Objective: To assess the prognostic value of elevated troponin in patients with acute coronary syndromes (ACS) and baseline chronic renal insufficiency (CRI) and impact of different antithrombotic regimens on outcomes of these pts. Background : Elevated troponin levels are useful in establishing diagnosis and prognosis in patients with ACS. However the role of troponin elevation in patients with CRI has been disputed. Methods and Results: In the ACUITY trial, among a total of 13,819 patients with ACS, baseline CRI defined as creatinine clearance <60mL/min was present in 2179 pts (15.7%) of whom 1291 pts (59.2%) had troponin elevation. Patients with vs. without elevated troponin had significantly higher rates of 30-day mortality (4.7% vs. 1.0%, p<0.0001), MI (8.3% vs. 5.0%, P=0.003) and composite ischemia (13.6% vs. 7.9%, p<0.0001). The same was true with respect to 1-year rates of mortality (10.7% vs. 6.8%, p=0.0005), MI (13.3% vs. 7.3%, P<0.0001) and composite ischemia (25.2% vs. 20.6%, p=0.002). By multivariable analysis, troponin elevation in patients with baseline CRI was an independent predictor of mortality at 30 days (OR [95%CI] = 4.75 [2.34, 9.65], P<0.0001) and at 1 year (odds ratio [95%CI] = 1.58 [1.12, 2.23], P=0.009) as well as of MI at 1 year (OR [95%CI] = 1.54 [1.05, 2.25], P=0.02). Outcomes in patients with elevated troponin stratified by antithrombotic regimen are presented in the Table . Conclusions: In patients with ACS and CRI, troponin elevation is a marker of worse 30-day and 1-year outcomes. In high-risk pts with CRI and troponin elevation, bivalirudin monotherapy compared to heparin plus GPI resulted in significantly reduced rates of major bleeding without significant increase in 30-day and 1-year rates of composite ischemia.