Issues
Factors influencing the antiplatelet therapy in patients requiring vascular surgery
The antiplatelet agent clopidogrel (CLO) is a prodrug mainly activated by the CYP2C19. The CYP2C19-*2 and -*3 SNPs, called Loss of Function alleles, are associated to a phenotype of intermediate (IM) and poor metabolizers (PM). The CYP2C19- *17 SNP identifies the rapid and ultra-rapid metabolizers (UMs) (1). IMs and especially PMs might be not able to efficiently activate the drug and they are at greater risk of thrombotic events. ABCB1C3435T influences the impaired function of P-glycoprotein thereby hindering the CLO absorption. Patients with TT genotype have a higher rate of cardiovascular events than those with CC genotype. ABCB1C3435T SNP seems to influence ADP dependent platelet reactivity and T-allele carriers are likely to have a poor response to antiplatelet therapy (AT) (2). Proton Pump Inhibitors (PPIs), primarily omeprazole and esomeprazole, are inhibitors of CYP2C19. Actually, it has been shown that drug-drug interaction between PPIs and CLO might lead to an attenuated antiplatelet effect (3). Female gender has been associated with variable responses to AT enhancing basal platelet reactivity, resulting in high residual on-treatment platelet reactivity. In primary cardiovascular prevention, intake of aspirin would lead to a decrease in important coronary events in men, but not in women. Main aim of this study was to investigate the association between several factors influencing AT and platelet aggregation values in patients eligible for vascular surgery (VS) treated with AT.
