Abstract 2657: A Comparative Study of Inflammatory Markers and Others Biomarkers for Risk Prediction in Acute Coronary Syndrome - The SIESTA (Systemic Inflammation Evaluation in non-ST-elevation Acute coronary syndrome) Study
We sought to compare prognostic role of several inflammatory and non-inflammatory biomarkers in Mediterranean patients admitted to hospital with Unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI). SIESTA is a multicentre prospective cohort study in patients hospitalized with UA/NSTEMI from April-2002 to June-2004. The following biomarkers were assessed at hospital admission: hs-CRP, white blood cell count, interleukins 6, 10 and 18, CD 40 ligand, P- and E- selectin, NT-proBNP, fibrinogen and cystatin C. The study composite end point included all-cause death, cardiac death, non-fatal MI, UA, percutaneous coronary intervention and coronary artery by-pass graft at one year of follow-up. Secondary end point included cardiac death, death of any cause and new MI. We used multivariable regresion logistic model to examine the association among biomarker levels and study endpoints. C statistic was used to assess the ability of individual biomarkers to classify patient risk, and for comparisons with predictive value of clinical variables alone. 610 patients (73 % male) were recruited in 26 hospitals; 217 (36%) had UA and 393 (64%) NSTEMI. 549 patients completed the 1-year follow up (90%), of whom 206 (37.5%) reached primary study endpoint and 54 (8.9%) the harder secondary endpoint . On univariate analysis, cystatin C (p < 0.01) and NT-proBNP (p = 0.05) were associated with the primary endpoint, and NT pro BNP (p=0.03) and fibrinogen (p=0.02) were significantly associated with secondary end point. The AUC for the basal model (primary end point) was 0.68 (95 % CI 0.63– 0.73), the addition of cystatin C yielded an AUC of 0.70 (95 % CI 0.65– 0.75 p=0.09). The addition of NT- proBNP either alone or together with all other biomarkers did not improve prognostic. With regard to the secondary study endpoint the C-statistics analysis showed that NT pro BNP and fibrinogen modestly increased the AUC (3.1–5.5 % respectively p < 0.05). The combination of both significantly improved AUC (0.70 vs 0.78, p=0.03). Our study showed that assessment of several biomarkers, including hs-CRP, offers modest additional information to that afforded by conventional markers of risk in Mediterranean patients with UA/NSTEMI.