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. Graft patency was assessed with computed tomography angi- ography, which was performed for 79 patients at 1 month. No difference was seen in terms of graft patency between the 2 groups, either among all grafts (92.9% versus 95%, aspirin versus aspirin and clopidogrel; P=0.43) or vein grafts alone (93.2% versus 93.5%, aspirin versus aspirin and clopidogrel; P=0.92). In the first trial to demonstrate a statistical impact of clopi- dogrel on graft patency, Gao et al41 randomized 249 patients undergoing CABG (58% off-pump) to receive either clopi- dogrel 75 mg plus aspirin 100 mg daily or aspirin 100 mg alone starting within 48 hours of surgery. No blinding or pla- cebo control was used in this trial. At 3 months, graft patency was assessed in 90% of patients with computed tomography angiography. Overall graft patency was not significantly dif- ferent between the 2 groups (89.7% versus 93.5%, aspirin versus aspirin and clopidogrel; P=0.07). However, vein graft patency was significantly improved in the combined treatment group compared with the isolated aspirin treatment group (85.7% versus 91.6%, aspirin versus aspirin and clopidogrel; P=0.04). 