CYP2C19基因多态性与氯吡格雷抵抗的关系及对冠心病PCI患者短期预后的影响

目的探讨冠心病(CHD)患者CYP2C19基因多态性与氯吡格雷抵抗的关系及对接受经皮冠状动脉介入治疗(PCI)的CHD患者短期预后的影响。方法接受PCI治疗的CHD患者352例,均行PCI治疗,治疗后进行基因型测定、血小板活性测定及氯吡格雷抵抗测定。对比CYP2C19基因野生亚型组和突变亚型组患者的基线资料、氯吡格雷抵抗率及血小板凝集率,统计CYP2C19基因型的各亚型比例,随访1年,对比野生亚型组和突变亚型组的预后情况。结果野生亚型组和突变亚型组基线资料比较差异无统计学意义(P>0.05)。352例患者CYP2C19基因型检测结果显示,野生亚型组166例,突变亚型组186例。CYP2C19基因型共有6种:(*1/*1)、(*1/*2)、(*1/*3)、(*2/*2)(*2/*3)(*3/*3),各亚型比例分别为166例(47.2%)、138例(39.2%)、27例(7.7%)、10例(2.8%)、10例(2.8%)和1例(0.3%)。突变亚型组的氯吡格雷抵抗率、血小板凝集率均高于野生亚型组(P<0.05)。Kaplan-Meier生存分析发现,在PCI患者中,CYP2C19野生亚型组患者预后明显优于突变亚型组(P<0.05)。结论 CYP2C19基因多态性显著影响PCI预后,CHD患者PCI术后CYP2C19*2、CYP2C19*3基因变异型的氯吡格雷抵抗率更高,心血管不良事件发生率明显升高。     

CYP2C19基因多态性对颈动脉支架植入术后支架内血栓形成的影响

目的阐明CYP2C19基因多态性与颈动脉支架植入术(CAS)后支架内血栓形成、氯吡格雷抵抗之间的关系。方法入选2013年1月至2014年12月南京医科大学附属脑科医院老年神经科及神经科接受颈内动脉动脉支架(裸支架)植入术的首次住院颈内动脉狭窄患者102例,服用阿司匹林100 mg/d,颈内动脉支架植入术前3 d开始予氯吡格雷75 mg/d口服。多重高温连接酶检测反应进行CYP2C19*2和*3位点分型,并记录氯吡格雷抵抗和支架内血栓形成的发生率。结果入选的102例患者中,按CYP2C19*2分型:CYP2C19*1*1型45例,CYP2C19*1*2型47例,CYP2C19*2*2型10例。携带CYP2C19*2基因者氯吡格雷抵抗的发生率为26.3%(15例),未携带CYP2C19*2基因者氯吡格雷抵抗的发生率为13.3%(6例),组间差异有统计学意义(P<0.05)。携带CYP2C19*2基因者颈内动脉支架植入术后支架内血栓形成的发生率为19.3%(11例),未携带CYP2C19*2基因者支架内血栓形成的发生率为11.1%(5例),组间差异有统计学意义(P<0.05)。结论CYP2C19*2基因位点的多态性可能是颈内动脉支架植入术后不良事件发生的危险因素。     

沈阳地区汉族人群CYP2C19基因代谢型分布及临床用药指导

目的研究沈阳地区汉族人群中氯吡格雷基因代谢型的分布情况,以指导临床用药。方法收集2016年9月—2017年8月于沈阳医学院附属第二医院体检及住院的病人96例,应用多重荧光定量PCR探针法对其CYP2C19的基因多态性进行检测,研究氯吡格雷基因代谢型的分布情况,根据其对抗血小板聚集药物氯吡格雷的药物敏感性,为病人提供用药指导。结果本研究共检测到7种基因型,分别为:*1/*1(38.54%),*1/*2(33.33%),*2/*2(14.58%),*1/*3(7.29%),*2/*3(2.08%),*1/*17(3.12%),*2/*17(1.04%),其中CYP2C19*1位点突变占60.4%,CYP2C19*2位点突变占32.8%,CYP2C19*3位点突变占4.7%,CYP2C19*17位点突变占2.1%。4种代谢型:慢代谢型(*2/*2,*2/*3,*3/*3)占16.7%,中等代谢型(*1/*2,*1/*3,*2/*17,*3/*17)占40.6%,快代谢型(*1/*1)占38.5%,超快代谢型(*1/*17,*17/*17)占4.2%。结论 CYP2C19中,慢代谢型病人所占比例高,鉴于*2、*3基因携带者在植入支架后再形成血栓的风险高,对拟行经皮冠状动脉介入治疗(PCI)术并用氯吡格雷治疗的病人,进行个体化的CYP2C19基因检测,具有十分重要的临床意义。     

