Prophylactic tranexamic acid in elective, primary coronary artery bypass surgery using cardiopulmonary bypass

Abstract

Objective: Perioperative use of tranexamic acid (TA), a synthetic antifibrinolytic drug, decreases perioperative blood loss, and the proportion of patients receiving blood transfusion in cardiac surgery, but the results may vary in different clinical settings. The primary objective of the present study was to determine the efficacy of TA to decrease chest tube drainage and the proportion of patients requiring perioperative allogeneic transfusions following primary, elective, on-pump coronary artery bypass grafting (CABG) in patients with a low baseline risk of postoperative bleeding.

Methods: In a double-blinded, prospective, placebo-controlled study, 46 patients were randomized into two groups. One group received TA 1.5 g as a bolus, followed by a constant infusion of 200 mg/h until 1.5 g. The other group received placebo (0.9% saline). Among exclusion criteria were treatment with acetylsalicylic acid, non-steroidal anti-inflammatory drugs or other platelet inhibitors within 7 days before surgery.

Results: Preoperative demographics, biochemical and surgical characteristics were comparable between groups. At 6 h postoperatively, there was a trend towards a greater blood loss (median and interquartile range) in the placebo group (710 and 460-950 ml) compared to the TA group (400 and 350-550 ml), but the difference did not reach statistical significance. Neither were transfusion rates and the amount of autotransfused shed mediastinal blood different between the groups postoperatively. Postoperative d-dimer concentrations were significantly higher in the placebo group compared to the TA group (P < 0.001) This difference could not be explained by differences in the amount of autotransfused shed mediastinal blood alone. Plasma concentrations of beta-thromboglobulin and platelet factor 4 were significantly increased postoperatively in both groups, but without any intergroup differences. Seven patients (15%), one in the TA group and six in the placebo group, were reoperated due to excessive bleeding. Surgical correctable bleeding was found in all except two patients from the placebo group.

Conclusions: An antifibrinolytic effect following prophylactic use of TA in elective, primary CABG among patients with a low risk of postoperative bleeding, did not result in any significant decrease in postoperative bleeding compared to a placebo group.