CYP2C19 genotype and adverse cardiovascular outcomes after stent implantation in clopidogrel-treated Asian populations: A systematic review and meta-analysis

The effect of CYP2C19 gene polymorphism on clinical outcomes of patients with coronary artery disease (CAD) treated with clopidogrel remains controversial. Ethnicity has been proposed to influence clopidogrel response following stent implantation in CAD patients with different CYP2C19 genotypes. Furthermore, Asian populations are reported to have a relatively greater prevalence of CYP2C19 loss-of-function (LOF) alleles. We aimed to evaluate the impact of CYP2C19 gene polymorphism on clinical outcomes in Asian populations who underwent percutaneous coronary interventions (PCI) and received clopidogrel therapy. We conducted a comprehensive search in PubMed, EMBASE, and Cochrane Library from their inceptions to January 20, 2017. Studies that reported clopidogrel therapy information, clinically relevant outcomes (adverse cardiovascular events, stent thrombosis and bleeding), and CYP2C19 genotypes among Asian populations were included. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death and myocardial infarction. The safety endpoint was any kind of bleeding. We retrieved 20 studies of 15056 patients reporting 1301 cardiovascular events. The primary analysis showed at least one CYP2C19 LOF allele (*2 and/or *3) carriers were at an increased risk of MACE compared with non-carriers (10.58% vs. 6.07%, OR: 1.99, 95% CI: 1.64 to 2.42, p < .001). Stent thrombosis (ST) was also more frequent in LOF allele carriers (2.22% vs. 0.44%, OR: 4.77, 95% CI: 2.84 to 8.01, p < .001). Inversely, the risk of bleeding was lower in LOF allele carriers (OR: 0.66, 95% CI: 0.46 to 0.96, p < .001). Subgroup analysis was performed to assess differences by high (600 mg) or routine (300 mg) loading dose of clopidogrel and by different nationalities. The risk of MACE in LOF allele carriers remained significantly higher even in high loading dose group (high loading dose: OR 1.72, 95% CI: 1.37 to 2.16, and routine loading dose: OR 2.22, 95% CI: 1.68 to 2.94, p for subgroup heterogeneity = 0.16). Subgroup analysis between three nationalities of China, Korea, and Japan demonstrated that the risk of MACE among Chinese LOF allele carriers was the greatest (OR: 2.28; 95% CI:1.91 to 2.73). In conclusion, among Asian populations with CAD undergoing stent implantation, CYP2C19 LOF allele carriers are at greater risk of adverse cardiovascular events and lower risk of bleeding compared with non-carriers. Genetic testing may be helpful for clinicians to personalize antiplatelet therapy especially in Asian population.     

Meta-analysis of cytochrome P450 2C19 polymorphism and risk of adverse clinical outcomes among coronary artery disease patients of different ethnic groups treated with clopidogrel

Loss-of-function (LOF) variants of cytochrome P450 2C19 (CYP2C19) have been hypothesized to be associated with lesser degrees of platelet inhibition and increased risk for recurrent ischemic events in patients with coronary artery disease on clopidogrel therapy; however, studies from Western countries have yielded mixed results. We aimed to assess the impact of CYP2C19 LOF variants on clinical outcomes from different ethnic groups. Sixteen prospective cohort studies including 7,035 patients carrying ≥ 1 CYP2C19 LOF allele and 13,750 patients with the wild-type genotype were included in this meta-analysis. Carriers of ≥ 1 CYP2C19 LOF allele were at significantly higher risk for adverse clinical events compared to noncarriers during clopidogrel therapy (odds ratio [OR] 1.42, 95% confidence interval [CI] 1.13 to 1.78). The summary OR showed a significant association between CYP2C19 LOF variants and an increased risk of cardiac death (OR 2.18, 95% CI 1.37 to 3.47), myocardial infarction (OR 1.42, 95% CI 1.12 to 1.81), and stent thrombosis (OR 2.41, 95% CI 1.76 to 3.30). Stratified analysis by ethnicity of study population suggested higher odds of adverse clinical events in the Asian population with LOF variants of CYP2C19 (OR 1.89, 95% CI 1.32 to 2.72) compared to Western populations (OR 1.28, 95% CI 1.00 to 1.64). In conclusion, carrier status for LOF CYP2C19 is associated with an increased risk of adverse clinical events in patients with coronary artery disease on clopidogrel therapy despite differences in clinical significance according to ethnicity.     

