Tranexamic acid effects on postoperative bleeding in cardiopulmonary bypass surgery according to the plasminogen activator inhibitor-1 polymorphism

Introduction

The objective was to determine the effects of tranexamic acid (TA) on postoperative bleeding in cardiopulmonary bypass (CPB) surgery according to the 4G/5G plasminogen activator inhibitor-1 (PAI-1) gene polymorphism, the main endogenous regulator of fibrinolysis.

Methods

We performed a prospective analysis on the postoperative bleeding effect of TA prophylaxis (2 g), administered before and after CPB, according to the PAI-1 polymorphism. We recorded data related to coagulation, fibrinolysis and bleeding, preoperatively, at admission (0 hours) to the ICU, and 4 hours and 24 hours postoperatively. SPSS version 15 was used.

Results

We studied 50 patients (24 with TA and 26 without TA). In patients not receiving TA, significant differences were found between PAI-1 genotype groups (4G/4G; 4G/5G; 5G/5G) in chest-tube blood loss at 0 hours (P = 0.03), at 4 hours (P = 0.001) and at 24 hours (P = 0.009). Fresh frozen plasma was required during the ICU stay in 50% of 5G/5G, 25% of 4G/5G and none of the 4G/4G carriers (P = 0.021). 4G/4G patients did not show significant differences in blood loss between the TA and placebo groups. 4G/5G patients receiving TA had lower blood loss than the placebo group at 0 hours (P = 0.012) and at 24 hours after surgery (P = 0.014). In contrast, 5G/5G patients receiving TA had significantly lower blood loss compared with the placebo group at 0 hours (P = 0.028), at 4 hours (P = 0.008) and at 24 hours (P = 0.004) after surgery. Fifty-five percent of 5G/G patients in the placebo group received fresh frozen plasma during the ICU stay compared with no patients in the TA group (P = 0.014).

Conclusion

PAI-1 5G/5G homozygotes who did not receive TA showed significantly greater postoperative bleeding than patients with other PAI-1 genotypes. The 5G/5G homozygotes who received TA showed the greatest blood-sparing benefit.