Background: Studies have demonstrated that the mutant *2 and*3 allele of the CYP2C19 loss-of-function
polymorphism is associated with diminished metabolization of clopidogrel and an attenuated platelet response to
clopidogrel treatment. Since no such study has been conducted in this region, we examined CYP2C19 polymorphism
in Acute Coronary Syndrome (ACS) patients on clopidogrel treatment, and its effect on the cardiovascular outcomes.
Material and Methods: A total of 100 samples of ACS were included in this study and genotyping of CYP2C19 *2
and *3 gene polymorphisms was performed by a Polymerase chain reaction-Restriction fragment length polymorphism
(PCR-RFLP).
Results: The distribution of CYP2C19*2 allele w... More
Background: Studies have demonstrated that the mutant *2 and*3 allele of the CYP2C19 loss-of-function
polymorphism is associated with diminished metabolization of clopidogrel and an attenuated platelet response to
clopidogrel treatment. Since no such study has been conducted in this region, we examined CYP2C19 polymorphism
in Acute Coronary Syndrome (ACS) patients on clopidogrel treatment, and its effect on the cardiovascular outcomes.
Material and Methods: A total of 100 samples of ACS were included in this study and genotyping of CYP2C19 *2
and *3 gene polymorphisms was performed by a Polymerase chain reaction-Restriction fragment length polymorphism
(PCR-RFLP).
Results: The distribution of CYP2C19*2 allele wild *1/*1, Heterozygous *1/*2 and homozygous mutant *2/*2
genotypes was 56%, 34% and 10% respectively while for CYP2C19*3 wild*1/*1 and heterozygous *1/*3 genotypes
was 84% and 16% respectively. The frequency of compound heterozygotes (*2/*3) was found in 9% (9 of 100 patients).
CYP2C19 *1/*2 allele was found in 03 of 34 (8.8%) patients who had CV events followed by 2 of 10 (20%) patients with
mutant genotype CYP2C19*2 (*2/*2) on follow up. In the CYP2C19*3, 31.2% having heterozygous genotype (*1/*3) had
CV events as compared to 11.9% with *1/*1 (31% v/s 11.9% p> 0 .05). In the poor-metabolizer group (*2/*2 or *2/*3),
20.1% of patients had CV events on follow up compared to 15.6% in the extensive metabolizer group (*1/*1), whereas
in the intermediate group only 10% of patients had CV events (p>0.05).
Conclusion: We conclude that patients carrying CYP2C19 loss-of-function alleles had a higher rate of subsequent
cardiovascular events as against those with normal allele. Lack of significant events even in presence of variant alleles
justifies us to some extent to continue clopidogrel in our patients.
