Prediction of the excessive perioperative bleeding in patients undergoing coronary artery bypass grafting: Role of aspirin and platelet glycoprotein IIIa polymorphism

Objective

The presence of the glycoprotein IIIa allele Pl^A2 is associated with enhanced thrombin formation and an impaired antithrombotic action of aspirin, which could favor coronary thrombosis. We wondered whether Pl^A1/A2 genetic polymorphism could affect the postoperative bleeding in patients undergoing coronary artery bypass grafting. We also aimed to assess the effects of aspirin pretreatment and to ascertain the value of platelet function studies as predictors of postoperative bleeding.

Methods

In a randomized, double-blind study, patients undergoing coronary artery bypass grafting were pretreated with a 150-mg dose of aspirin orally 12 and 3 hours before surgery (n = 51, 41 elective) or with placebo (n = 51, 43 elective). The hemostasis was monitored by Simplate (bioMérieux, Inc, Durham, NC) bleeding time and capillary closure time (platelet function analyzer PFA 100; Sysmex UK Ltd, Milton Keynes, United Kingdom). Postoperative bleeding and blood products transfusions were recorded. The glycoprotein IIIa polymorphism was analyzed.

Results

Bleeding was significantly greater in Pl^A1 homozygotes from control group. Blood loss was significantly greater (by 25%) in aspirin group. The volume of blood products transfusions in aspirin patients was significantly larger (by 137%). When subjects were stratified accordingly to blood platelet glycoprotein IIb/IIIa genotype, in the aspirin group Pl^A2 carriers had greater blood loss than Pl^A1 homozygotes (1858 ± 932 mL vs 1216 ± 525 mL, P < .05).

Conclusion

Pl^A1 homozygotes normally had a greater risk of perioperative bleeding. Capillary closure time had no advantage relative to Simplate bleeding time in predicting postoperative blood loss. Aspirin pretreatment revealed no beneficial effects and resulted in increased postoperative bleeding and requirement for blood product transfusions after coronary artery bypass grafting in patients with stable angina. It was most unfavorable for Pl^A2 carriers.