High on-treatment platelet reactivity by ADP and increased risk of MACE in good clopidogrel metabolizers

High on-treatment platelet reactivity (HPR) by ADP, which primarily reflects the effect of thienopyridines, has been found to be an independent predictor of ischemic events in patients with acute coronary syndrome (ACS) on dual antiplatelet therapy. CYP2C19*2 is associated with HPR by ADP. The aim of our study was to evaluate if high on-clopidogrel platelet reactivity (HPR) by ADP is associated with an increased risk of major adverse coronary events (MACE) after ACS independent of CYP2C19*2 allele, i.e. whether genotyping patients for CYP2C19*2 polymorphism is sufficient to identify those to be switched to novel antiplatelets. A total of 1187 patients were included (CYP2C19 *1/*1 n?=?892; *1/*2 n?=?264; *2/*2 n?=?31); 76 MACE (CV death and non-fatal MI) were recorded in non-carriers of CYP2C19*2 (8.5%) and 39 in carriers of CYP2C19*2 (13.2%). At the landmark analysis in the first 6 months, HPR by ADP and CYP2C19*2 allele were both significantly and independently associated with MACE [HPR by ADP: HR?=?2.0 (95% CI 1.2–3.4), p?=?0.01; CYP2C19*2 allele: HR?=?2.3 (95% CI 1.3–3.9), p?=?0.003]. At the land mark analysis from 7 to 12 months, only HPR by ADP remained significantly associated with the risk of MACE [HPR by ADP: HR?=?2.7 (95% CI 1.4–5.3), p?=?0.003; CYP2C19*2: HR?=?0.8 (95% CI 0.2–1.1), p?=?ns]. CYP2C19*2 allele and HPR by ADP are both independently associated with an increased risk of MACE in the first 6 months after ACS. HPR by ADP is associated with an increased risk until 12 months of follow-up. Therefore, both phenotype and genotype are clinically relevant for the evaluation of the antiplatelet effect of clopidogrel and for the prognostic stratification of ACS patients.     

PEAR1基因多态性对冠心病患者预后的影响

目的分析血小板内皮聚集受体-1(PEAR1)基因多态性对冠心病患者临床预后的影响。方法连续纳入2016年12月至2018年12月于北京大学人民医院心血管内科行冠状动脉介入诊疗并接受阿司匹林和氯吡格雷双联抗血小板治疗的冠心病患者。检测患者PEAR1基因(rs822441、rs12041331)以及CYP2C19基因(rs4986893、rs4244285)单核苷酸多态性(SNP)。临床随访2年,主要终点是全因死亡、非致死性心肌梗死、缺血性卒中和不稳定型心绞痛(UA)导致再次住院的复合事件。在校正CYP2C19功能缺失型(LOF)等位基因及其他混杂因素后,利用Cox回归分析研究PEAR1基因多态性对冠心病患者临床预后的影响。结果共纳入411例冠心病患者,平均随访时间(737.7±0.7)d,共有22例发生主要终点事件。将年龄、总胆固醇、肌酐、左主干病变、CYP2C19 LOF等位基因携带状态作为协变量纳入多因素Cox回归分析中,结果显示PEAR1基因SNP rs822441、rs12041331与主要终点事件风险无相关性,但rs822441突变型等位基因携带者发生UA导致再次住院事件风险升高(校正HR 5.084,95%CI 1.071~24.131,P=0.041)。结论PEAR1基因SNP rs822441与冠心病患者临床预后具有相关性。     

