N-terminal pro–brain natriuretic peptide for additional risk stratification in patients with non–ST-elevation acute coronary syndrome and an elevated troponin T: An Invasive versus Conservative Treatment in Unstable coronary Syndromes (ICTUS) substudy

Abstract

New evidence has emerged that the assessment of multiple biomarkers such as cardiac troponin T (cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with non-ST-elevation acute coronary syndrome (nSTE-ACS) provides unique prognostic information. The purpose of this study was to assess the association between baseline NT-proBNP levels and outcome in patients who have nSTE-ACS with an elevated cTnT and to determine whether patients with elevated NT-proBNP levels benefit from an early invasive treatment strategy. Baseline samples for NT-proBNP measurements were available in 1141 patients who have nSTE-ACS with an elevated cTnT randomized to an early or a selective invasive strategy. Patients were followed-up for the occurrence of death, myocardial infarction (MI), and rehospitalization for angina. We showed that increased levels of NT-proBNP were associated with several indicators of risk and severe coronary artery disease. Mortality by 1 year was 7.3% in the highest quartile (> or = 1170 ng/L for men, > or = 2150 ng/L for women) compared with 1.1% of patients in the lower 3 quartiles (P < .0001). N-terminal pro-brain natriuretic peptide (highest quartile vs lower 3 quartiles) was a strong independent predictor of mortality (hazard ratio 5.0, 95% CI 2.1-11.6, P = .0002). However, NT-proBNP levels were not associated with the incidence of recurrent MI by 1 year. Furthermore, we could not demonstrate a benefit of an early invasive strategy compared with a selective invasive strategy in patients with an elevated NT-proBNP level. We confirmed that NT-proBNP is a strong independent predictor of mortality by 1 year but not of recurrent MI in patients who have nSTE-ACS with an elevated cTnT. We could not demonstrate a benefit of an early invasive strategy compared with a selective invasive strategy.