In a meta-analysis of data from 805 patients,1100 doses of preoperative aspirin 325 mg were associated with increased bleeding (mean difference, 230 mL), whereas those who received 325 mg preoperatively did not have a significant increase in blood loss (mean difference: 65.3 mL; 95% CI: 20.2 to 150.8; P 0.134). Some subjects undergoing CABG are receiving DAPT. Multiple studies have shown that the preoperative use of aspirin and clopidogrel is associated with increased periop- erative bleeding, transfusions, and required reexploration for bleeding.522 524,531,1058 1062,1101 1107 In a study of 350 CABG patients at 14 centers, the risk of reexploration for bleeding was increased 3-fold in patients who were exposed to clopidogrel within 5 days of surgery; half of these patients required transfusions.520 In patients taking clopidogrel in whom elective CABG is planned, the drug should be withheld Hillis et al 2011 ACCF/AHA CABG Guideline e693 for 5 to 7 days before surgery. In subjects taking DAPT because of previous placement of a DES, clopidogrel can be stopped 1 year after the most recent DES placement. If CABG cannot be postponed, some operators have suggested that the patient be hospitalized for conversion of thienopyri- dine therapy to short-acting glycoprotein IIb/IIIa inhibitors for several days before surgery497,1063,1108,1109; however, no data are available demonstrating the efficacy of such a management strategy. Streptokinase, urokinase, and tissue- type plasminogen activator should be stopped before CABG; in these individuals, the timing of CABG depends on the pharmacodynamic half-life of the agent involved.1110 The use of unfractionated heparin has not been associated with increased perioperative blood loss; it can be continued until a few hours before CABG. 