急性冠脉综合征PCI术后患者CYP2C19*2、CYP2C19*3基因多态性与氯吡格雷抵抗及临床预后的关系

目的 探讨急性冠脉综合征经皮冠状动脉介入治疗（Percutaneous Coronary Intervention,PCI）术后患者CYP2C19*2、CYP2C19*3基因多态性与氯吡格雷抵抗及临床预后的关系。方法 入选310例急性冠脉综合征行PCI术的患者,采用生物传感器基因芯片技术检测所有患者CYP2C19*2、CYP2C19*3基因型,根据基因型分为强代谢组（未携带突变基因,681GG/636GG）,中代谢组（携带一个突变基因,681GA/636GG,681GG/636GA）,弱代谢组（携带两个突变基因,681GA/636GA,681AA/636GG,681GG/636AA）。采用全流式细胞术定义氯吡格雷抵抗。分析各组之间氯吡格雷抵抗发生率的差异。观察各组12个月随访支架内血栓与心血管事件发生率。结果 强代谢组、中代谢组、弱代谢组分别为137例（44.2%）、134例（43.2%）、39例（12.6%）,三组之间氯吡格雷抵抗发生率有统计学差异。12个月随访中弱代谢组联合心血管不良事件发生率显著高于强代谢组(P<0.05),其中非致死心梗和支架内血栓发生率显著高于强代谢组(P<0.05),而死亡及再次血运重建率两组比较差异无统计学意义(P>0.05);中弱代谢组再次住院率也显著高于强代谢组。结论 急性冠脉综合征患者PCI术后CYP2C19*2、CYP2C19*3基因变异氯吡格雷抵抗发生率更高,支架内血栓及心血管不良事件发生率明显升高。     

Evaluation of the INNOVANCE PFA P2Y assay and its association with CYP2C19 genotypes

The purpose of this study was to evaluate associations between INNOVANCE PFA P2Y (PFA P2Y) test results and CYP2C19 genotypes and provide baseline data for PFA P2Y testing to establish a therapeutic monitoring strategy for clopidogrel. A total of 75 new patients with acute coronary syndrome with planned percutaneous coronary intervention were enrolled between June 2012 and September 2012. All patients received clopidogrel at an initial loading dose of 600?mg followed by a 75-mg daily maintenance dose. Blood samples were obtained on the third morning after clopidogrel loading. PFA P2Y, VerifyNow P2Y12 and VASP assays were used to determine platelet inhibition due to clopidogrel, and the Verigene CYP2C19 test was used for CYP2C19 genotyping. The genotype frequency of 75 patients was as follows: CYP2C19 *1/*1 (wild type), 28 (37.3%); *1/*2, 31 (41.3%); *1/*3, 4 (5.3%); *2/*2, 5 (6.7%); *2/*3, 5 (6.7%); *1/*17, 1 (1.3%); and *2/*17, 1 (1.3%). Classified according to CYP2C19 genotypes, there were 29 (38.7%) extensive metabolizers (EM) or ultra rapid metabolizers (UM), 35 (46.7%) intermediate metabolizers (IM), and 10 (13.3%) poor metabolizers (PM). Median (interquartile range) PFA P2Y closure times (seconds) were 119 (101–260), 300 (130–300) and 300 (300–300) in the PM, IM and EM or UM groups, respectively (p?<?0.05). Median (interquartile range) VerifyNow PRUs were 294 (213–297), 215 (165–320) and 189 (118–279); and the VASP platelet reactivity index (%) was 52.7 (33.3–91.9), 59.9 (41.4–72.8) and 38.9 (26.8–62.2) in the PM, IM and EM or UM groups, respectively (p?>?0.05). Compared with non-carriers, carriers of reduced function CYP2C19 alleles tended to have higher platelet reactivity after clopidogrel treatment. The cut-off for PM versus other groups (IM and EM or UM) was ≤141 seconds (AUC 0.704, sensitivity 70%, specificity 76.6%) on the ROC curve. A statistically significant correlation between PFA P2Y (seconds) and VerifyNow (PRU) was found (ρ?=??0.47, p?<?0.0001). In conclusion, the PFA P2Y test showed a statistically significant association with CYP2C19 metabolizer phenotypes based on CYP2C19 genotyping and effectively determined the risk groups resistant to clopidogrel therapy, including PM.     

