Cardiac surgical procedures account for a large amount of allogeneic transfusion. Tranexamic acid (TA), a synthetic antifibrinolytic drug, has been shown to reduce blood loss and transfusion requirements in cardiac surgery with Cardiopulmonary bypass. There are currently multiple dosing regimens for TA in cardiac surgery. Preliminary dose-response study has shown that low dose of TA would be as hemostatic efficacy as higher dose. Currently, no randomized study focus on TA in primary valve surgery. The aim of this prospective, double-blinded, randomized trial is to compare two dosing regimens of TA during primary valve surgery on perioperative blood loss and allogeneic blood transfusion.

Inclusion Criteria:

• valvular disease patients requiring valvular replacement or repair surgery with cardiopulmonary bypass (CPB)

Exclusion Criteria:

• a history of bleeding disorders
• active chronic hepatitis or cirrhosis
• chronic renal insufficiency (serum creatinine > 2 mg/dl)
• preoperative anemia (Hb < 10 g/dl)
• previous cardiac surgery
• urgent and emergency surgery