The effectiveness of low dose tranexamic acid in primary cardiac surgery

This randomized controlled clinical trial compared three doses of tranexamic acid (TA) in primary cardiac surgery in terms of blood loss and transfusion requirements.

Patients presenting for primary coronary artery bypass grafting (CABG) and/or valve replacement were randomly assigned to one of three TA regimens: 20 mg.kg-1 (LD), 50 mg.kg-1 (MD), and 100 mg.kg-1 (HD). All participants and staff were blinded to the allocation. Haemoglobin (Hgb), haematocrit and platelet count were determined preoperatively, after bypass, at CCA arrival, and 12 and 24 hr after surgery. Coagulation parameters were measured before and after surgery. Blood loss was measured intraoperatively and for 24 hr postoperatively following a standardized protocol. Blood products were administered in a standardized fashion.

Two hundred twenty patients completed the trial over 10 months: 74 in LD, 75 in MD and 72 in HD dose groups. All patients groups were comparable; similar procedures were performed in each group. No differences were identified for blood loss intra-operatively (490 +/- 232 ml, 523 +/- 413 ml, 488 +/- 357 ml, respectively), 24 hr post-operatively (543 +/- 223 ml, 544 +/- 231, 458 +/- 210 ml, respectively), and overall (1032 +/- 358 ml, 1067 +/- 502 ml, 946 +/- 459 ml, respectively). Blood product administration was similar in the three groups. No differences in postoperative complications were found.

This study demonstrates the equivalency of the three doses of TA in primary cardiac surgical procedures. The use of low dose (20 mg.kg-1) TA results in comparable outcomes, without additional complications.