CYP2C19功能缺失性等位基因与老年冠心病患者支架植入术后氯吡格雷抗血小板反应性和疗效的药物基因组学研究

目的：探讨编码CYP2C19酶的基因（CYP2C19）功能缺失性（LOF）等位基因与老年冠心病患者支架植入术后氯吡格雷抗血小板反应性和临床心血管终点事件的关联性。方法连续募集2011年9月1日至2012年12月1日期间在解放军总医院住院拟行经皮冠状动脉介入术（PCI）、年龄≥65岁的老年冠心病患者,术前给予氯吡格雷负荷剂量（300mg）治疗,手术当日测定血小板聚集率,采用SNaPshot法进行CYP2C19 LOF等位基因型（CYP2C19＊2和CYP2C19＊3）检测,并记录在院临床资料。所有患者均在PCI术后1年规律服用阿司匹林和氯吡格雷,随访1年内主要心血管缺血和出血事件的发生率。结果在436例符合入选标准的老年冠心病患者中,CYP2C19＊2携带者与氯吡格雷负荷剂量治疗后的抗血小板反应性之间存在显著相关性（P＝0.001）,但在CYP2C19＊3携带者中未见上述相关性（P＝0.884）。CYP2C19＊2和至少一个CYP2C19 LOF携带者1年内心血管终点事件的发生率较非携带者均明显增加（P＜0.05）。与非携带者相比,CYP2C19＊2携带者因心绞痛再入院的发生率明显增加[校正比值比（OR）：1.67,95%可信区间（CI）：1.05～2.65,P＝0.010]。至少一个CYP2C19 LOF携带者的联合心血管事件（校正OR：1.22,95%CI：1.03～1.98,P＝0.049）和因心绞痛再入院（校正OR：1.67,95%CI：1.04～2.68,P＝0.032）的发生率较非携带者明显增加。结论 CYP2C19 LOF等位基因与老年冠心病患者PCI术后的氯吡格雷抗血小板反应性密切相关,并可明显削弱PCI术后双联抗血小板的治疗效果,导致PCI术后1年内的心血管终点事件发生风险明显增加。     

CYP2C19*2 and prognosis after an acute coronary syndrome: Insights from a Portuguese center

BackgroundClopidogrel requires oxidation dependent on the cytochrome P450 enzyme 2C19 (CYP2C19) to form its active metabolite. The importance of loss-of-function alleles (particularly CYP2C19*2, 681G>A) in poor platelet response to clopidogrel is well recognized.ObjectiveTo investigate the prevalence and prognostic impact of the CYP2C19*2 allele in a local acute coronary syndrome (ACS) population.MethodsWe performed a prospective, longitudinal study of 95 patients admitted for an ACS between March and October 2009 to a single coronary care unit. Patients aged under 75 who survived hospital stay and for whom clopidogrel was prescribed were included. At discharge, CYP2C19 was genotyped using a commercially available kit. Patients were divided into two groups: Group A (non-carriers, normal metabolizers, CYP2C19*1/*1), n = 69; and Group B (carriers, slow metabolizers, CYP2C19*2/*1 or *2/*2), n = 26. The primary endpoint was a combined outcome of cardiovascular death, non-fatal myocardial infarction or re-admission for unstable angina; median follow-up was 136.0 (79.0–188.0) days.ResultsThe median age of the population was 62.0 (51.0–68.0) years, and 83.2% were male. The CYP2C19*2 (A) allele had a frequency of 14.2%. There were no differences between the groups with respect to demographic data or history of cardiovascular disease. Coronary anatomy, left ventricular ejection fraction and renal function were also similar. The groups were also homogenous with respect to GRACE risk score (118.0 (95.0–136.5) vs. 115.0 (96.0–133.0), p = 0.68), medical treatment and percutaneous revascularization during hospital stay. Event-free survival was higher for Group A (94.0% vs. 75.0%, log-rank p = 0.010). Three readmissions for MI were documented, all in the slow metabolizers group.ConclusionIn our ACS population, the CYP2C19*2 allele was a medium-term prognostic marker.     

Comparison of ticagrelor and clopidogrel in the treatment of patients with coronary heart disease carrying CYP2C19 loss of function allele

BackgroundClopidogrel is a traditional P2Y12 receptor inhibitor that is widely used in clinical practice, but there are significant individual differences in its therapeutic effect. Carriers of the CYP2C19 deletion allele have a higher risk of adverse cardiovascular events than non-carriers.MethodsIn this study, 170 patients diagnosed with coronary heart disease (CHD) and on regular oral clopidogrel or ticagrelor antiplatelet therapy in the Department of Cardiology of Wuxi Second People’s Hospital from August to December 2019 were screened. Baseline patient data were collected, percutaneous coronary angiography (CAG) or coronary computed tomography angiography (CTA) results were recorded, CYP2C19 gene type was detected, and prognosis/outcome was assessed by telephone/outpatient/inpatient follow-up for 12 months.Results(I) Of the 170 patients, 0.66% were the fast metabolic type, 41.45% were the normal metabolic type, 42.76% were the intermediate metabolic type, and 15.13% were the poor metabolic type. CYP2C19*2 mutation accounted for 89.29% of all mutations, CYP2C19*3 mutation accounted for 9.82%, and CYP2C19*17 mutation accounted for only 0.89%. (II) Among the patients with CHD who regularly took clopidogrel, the risk in the intermediate metabolic group was 5.208-fold higher than that of normal metabolic group, and that of the poor metabolic group was 3.75-fold higher than that of normal metabolic group; there was no significant difference between the intermediate and poor metabolic groups. (III) Prognosis was significantly associated with regular use of ticagrelor or clopidogrel by patients in the intermediate metabolic group. There was no significant correlation between poor metabolism (PM) and normal metabolism (NM). Prognosis was significantly associated with regular use of ticagrelor or clopidogrel in patients undergoing percutaneous coronary intervention (PCI), but not in patients who did not undergo PCI.ConclusionsCYP2C19 polymorphism was associated with the prognosis of patients with CHD administered antiplatelet therapy with oral clopidogrel. The incidence of poor prognosis was significantly increased with CYP2C19*2 and/or CYP2C19*3 mutations, and patients undergoing PCI or carrying a single CYP2C19 deletion allele had a better prognosis with ticagrelor as replacement therapy.     

