mortality at 3, 6, and 12 months (p <0.001). BNP was also significantly related to extent of coronary artery disease and left anterior descending artery involvement (p <0.01). Patients with a BNP level >80 pg/ml in all 3 groups had a significantly poorer prognosis with increased incidence of heart failure and death. CRP was related to recurrent ischemic events (infarct or recurrent angina, OR 1.4, 95% CI 1.14 to 2.08, p <0.01) and was associated with major cardiac revascularization at 12 months (OR 1.51, 95% CI 1.29 to 1.73, p <0.001). TnT demonstrated a mild correlation with recurrent infarct or angina at 12 months (OR 1.1, 95% CI 0.96 to 1.22, p <0.05) but appeared related to multivessel coronary artery disease (OR 1.47, 95% CI 1.05 to 1.99, p <0.01). In conclusion, BNP appears to be associated with a long-term increased risk of mortality and heart failure in patients with apparently mild risk. BNP is also associated with a larger extent and greater severity of myocardial ischemia. Early BNP measurement could provide incremental information to TnT and CRP, and it may be the strongest independent predictor of cardiac outcome in subjects without left ventricular dysfunction or enlargement.