Impact of CYP3A5 polymorphism on platelet reactivity at percutaneous coronary intervention and after 9 months of aspirin and clopidogrel therapy in Japanese patients with coronary artery disease

Cyp2C19*2 Polymorphism Related to Clopidogrel Resistance in Patients With Coronary Heart Disease, Especially in the Asian Population: A Systematic Review and Meta-Analysis

In recent years, the relationship between Cyp2C19*2 gene polymorphism and clopidogrel resistance reflected by platelet function assay has been studied extensively, but there is no clear conclusion yet. In order to evaluate the relationship between Cyp2C19*2 gene polymorphism and clopidogrel resistance more accurately, meta-analysis was conducted in this study. The I² value taking 50% as the limit, the heterogeneity is judged as high or low, and then a random effect model or a fixed effect model is selected for statistical analysis. PubMed, EMBASE, Web of Science, CNKI, and China Wanfang database were searched, and the related literatures from the establishment of the database to May 2020 were collected and analyzed by STATA 15.0 software. A total of 3,073 patients were involved in 12 studies, including 1,174 patients with clopidogrel resistance and 1,899 patients with non-clopidogrel resistance. The results of this study showed that allele model (A vs. G): OR = 2.42 (95%CI: 1.97-2.98); dominant model (AA+GA vs. GG): OR = 2.74 (95%CI: 2.09-3.59); recessive model (AA vs. GA+GG): OR = 4.07 (95%CI: 3.06-5.41); homozygous model (AA vs. GG): OR = 5.70 (95%CI: 4.22-7.71); heterozygote model (GA vs. GG): OR = 2.32 (95%CI: 1.76-3.07), the differences were statistically significant. Also, the analysis of the Ethnicity subgroup indicated that the Asian allele model and the other four gene models were statistically significant. In conclusion, Cyp2C19*2 gene polymorphism is strongly associated with clopidogrel resistance. Allele A, genotype GA, AA, and GG + GA can increase clopidogrel resistance, especially in the Asian population.

High interindividual variability in plasma clopidogrel active metabolite concentrations in healthy cats is associated with sex and cytochrome P450 2C genetic polymorphism

Clopidogrel response variability has been identified in cats. In humans, evidence suggests that variable clopidogrel active metabolite (CAM) generation is the primary explanation for clopidogrel response variability with differences in body weight, sex, and variable metabolism of clopidogrel primarily due to polymorphisms of the gene encoding cytochrome P450 (CYP) 2C19 as some proposed mechanisms. The aim of this study was to evaluate whether variation in CAM concentrations exists in healthy cats and what the cause of such variation might be. Nineteen healthy cats were given 18.75 mg clopidogrel by mouth. Blood was collected 2 hr later. Plasma CAM concentrations were measured using high performance liquid chromatography and tandem mass spectrometry. Clopidogrel metabolism was estimated by calculating CAM metabolic ratio. DNA was collected, and feline CYP2C genotyping was performed. The cats demonstrated high interindividual variation of plasma CAM concentrations. Approximately 69% of this interindividual variation was primarily explained by differences in clopidogrel metabolism as measured by CAM metabolic ratio with some influence by sex but not by weight. A single nucleotide polymorphism was identified in the feline CYP2C gene that explained in part individual differences in CAM metabolic ratio and CAM plasma concentrations.

Pharmacokinetic and Pharmacodynamic Responses to Clopidogrel: Evidences and Perspectives

Clopidogrel has significantly reduced the incidence of recurrent atherothrombotic events in patients with acute coronary syndrome (ACS) and in those undergoing percutaneous coronary intervention (PCI). However, recurrence events still remain, which may be partly due to inadequate platelet inhibition by standard clopidogrel therapy. Genetic polymorphisms involved in clopidogrel’s absorption, metabolism, and the P2Y12 receptor may interfere with its antiplatelet activity. Recent evidence indicated that epigenetic modification may also affect clopidogrel response. In addition, non-genetic factors such as demographics, disease complications, and drug-drug interactions can impair the antiplatelet effect of clopidogrel. The identification of factors contributing to the variation in clopidogrel response is needed to improve platelet inhibition and to reduce risk for cardiovascular events. This review encompasses the most recent updates on factors influencing pharmacokinetic and pharmacodynamic responses to clopidogrel.

Patients with both CYP2C19 loss-of-function allele and peripheral endothelial dysfunction are significantly correlated with adverse cardiovascular events following coronary stent implantation

BACKGROUND

There is some controversy regarding the effect of CYP2C19 polymorphism on clinical outcome in patients receiving dual antiplatelet therapy (DAPT). Peripheral endothelial dysfunction has recently been reported to predict adverse cardiovascular events. We hypothesized that CYP2C19 loss-of-function (LOF) allele carriers with peripheral endothelial dysfunction had worse prognosis. The aim of this study was to evaluate an additive effect of peripheral endothelial dysfunction on clinical outcome following percutaneous coronary intervention (PCI) in patients with a CYP2C19 variant.

METHODS

We enrolled 434 patients on DAPT following PCI. CYP2C19 genotype was examined, and we divided patients into two groups: carriers, who had at least one CYP2C19 LOF allele, and non-carriers. Peripheral endothelial dysfunction was examined using reactive hyperemia-peripheral arterial tonometry index (RHI), and we divided patients into low and high RHI. Thus, subjects were divided into four groups, and clinical events were followed up.

RESULTS

A total of 55 patients had a cardiovascular event. Kaplan-Meier analysis demonstrated a significantly higher probability of cardiovascular events in carriers with low RHI (log-rank test: p=0.007). Multivariate Cox proportional hazards analysis identified both CYP2C19 LOF allele possession (hazard ratio (HR): 1.94; 95% confidence interval (CI): 1.1-3.69; p=0.045) and low RHI (HR: 2.15; 95% CI: 1.22-3.78; p=0.008) as independent and significant predictors of future cardiovascular events.

CONCLUSIONS

CYP2C19 LOF allele carriers with peripheral endothelial dysfunction were significantly correlated with cardiovascular events. The additional evaluation of peripheral endothelial function along with CYP2C19 polymorphism might improve risk stratification after coronary stent implantation.