Clopidogrel Pharmacogenetics in Iranian Patients Undergoing Percutaneous Coronary Intervention

Clopidogrel is used in patients with coronary syndromes and at risk of thrombotic events or receiving percutaneous coronary intervention (PCI) for reducing heart attack and stroke. Here we present genotype and phenotype study of Iranian patients undergoing PCI treated with clopidogrel during a 6-month period of follow-up; common variants of CYP2C19, CYP3A5, CYP3A4, and ABCB1 genes were determined as well as the patients’ cardiovascular outcomes to find out the effect of these variants individually and in combination. 388 individuals receiving PCI were enrolled in this study. Different pretreatment doses of clopidogrel were prescribed under the interventional cardiologists’ guidance. The patients were followed for a duration of 1 month, and 6 months. Six SNPs were selected for genotyping including CYP2C19*2 (c.681G?>?A), CYP2C19*3 (c.636G?>?A), CYP2C19*17 allele (c.?806C?>?T), ABCB1 (c.3435C?>?T), CYP3A5 (c.6986A?>?G), and CYP3A4 (c.1026?+?12G?>?A). The mean loading dose was 600 mg/day in 267 (68.8%) individuals, 300 mg/day in 121 (31.2%). 8 patients had cardiovascular events such as thrombosis, unstable angina, and non-STEMI. The studied alleles and genotypes were in Hardy–Weinberg equilibrium. None of the SNPs individually were significantly associated with outcome events. Our results indicate that combinations of different alleles of genes are involved in pharmacokinetic variability and joint factors are important; this means that genotyping and analysis of an individual variant may not be as straightforward in risk assessment and pharmacogenetics. This highlights the importance of personalized medicine in risk assessment and treatment.     

Factors determining clinical effectiveness of clopidogrel and prognosis of patients with stable ischemic heart disease

Aim of the study was to elucidate genetic and drug factors affecting efficacy of clopidogrel in patients with ischemic heart disease - inhabitants of central region of Russian Federation. We included 399 patients with IHD (79% men, mean age 58.3+/-9 years) receiving long term therapy with clopidogrel 75 mg/day (during stable manifestations of the disease) or 75-150 mg/day in combination with aspirin (in relation with recent elective percutaneous interventions). We studied carriage of polymorphisms of genes controlling intestinal absorption of clopidogrel (ABCB1 C3435T), activation of clopidogrel in the liver (CYP2C19 *1 *2), and also registered concomitant administration of proton pump inhibitors (PPI). Then we determined relationship of these factors to development of vascular complications (vascular death/myocardial infarction/requirement in revascularization) during 18 months followup. Among studied genetic factors carriage of allele variants CYP2C19 *1/*2 and *2/* (found in 25.5 and 1.8% of patients, respectively), possessed prognostic significance. In the group of clopidogrel monotherapy carriage of at least one *2 allele was associated with increased rate of vascular complications (33.3% vs. 11.3%) including thrombotic complications (27.7% vs. 3.2%; =0.01). In patients receiving 75 mg/day of clopidogrel in combination with aspirin total rate of thrombotic complications as well as of all adverse unfavorable outcomes was higher in *2 carriers compared with wild type homozygotes (14.0% vs.8.7% and 21.0% vs. 15.8%, respectively). In patients receiving double dose clopidogrel in combination with aspirin we found no worsening of outcomes associated with CYP2C19*2 carriage. In the multifactorial risk model independent predictors of vascular complications turned out to be CYP2C19 *2/*2 homozygosity (RR 4.9; =0.02) and concomitant PPI administration ( 1.8; p=0.05).     

