International Journal of Research and Review Vol.7; Issue: 3; March 2020 Website: www.ijrrjournal.com Original Research Article E-ISSN: 2349-9788; P-ISSN: 2454-2237 International Journal of Research and Review (ijrrjournal.com) 218 Vol.7; Issue: 3; March 2020 CYP2C19 Genotypes and Stent Thrombosis: Is There a Correlation? P V Dattatreya 1 , Tarun Kumar 2 , Cholenahally N Manjunath 1 1 Sri Jayadeva Institute of Cardiovascular Sciences & Research, Bangalore 2 Dr Ram Manohar Lohia Hospital, Delhi Corresponding Author: Tarun Kumar ABSTRACT Background: Clopidogrel is an inactive prodrug and becomes active by undergoing enzymatic reaction. We conducted a study to investigate the impact of genetic variation in metabolism of clopidogrel in patients with angiographically proven stent thrombosis compared to control population. Methods: A total of 51 patients were included in the study between January 2011 and January 2013. Twenty six patients with angiographically proven cases of stent thrombosis were compared with matched post percutaneous coronary intervention patients treated during the same time period and had completed at least six month follow-up. Each group were evaluated in clinical parameters, investigation profile and allele specific PCR (AS-PCR) analysis (CYP2C19) of clopidogrel metabolism. Patients were classified as normal, intermediate or poor metabolisers from the for allele specific PCR analysis. Both the groups were compared using chi square test. P value < 0.05 was considered statistically significant. Results: The mean age of the population was 56.08±8.48 and 59.28±9.16 for stent thrombosis and control group, respectively. In patients with stent thrombosis, prevalence of Intermediate metaboliser seen in 50 % (vs. 56% in control group p = 0.847), poor metaboliser seen in 42.30 % (vs. 4 % in control group, p = 0.004) and normal metaboliser seen in 7.69 % (vs. 40% in control group, p=.021). Mortality was seen only in 2 patients in stent thrombosis group having poor metaboliser genotype. Conclusion: This data provide a little insight into the role of genetic testing for planning treatment of complex/high risk PCI. From the data, it can be concluded that stent thrombosis was more frequently associated with poor clopidogrel metaboliser’s subgroup. Key words: clopidogrel resistance; CYP2C19; PCI; stent thrombosis INTRODUCTION Dual-antiplatelet therapy (DAPT)is proven to be effective in preventing stent thrombosis to a greater extent. It is considered as standard of care in patients who underwent percutaneous coronary intervention (PCI). Despite the administration of DAPT, ST reported at a rate of 0.5-2% in elective cases and up to 6% in acute coronary syndromes(ACS) patients. [1,2] Mechanism involving poor clopidogrel response is not clearly understood. Clopidogrel is an inactive pro- drug and CYP2C19 is one of the major enzymes involved in its metabolism. Thus, cellular or genetic factors are considered as responsible for poor metabolism of clopidogrel. [3] Functional polymorphisms in the CYP2C19gene result in highly variable enzyme activity. [4] Clopidogrel non- responsiveness is reported to vary between 4% to 44% among different populations. [5] Carriers of the CYP2C19*2 reduced function allele have significant reductions in platelet inhibition [6] and increased risk of adverse cardiovascular events with 3-fold increase in ST. [7] The aim of this study was to investigate the impact of genetic variation in metabolism of clopidogrel in patients with angiographically proven stent