Objective

To assess the non-inferiority of topical intrapericardial tranexamic acid (TXA) versus intravenous TXA for efficacy and safety in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).

Methods

In this single-center randomized trial, 492 patients were assigned 1:1 to topical TXA (2.5 g in 50 mL saline via pericardial drain, clamp 30 min) or standard intravenous TXA. Primary endpoints: allogeneic red blood cell (RBC) transfusion rate (postoperative to discharge); 30-day composite adverse events (mortality, renal dysfunction, stroke, myocardial infarction, thromboembolism, seizures). Secondary endpoints included drainage volume, coagulation, and thromboelastography (TEG). The non-inferiority threshold was established at 10% for sensitivity.

Results

RBC transfusion rate was 35.0% (topical) vs. 27.6% (intravenous; 95%CI − 1.2% to 16.0%, P = 0.080). Composite adverse events were 9.8% vs. 15.4% (95%CI − 11.2% to 0.0%, P = 0.057). Topical TXA showed delayed coagulation initiation, lower fibrinogen, and higher 24-hour drainage (all P < 0.05). At 10% margin, efficacy non-inferiority was not confirmed, but safety non-inferiority was verified for all endpoints.

Conclusion

Topical intrapericardial TXA is non-inferior to intravenous TXA in safety but fails strict efficacy non-inferiority. Intravenous TXA remains first-line; topical TXA is a reasonable alternative for patients intolerant to systemic administration. Dose and timing optimization is needed to improve hemostasis.