The use of platelet aggregation inhibitors, including aspirin and clopidogrel, has become a standard management strategy for patients with acute coronary syndrome. On this background, an increasing percentage of patients presenting for surgical coronary revascularization is the subject to irreversible platelet inhibition.

Tranexamic acid is a widely used antifibrinolytic agent, and is a promising substitute for aprotinin when the latter has been suspended in 2007.The release of plasmin during CPB activates fibrinolysis and may contribute to platelet dysfunction. Pharmacological inhibition of the fibrinolytic system may therefore ameliorate platelet dysfunction and fibrinolysis after CPB and decrease postoperative bleeding. Tranexamic acid prevents plasmin formation and inhibits fibrinolysis.

Many studies and meta-analyses have shown a reduction in postoperative bleeding and transfusion requirements of this antifibrinolytic drug in cardium revascularization surgery. Unfortunately the preoperative antiplatelet therapy was either neglected or obscure. Few studies specify the time between the last clopidogrel ingestion and surgery.Several studies were keen on the blood loss and allogeneic transfusion in patients who received their last clopidogrel or asprin within 7 days prior to coronary artery bypass grafting. Concerning the secession of aprotinin and the increasing proportion of patients with persistence on clopidogrel until their surgery, evolutional work is expected, especially in the eastern population.

The purpose of this study is to assess the effect of tranexamic acid in patients with clopidogrel and asprin ingestion less than 7 days prior to surgery. The working hypothesis is that tranexamic acid would reduce bleeding and transfusion requirements in this specific population of patients.

Inclusion Criteria:

• Men and women aged 18-85 years undergoing primary and isolated on-pump CABG
• Last ingestion of clopidogrel and aspirin within 7 days preoperatively

Exclusion Criteria:

• Previous cardiac surgery
• Hematocrit <33%
• Platelet count <100,000/ml
• Allergy to tranexamic acid
• Recruited in other studies