CYP2C19 Genotypes and Stent Thrombosis: Is There a Correlation?

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 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.