A multi-marker approach for the prediction of adverse events in patients with acute coronary syndromes

Background: Cardiac troponin T (cTnT), high sensitivity C-reactive protein (hs-CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) have emerged as strong predictors of adverse events among patients presenting with acute coronary syndromes (ACS). We evaluated the prognostic performance of each of these markers, individually, and in combination in patients presenting to the emergency department (ED) with ACS symptoms. Methods: Serum samples were obtained from 422 consenting patients presenting to the ED with symptoms of acute coronary syndrome (ACS) and subsequently tested for cTnT, NT-proBNP, myoglobin, CK-MB, and hs-CRP. Adverse events (AEs) occurring within 30 days (death, myocardial infarction, unstable angina and the need for revascularization procedures) were recorded and ROC curves were constructed. Results: AEs occurred in 42 patients (10%). Relative risk, cut-off, and predictive values for each biomarker were determined statistically, with the exception of cTnT, where the concentration meeting the 99th percentile of a healthy population with a 10% coefficient of variation (0.03 ng/ml) was used. These cut-off values, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and relative risk (RR) were calculated. Sensitivity and RR for a panel of cTnT and NT-proBNP were 78.6% (66.2-91.0) and 4.7 (2.3-9.5), respectively. Conclusions: If used alone, cTnT appeared to have greater prognostic value when compared to hs-CRP, NT-proBNP, myoglobin or CK-MB. The combination of cTnT and NT-proBNP performed better than the combination of cTnT and hs-CRP. When cTnT, NT-proBNP and hs-CRP were used as a panel, there was no significant improvement in prognostic performance over using cTnT and NT-proBNP together. Thus, in patients with suspected ACS, the measurement of both cTnT and NT-proBNP may have enhanced prognostic performance over using either marker in isolation.