Risk of stroke in CYP2C19 LoF polymorphism carrier coronary artery disease patients undergoing clopidogrel therapy: An ethnicity-based updated meta-analysis

BackgroundAntiplatelet agent clopidogrel has been widely used for stroke management for many years, although resistance to clopidogrel may increase the chance of stroke recurrence. CYP2C19 loss-of-function (LoF) polymorphism is assumed to be responsible for the poor metabolism of clopidogrel that ultimately turns to resistance. Previous publications could not provide firm evidence due to highly conflicting and heterogeneous outcomes.AimTo get clear evidence from an updated meta-analysis on CYP2C19 LoF polymorphism association with stroke risk in clopidogrel treated patients, this study has been performed.MethodsWe conducted a meta-analysis with 72 selected studies from authentic databases, including 40,035 coronary artery disease patients treated with clopidogrel.ResultsThis analysis showed that the worldwide carrier of one or more CYP2C19 LoF alleles had a significantly higher risk of stroke and composite events than the non-LoF carriers (RR=1.78, 95% CI=1.52-2.07, p<0.00001 and RR=1.39, 95% CI=1.26-1.54, p<0.00001, respectively). Besides, subgroup analysis showed that Asian CYP2C19 LoF carriers had a significantly increased risk of stroke (RR=1.91, 95% CI=1.60-2.28, p<0.00001) while the risk of composite events was significantly higher in all ethnic populations (Asian: RR=1.58, 95% CI=1.32-1.89, p<0.00001; Caucasian: RR=1.27, 95% CI=1.08-1.50, p=0.003; Hispanic and others: RR=1.21, 95% CI=1.09-1.34, p=0.0003).ConclusionOur meta-analysis confirmed that the presence of CYP2C19 LoF alleles increases the risk of stroke and composite events recurrence in the worldwide population, especially in Asians undergoing clopidogrel treatment. Alternative antiplatelet therapy should be investigated thoroughly for the intermediate and poor metabolizers.     

Switching from prasugrel to clopidogrel based on Cytochrome P450 2C19 genotyping in East Asian patients stabilized after acute myocardial infarction

To evaluate the pharmacodynamic efficacy of de-escalating P2Y₁₂ inhibition from prasugrel to clopidogrel based on cytochrome P450 (CYP) 2C19 genotyping, we genotyped 50 Korean patients with AMI who underwent percutaneous coronary intervention (PCI) for CYP2C19 *2,*3, or *17 using real-time PCR. They were discharged on prasugrel 10 mg daily. A control group of 48 AMI patients who underwent PCI and were discharged on clopidogrel but did not undergo genotyping was identified retrospectively. Based on genotyping results available at 3 weeks, 12 patients found to have 2 copies of either CYP2C19 *2 or *3 loss of function alleles continued prasugrel while the remaining 38 patients switched to clopidogrel 75 mg daily. The rate of patients within the therapeutic window (TW) of on-treatment platelet reactivity (OPR), 85<P2Y₁₂ reactivity unit (PRU) ≤275, was compared in the genotype-directed cohort before (3 weeks) and after genotype-directed antiplatelet treatment (5 weeks), as well as with the control cohort at 5 weeks. In the genotype-directed group, there was an increase in the proportion of patients within the TW after genotype-directed antiplatelet treatment (48–76%, p=0.007), primarily driven by a decrease of patients with PRU <85 (52–16%, p <0.001). The proportion of patients within the TW was similar between the genotype-guided and control groups (76% vs. 72.9% p=0.726). In conclusion, individualized antiplatelet regimens based on CYP2C19 genotyping may improve likelihood of achieving a TW of OPR compared to fixed dose of prasugrel 10 mg during maintenance periods of AMI in East Asians.     

