CONTEXT: At 30-day follow-up, patients with moderate- and high-risk acute coronary syndromes (ACS) undergoing early invasive treatment in the ACUITY trial with bivalirudin monotherapy vs heparin plus glycoprotein (GP) IIb/IIIa inhibitors had noninferior rates of adverse ischemic events with reduced rates of major bleeding. Deferred upstream use of GP IIb/IIIa inhibitors for selective administration to patients undergoing percutaneous coronary intervention (PCI) resulted in a significant reduction in major bleeding, although a small increase in composite ischemia could not be excluded. OBJECTIVE: To determine 1-year ischemic outcomes for patients in the ACUITY trial. DESIGN, SETTING, AND PATIENTS: A prospective, randomized, open-label trial with 1-year clinical follow-up at 450 academic and community-based institutions in 17 countries. A total of 13,819 patients with moderate- and high-risk ACS undergoing invasive treatment were enrolled between August 23, 2003, and December 5, 2005. INTERVENTIONS: Patients were assigned to heparin plus GP IIb/IIIa inhibitors (n = 4603), bivalirudin plus GP IIb/IIIa inhibitors (n = 4604), or bivalirudin monotherapy (n = 4612). Of these patients, 4605 were assigned to routine upstream GP IIb/IIIa administration and 4602 were deferred to selective GP IIb/IIIa inhibitor administration. MAIN OUTCOME MEASURE: Composite ischemia (death, myocardial infarction, or unplanned revascularization for ischemia) at 1 year. RESULTS: Composite ischemia at 1 year occurred in 15.4% of patients assigned to heparin plus GP IIb/IIIa inhibitors and 16.0% assigned to bivalirudin plus GP IIb/IIIa inhibitors (compared with heparin plus GP IIb/IIIa inhibitors, HR, 1.05; 95% CI, 0.95-1.16; P = .35), and 16.2% assigned to bivalirudin monotherapy (HR, 1.06; 95% CI, 0.95-1.17; P = .29). Mortality at 1 year occurred in an estimated 3.9% of patients assigned to heparin plus GP IIb/IIIa inhibitors, 3.9% assigned to bivalirudin plus GP IIb/IIIa inhibitors (HR, 0.99; 95% CI, 0.80-1.22; P = .92), and 3.8% assigned to bivalirudin monotherapy (HR, 0.96; 95% CI, 0.77-1.18; P = .67). Composite ischemia occurred in 16.3% of patients assigned to deferred use compared with 15.2% of patients assigned to upstream administration (HR, 1.08; 95% CI, 0.97-1.20; P = .15). CONCLUSIONS: At 1 year, no statistically significant difference in rates of composite ischemia or mortality among patients with moderate- and high-risk ACS undergoing invasive treatment with the 3 therapies was found. There was no statistically significant difference in the rates of composite ischemia between patients receiving routine upstream administration of GP IIb/IIIa inhibitors vs deferring their use for patients undergoing PCI. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00093158.