Protective Effects of Tranexamic Acid on Clopidogrel Before Coronary Artery Bypass Grafting

Results: As compared with controls, clopidogrel increased blood loss (mean difference [MD], 270 mL; 95% CI, 135 to 404 mL), major bleeding (risk difference [RD], 18.5; 95% CI, 7.85 to 29.2), volume of RBCs transfused (MD, 2.97 U; 95% CI, 1.51 to 4.43 U), and RBC transfusion exposure (RD, 17.9; 95% CI, 8.51 to 27.2). As compared with placebo, tranexamic acid reduced blood loss (MD, 278 mL; 95% CI, 380 mL to 176 mL), major bleeding (RD, 19.5; 95% CI, 27.7 to 11.4), volume of RBCs transfused (MD, 2.58 U; 95% CI 3.61 U to 1.55 U), and RBC transfusion exposure (RD, 18.9; 95% CI, 26.4 to 11.4). Subgroup analysis demonstrated a significantly enhanced effect of tranexamic acid especially in patients with impaired platelet function. Conclusions and Relevance: Preoperative clopidogrelexposureincreasedbleedingandtransfusionrequirements in patients receiving on-pump CABG. Tranexamicacidreducedthisriskandprovidedextraprotection selectively in the patients with persistent clopidogrel exposure within 7 days before surgery. Trial Registration: clinicaltrials.gov Identifier: NCT01060163.