Defining predictive values using three different platelet function tests for CYP2C19 phenotype status on maintenance dual antiplatelet therapy after PCI

Abstract

Published data suggests that the presence of CYP2C19*2 or *3 loss of function (LOF) alleles is indicative of increased platelet aggregation and a higher risk of adverse cardiovascular events after clopidogrel administration. We sought to determine cut-off values using three different assays for prediction of the CYP2C19 phenotype in Korean percutaneous coronary intervention (PCI) patients. We enrolled 244 patients with drug-eluting stent implantation who were receiving clopidogrel and aspirin maintenance therapy for one month or more. Platelet reactivity was assessed with light transmittance aggregometry (LTA), multiple electrode aggregometry (MEA) and the VerifyNow P2Y12 assay (VN). The CYP2C19 genotype was analyzed by polymerase chain reaction (PCR) and snapshot method. The frequency of CYP2C19 LOF allele carriers was 58.6%. The cut-off values from LTA, MEA and VerifyNow for the identification of LOF allele carriers were as follows: 10?µM ADP-induced LTA?≥?48 %, VN?>?242 PRU and MEA?≥?37?U. Between the three tests, correlation was higher between LTA vs. VN assays (r?=?0.69) and LTA vs. MEA (r?=?0.56), with moderate agreement (κ?=?0.46 and κ?=?0.46), but between VN assay and MEA, both devices using whole blood showed a lower correlation (r?=?0.42) and agreement (κ?=?0.3). Our results provide guidance regarding cut-off levels for LTA, VerifyNow and MEA assays to detect the CYP2C19 LOF allele in patients during dual antiplatelet maintenance therapy.     

CYP2C19基因多态性与介入治疗后氯吡格雷药物疗效的相关性研究

目的探讨PCI术后CYP2C19基因多态性与不同剂量氯吡格雷药物效果的相关性。方法通过基因芯片检测技术,筛选PCI术后CYP2C19基因突变为CYP2C19*2/*2、CYP2C19*2/*3或CYP2C19*3/*3的患者67例,随机分为常规组22例、2倍组22例和3倍组23例。常规组75 mg氯吡格雷、2倍组150 mg氯吡格雷、3倍组225 mg氯吡格雷,1次/d。分别于PCI术后1、3、6个月通过血栓弹力图检测各组氯吡格雷药物抑制率及再发心血管缺血事件发生率。结果 PCI术后6个月内,2倍组和3倍组患者心血管缺血事件发生率较常规组明显降低(81.8%vs 31.8%vs 21.7%,P<0.01),2倍组与3倍组比较差异无统计学意义(P>0.05)。术后1、3、6个月2倍组和3倍组氯吡格雷药物抑制率较常规组显著升高(P<0.01),2倍组与3倍组比较差异无统计学意义(P>0.05)。3组出血风险比较差异无统计学意义(P>0.05)。结论 CYP2C19基因变异患者增加氯吡格雷药物服用剂量,可在一定程度上提高血小板的抑制,降低心血管缺血事件发生率,且不增加出血事件的发生率。     

Routine CYP2C19 Genotyping to Adjust Thienopyridine Treatment After Primary PCI for STEMI: Results of the GIANT Study

ObjectivesThe aim of this study was to evaluate prospectively the clinical impact of routine transmission of CYP2C19 genotype in the management of acute ST-segment elevation myocardial infarction with primary percutaneous coronary intervention.BackgroundResponse to clopidogrel differs widely among patients, notably because of CYP2C19 genetic polymorphisms.MethodsCYP2C19 genotype (6 alleles) was determined centrally and communicated within 4.1 ± 1.9 days of primary percutaneous coronary intervention in 1,445 patients with ST-segment elevation myocardial infarction recruited at 57 centers in France. CYP2C19 metabolic status was predicted from genotype and served to adjust thienopyridine treatment. The primary endpoint was differences in 12-month outcomes (death, myocardial infarction, and stent thrombosis) between patients with the wild-type genotype or gain-of-function allele (class 1, n = 1,118) and those with loss-of-function (LOF) alleles (class 2, n = 272) who received optimized thienopyridine treatment.ResultsDetection of LOF alleles resulted in adjustment of P2Y₁₂ inhibition in 85% of patients, with significantly higher use of prasugrel or double-dose clopidogrel. The primary endpoint did not differ between class 1 and class 2 patients (3.31% vs. 3.04%, respectively; p = 0.82). In contrast, carriers of LOF alleles without treatment adjustment had significantly worse outcomes (15.6%; p < 0.05). Bleeding rates were not different between groups.ConclusionsIn a real-world setting, a complete CYPC2C19 genotype can be mostly determined in <7 days using analysis of saliva deoxyribonucleic acid collected during the in-hospital phase among patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. Genotype information led to stronger platelet inhibition treatment in the vast majority of LOF allele carriers and to similar clinical outcomes as in patients carrying the wild-type genotype or gain-of-function allele. (Genotyping Infarct Patients to Adjust and Normalize Thienopyridine Treatment [GIANT]; NCT01134380)     

