Prospective analysis after coronary-artery bypass grafting: platelet GP IIIa polymorphism (HPA-1b/PIA2) is a risk factor for bypass occlusion, myocardial infarction, and death.

Recently, we have demonstrated that human platelet antigen 1b (HPA-1b or P1A2) is a hereditary risk factor for platelet thrombogenicity leading to premature myocardial infarction in preexisting coronary artery disease. However, HPA-lb does not represent a risk factor for coronary artery disease itself. The aim of our present study was to evaluate the role of HPA-lb on the outcome in patients after coronary-artery bypass surgery. We prospectively determined the HPA-1 genotype in 261 consecutive patients prior to saphenous-vein coronary-artery bypass grafting. The patients were followed for one year. Among patients with bypass occlusion, myocardial infarction, or death more than 30 days after surgery, the prevalence of HPA-lb was significantly higher than among patients without postoperative complications (60 percent, 6/10, vs. 24 percent, 58/241, p <0.05, odds ratio 4.7). Using a stepwise logistic regression analysis with the variables HPA-1b, age, sex, body mass index, smoking (pack-years), hypertension, diabetes, cholesterol and triglyceride concentration, only HPA-lb had a significant association with bypass occlusion, myocardial infarction, or death after bypass surgery (p = 0.019, odds ratio 4.7). This study shows that HPA-1b is a hereditary risk factor for bypass occlusion, myocardial infarction, or death in patients after coronary-artery bypass surgery.