Antithrombotic effects of aspirin based on PLA1/A2 glycoprotein IIIa polymorphism in patients with coronary artery disease.

Objective: The diallelic glycoprotein IIIa polymorphism P1A1/A2 was attributed to be an inherited risk factor for coronary events. Whether this polymorphism affects response to aspirin in patients with coronary artery disease is not known.

Methods: We assessed thrombin generation (prothrombin fragment F1+2) in consecutive blood samples collected from bleeding-time wounds in 28 men with coronary artery disease; P1A2 carriers, n=9; P1A1/A1, n=19. Thrombin generation and bleeding time were measured before and after 2 weeks of aspirin 300 mg/day.

Results: Aspirin-depressed thrombin generation in A1 homozygotes (p=0.04), but not in A2 carriers. Bleeding time after aspirin was also prolonged in A1 subjects only (p=0.02).

Conclusion: Genotyping for glycoprotein IIIa polymorphism might be helpful in predicting antithrombotic action of aspirin in secondary prevention of coronary artery disease.