Using multivariate analysis, the authors reported a lower risk of death (adjusted HR, 0.34; 95% CI, 0.20 0.61) in patients who received clopidogrel after surgery. However, clopidogrel did not significantly reduce the incidence of recur- rent MI, cardiovascular death, or the need for repeat revascu- larization in this study. To date, 4 clinical trials have evaluated the impact of clopi- dogrel on the process of vein graft disease and graft occlusion after on-pump CABG, although most studies have enrolled a mix of both on-pump and off-pump patients. In the first study published in 2009, Gao and colleagues37 performed a nonran- domized trial involving 197 CABG patients, 37% of whom underwent off-pump surgery. Patients were assigned postop- eratively to either isolated clopidogrel 75 mg daily (n=102) or clopidogrel 75 mg plus aspirin 100 mg daily (n=95) on the basis of a weekly alternating treatment scheme. The trial was neither blinded nor placebo controlled. No significant dif- ference in graft patency was seen when isolated clopidogrel treatment was compared with dual antiplatelet therapy after CABG through the use of computed tomography angiography year: 93.5% versus 96.3%, P=0.25, clopidogrel versus clopi- dogrel plus aspirin). Although no differences were noted in this trial, other studies have suggested that clopidogrel on its own may be insufficient as a sole antiplatelet agent early after CABG. Unlike aspirin, clopidogrel does not apprecia- bly inhibit platelet aggregation during the first 5 postopera- tive days after coronary surgery,38 and it is not until days 9 to 28 after CABG that the antiplatelet effects of clopidogrel (at daily doses of 75 mg) become apparent.39 In a subsequent placebo-controlled trial, Sun et al40 used partial blinding to compare the combination of postoperative clopidogrel 75 mg and aspirin 81 mg daily with aspirin 81 mg alone among 100 patients undergoing on-pump CABG. 