Fibrinolysis, which commonly occurs following cardiopulmonary bypass (CPB), may be related to the excessive bleeding (EB) and morbidity after CPB. It is known that tissue factor (TF), which is triggered by CPB, plays an important role in the initiation of fibrinolysis during and after CPB, however, EB and fibrinolysis after CPB show inter-individual variance. Therefore, in this study, TF-603A/G polymorphism was evaluated to determine if it is associated with fibrinolysis and/or EB and morbidity following CPB.

RT-PCR was used to determine the TF genotype of each patient. In addition, the amount of blood loss that occurred during the first 24 hours following surgery was documented, and EB was diagnosed when more than 1 L of blood was lost during the first 24 hours following surgery. The D-dimer levels were measured at; a) Time 1; prior to initiation of CPB, b) Time 2; 2 hours after CPB, and c) Time 3; 24 hours after CPB. The oxygen index (OI) was calculated at; 1) OI1; upon admission to the ICU, b) OI2; 24 hrs after admission to the ICU, and c) OI3; 48 hrs after admission to the ICU. The intubation time and the length of the ICU stay were also documented.

The serum D-Dimer level of the TF-603AA group (n = 72) measured at time 3 was higher than that of the TF-603GG/GA group (n = 25) measured at the same time. In addition, the incidence of EB and the intubation time of the TF-603AA group were higher than those of the TF-603GG/GA group. Finally, the OI3 of the TF-603AA group was lower than that of the TF-603GG/GA group.

The G allele that is associated with TF-603A/G polymorphism may be protective against fibrinolysis following CPB, therefore, it may also be protective against EB and morbidity following CPB.