Outcomes following pre-operative clopidogrel administration in patients with acute coronary syndromes undergoing coronary artery bypass surgery: the ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial

Abstract

Objectives: This study sought to evaluate the impact of upstream clopidogrel in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) requiring coronary artery bypass grafting (CABG) from the ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial.

Background: Despite benefits of clopidogrel in patients with NSTE-ACS undergoing percutaneous coronary intervention, this agent is often not administered upstream (before angiography) as recommended by the American College of Cardiology/American Heart Association guidelines because of potential bleeding in the minority of patients who require CABG.

Methods: The ACUITY trial enrolled 13,819 patients with NSTE-ACS undergoing early invasive management. The timing of clopidogrel initiation was per investigator discretion. A 5-day washout period before CABG was recommended for patients having received clopidogrel.

Results: Of 13,819 patients enrolled, 1,539 (11.1%) underwent CABG before discharge. Clopidogrel-exposed patients had a longer median duration of hospitalization (12.0 days vs. 8.9 days, p < 0.0001), but fewer adverse composite ischemic events (death, myocardial infarction, or unplanned revascularization) at 30 days; 12.7% vs. 17.3%, p = 0.01), with nonsignificantly different rates of non-CABG-related major bleeding (3.4% vs. 3.2%, p = 0.87) and post-CABG major bleeding (50.3% vs. 50.9%, p = 0.83) compared with those patients not administered clopidogrel. By multivariable analysis, clopidogrel use before CABG was an independent predictor of reduced 30-day composite ischemia (odds ratio: 0.67, 95% confidence interval: 0.48 to 0.92, p = 0.001) but not of increased post-CABG major bleeding (odds ratio: 0.98, 95% confidence interval: 0.80 to 1.19, p = 0.80).

Conclusions: Clopidogrel administration before catheterization in patients with NSTE-ACS requiring CABG is associated with significantly fewer 30-day adverse ischemic events without significantly increasing major bleeding, compared to withholding clopidogrel until after angiography. These findings support the American College of Cardiology/American Heart Association guidelines for upstream clopidogrel administration in all NSTE-ACS patients, including those who subsequently undergo CABG. (Comparison of Angiomax Versus Heparin in Acute Coronary Syndromes [ACS]; NCT00093158).