Next-Generation Sequencing of CYP2C19 in Stent Thrombosis: Implications for Clopidogrel Pharmacogenomics

Purpose

Describe CYP2C19 sequencing results in the largest series of clopidogrel-treated cases with stent thrombosis (ST), the closest clinical phenotype to clopidogrel resistance. Evaluate the impact of CYP2C19 genetic variation detected by next-generation sequencing (NGS) with comprehensive annotation and functional studies.

Methods

Seventy ST cases on clopidogrel identified from the PLATO trial (n =?58) and Mayo Clinic biorepository (n =?12) were matched 1:1 with controls for age, race, sex, diabetes mellitus, presentation, and stent type. NGS was performed to cover the entire CYP2C19 gene. Assessment of exonic variants involved measuring in vitro protein expression levels. Intronic variants were evaluated for potential splicing motif variations.

Results

Poor metabolizers (n =?4) and rare CYP2C19*8, CYP2C19*15, and CYP2C19*11 alleles were identified only in ST cases. CYP2C19*17 heterozygote carriers were observed more frequently in cases (n =?29) than controls (n =?18). Functional studies of CYP2C19 exonic variants (n =?11) revealed 3 cases and only 1 control carrying a deleterious variant as determined by in vitro protein expression studies. Greater intronic variation unique to ST cases (n =?169) compared with controls (n =?84) was observed with predictions revealing 13 allele candidates that may lead to a potential disruption of splicing and a loss-of-function effect of CYP2C19 in ST cases.

Conclusion

NGS detected CYP2C19 poor metabolizers and paradoxically greater number of so-called rapid metabolizers in ST cases. Rare deleterious exonic variation occurs in 4%, and potentially disruptive intronic alleles occur in 16% of ST cases. Additional studies are required to evaluate the role of these variants in platelet aggregation and clopidogrel metabolism.

     

Association between cytochrome P450 2C19 polymorphism and clinical outcomes in Chinese patients with coronary artery disease

BackgroundCytochrome P450 (CYP)2C19 is expressed in vascular endothelium and metabolizes arachidonic acid to biologically active epoxyeicosatrienoic acids, which play a key role in regulating vascular tone. The aim of this study was to investigate whether the genetic functional variant 681G > A (*2) of cytochrome CYP2C19 is associated with adverse cardiovascular outcomes in Chinese patients with coronary artery disease (CAD).MethodsBetween July 2008 and September 2009, 654 consecutive patients with CAD were enrolled in this study. All participants underwent CYP2C19 genotyping. The primary study endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. Secondary endpoints included the components of the primary endpoint, death from any cause, and recurrent revascularization.ResultsThe baseline characteristics were well-balanced between carriers (heterozygous *1/*2, n = 291; homozygous *2/*2, n = 57) and non-carriers (n = 306) of the CYP2C19*2 variant. During the follow-up period (11.42 ± 4.23 months), the primary endpoint occurred more frequently in homozygous *2/*2 than in non-carriers (n = 306) of CYP2C19*2 variant (12.28% versus 3.27%; adjusted hazard ratio [HR] = 5.191; 95% confidence interval [CI] = 1.936–13.917; P = 0.001); however, no such increase was evident in heterozygous *1/*2 patients (4.12% versus 3.27%; adjusted HR = 1.208; 95% CI 0.517–2.822; P = 0.662).ConclusionsThe homozygous CYP2C19*2/*2 genotype is an independent determinant of adverse vascular events in Chinese patients with CAD.     

细胞色素P4502 C19快代谢基因型缺血性卒中患者氯吡格雷抵抗的影响因素分析

目的 探讨细胞色素P4502C19(CYP2C19)快代谢基因型缺血性卒中患者氯吡格雷抵抗的影响因素.方法 回顾性连续纳入CYP2C19快代谢基因型(CYP2C19*1/*1)缺血性卒中住院患者204例,均于确诊后连续服用氯吡格雷75 mg/d,共7 d,第8天晨起空腹抽取静脉血,2 h内完成血栓弹力图血小板图的检测....