Tissue factor and platelet glycoprotein Ib-α alleles are associated with age at first coronary bypass operation

Background: Age is a known risk factor for postoperative complications, but the genetic factors that account for variability in age at presentation for surgery have not been characterized. Because thrombosis is a critical process in the development of coronary syndromes, the authors hypothesized that patients bearing the -1208 insertion allele of tissue factor (TF) and longer glycoprotein Ib-alpha (GpIbalpha) variants may come to surgical attention sooner and undergo coronary artery bypass grafting (CABG) at a younger age. The authors tested this hypothesis in a cardiac surgery population. Methods. The impact of the number of TF -1208 insertion alleles and the number of GpIbalpha repeats on age at first CABG were tested in 424 elective coronary bypass patients. Multivariate regression included traditional risk factors of sex, hypertension, diabetes, hyperlipidemia, and smoking. The authors also tested the hypothesis that these alleles are correlated with age at first noncoronary cardiac surgery in a group of 143 patients undergoing noncoronary cardiac operations. Results. Both the number of TF -1208 insertion alleles and total number of GpIbalpha repeats were associated with younger age at first CABG in a univariate analysis. In multivariate regression in which traditional risk factors were included, the number of TF -1208 insertion alleles and the total number of GpIbalpha repeats were independent contributors toward age at first CABG. Neither polymorphism had a significant impact on age at first noncoronary cardiac surgery. Conclusions. Genetic variants in TT and GpIbalpha are associated with younger age at first CABG, indicating that the younger and older first-time CABG populations are different on the genetic level. How these genetic differences may account for age-associated differences in perioperative risk will be the subject of future investigations.