Blood conservation outcomes and safety of tranexamic acid in coronary artery bypass graft surgery

Background: The safety and blood management effects of Tranexamic acid (TXA) and its dose effects in coronary artery bypass graft (CABG) were still ambiguous. This study aimed to analyze these TXA effects. Methods: Overall, 42,010 patients undergoing CABG were enrolled in this retrospective cohort study. Patients were assigned to the TXA group (n = 29,536) and the no-TXA group (n = 12,474). Furthermore, the TXA group was divided into the high-dose (>= 50 mg/kg) (16,488) and the low-dose (<50 mg/kg) (13,048) subgroup. Propensity score matching was performed in both groups respectively. The primary endpoint after CABG was composed of hospital death, perioperative myocardial infarction (PMI), stroke, acute kidney injury (AKI), and pulmonary embolism. The secondary endpoint included blood loss and blood transfusion after surgery. Results: TXA led to a 1.40-fold risk of PMI (p < 0.001). Patients in the TXA group had fewer re-operations for bleeding or tamponade [Odd ratio (OR) = 0.82, p = 0.044], less blood loss after surgery (p < 0.001), and a lower risk for blood transfusion exposure (OR = 0.45, p < 0.001) than those in the no-TXA group. The high-dose TXA reduced blood loss after cardiac surgery compared to the low-dose TXA (p < 0.001) with no associations with blood exposure or adverse events. Conclusions: The use of TXA during CABG increased the risk of PMI despite better blood control after surgery. The high dose of TXA acquired better bleeding management. Meanwhile, it did not increase the risk of primary endpoint.