Dose Effect of Tranexamic Acid on the Incidence of Deep Venous Thrombus in Cardiac Surgery

Inclusion Criteria: * Patients receiving selective cardiac surgery with cardiopulmonary bypass due to coronary, valvular or congenital heart disease * Written consent obtained Exclusion Criteria: * Allergy or contraindication to tranexamic acid * Severe renal impairment (serum creatinine \>250 μmol/l, or estimated creatinine clearance \<25 ml/min) * Thromboembolic disease including but not limited to: history of pulmonary embolism, spontaneous arterial thrombosis or familial hypercoaguability (eg. Lupus anticoagulant, protein C deficiency) * Thrombocytopenia defined as a platelet count \<100,000/ml * Coagulopathy defined as an international normalized ratio \> 1.5 prior to surgery * Currently enrolled in another perioperative interventional study * Pregnancy or lactation