Administration of antiplatelet therapy Aspirin and Clopidogrel (CLP) is a corner stone inpatients with Acute Coronary Syndrome (ACS) undergoing Percutaneous Coronary Intervention (PCI) with/without stent implantation. The CYP2C19*2 allele is the most important genetic variant determining response to CLP. We aim to investigate frequency of CYP2C19*2 polymorphism in patients with ACS and significance for the individual response to CLP therapy. The preliminary data of a study including a total of 120 patients with ACS undergoing PCI with stent placement and treated with dual antiplatelet therapy (CLP and Aspirin) are presented. So far 18 patients (41-81 year age) are tested for CYP2C19*l/*2 polymorphisms. The genotype CYP2C19*1/*1; CYP2C19*l/*2 and CYP2C19*2/*2 is demonstrated in 50%, 33%, 17% respectively, of the patients. The established frequency of CYP2C 19*2 allele (33%) is significantly higher (x2=5.220; p=0.022) than in healthy Bulgarian individuals (16%). In-stent thrombosis have developed 3 (17%) of patients: 2 are C YP2C19* l/*2 carriers, and 1 - homozygous CYP2C19*2/*2. The preliminary data demonstrate high prevalence of CYP2C19*2 polymorphism in patients with ACS and point to significance of the variant for CLP therapy. Further extension of the study with larger samples and monitoring of the patients are required to determine the effects of the polymorphism on the prognosis for major adverse cardiovascular events.

CYP2C19 polymorphism, Clopidogrel, Acute Coronary Syndrome, in-stent thrombosis