北京地区汉族冠心病患者CYP2C19基因多态性的研究分析

目的:探讨北京地区汉族冠心病患者细胞色素P450(CYP)2C19基因多态性的分布特征及其与氯吡格雷抵抗、支架内血栓的相关性。方法:入选800例无亲缘关系的冠心病患者,检测其CYP2C19基因型,和ADP诱导的血小板聚集率,确定是否存在氯吡格雷抵抗(CR),并分为CR组(215例),NCR组(585例),比较两组携带基因型及冠脉支架内血栓发生率。结果:CYP2C19分为三种表型,快代谢型(基因型为CYP2C19*1/*1)、中间代谢型(基因型为CYP2C19*1/*2和*1/*3)、慢代谢型(基因型为CYP2C19*2/*2、*2/*3)。入选冠心病患者携带快代谢型*1/*1(41.6%),中间代谢型*1/*2,*1/*3(46.8%)较多,以中间代谢型显著较多;CR组215例,即氯吡格雷抵抗发生率为26.9%(215/800)。与NCR组比较,CR组患者携带快代谢型基因型*1/*1(43.9%比35.3%)明显减少,而携带慢代谢型基因型*2/*2,*2/*3(9.9%比17.2%)明显较多(P0.05或0.01)。本研究中共有15例(1.88%)发生确定的支架内血栓,其中10例(4.65%)为CR组,5例(0.85%)为NCR组,即CR组的支架内血栓事件率显著高于NCR组(P0.01)。结论:北京地区汉族冠心病患者携带P450(CYP)2C19基因中间代谢型最多;氯吡格雷抵抗发生率26.9%,CR组携带慢代谢型基因型显著多于NCR组;CR组的支架内血栓事件率显著高于NCR组。     

CYP2C19基因多态性对老年冠心病PCI术后抗血小板治疗的影响

目的探讨中国南方汉族人中CYP2C19基因多态性与冠心病(CHD)氯吡格雷治疗后血小板活性的关系。方法选取拟行冠脉介入术治疗的中国南方汉族老年CHD患者193例,均给予氯吡格雷300 mg负荷剂量,75 mg qd维持剂量。通过流式细胞仪检测血小板聚集率,采用聚PCR RFLP法基因型进行CYP2C19基因型检测。根据不同的基因型人群间氯吡格雷的药物代谢动力学特征把携带野生型基因(*1/*1)归为快代谢型,突变杂合型(*1/*2、*1/*3)为中间代谢型、突变纯合型(*2/*2、*2/*3、*3/*3)为慢代谢型。观察患者在服用氯吡格雷等药物治疗后7 d及14 d血小板聚集率的情况。结果野生型与中间代谢型、慢代谢型组间血小板聚集程度比较差异有统计学意义(P0.05)。中间代谢型、慢代谢型7 d组血小板活性降低程度显著优于7 d组,患者CYP2C19基因慢代谢型的比例为9.84%;心血管事件占8.08%,与野生型基因患者相比有差异(P0.05)。结论 CYP2C19基因突变与CHD PCI术后氯吡格雷治疗血小板活性有关。     

CYP2C19基因多态性与冠心病患者PCI术后氯吡格雷抵抗的关系

目的:探讨CYP2C19基因多态性对冠心病患者经皮冠状动脉介入治疗(PCI)术后氯吡格雷抵抗(CR)的影响。方法:选择在我院接受治疗并进行PCI手术的冠心病患者100例,其中CR 24例,无氯吡格雷抵抗(NCR)76例。根据CYP2C19基因型,患者被分为快代谢型CYP2C19*1/*1 (49例),中间代谢型CYP2C19*1/*2(28例)和*1/*3 (11例),慢代谢型CYP2C19*2/*2 (9例)和*2/*3 (3例)。分析不同基因型与CR、最大血小板聚集率(MPA)、主要不良心血管事件(MACE)发生的关系。结果:以快代谢型CYP2C19*1/*1基因型为基础,中间代谢型CYP2C19*1/*2和*1/*3 (OR=4.16、5.03,P均0.05)及慢代谢型CYP2C19*2/*2和*2/*3 (OR=7.04、17.6,P均0.01)发生CR的风险显著增加,中间代谢型分别增加4.16和5.03倍,慢代谢型分别增加7.04和17.60倍;与快代谢基因型比较,中、慢代谢基因型的MPA和MACE发生率均显著增加(P0.05或0.01);CR组MACE发生率显著高于NCR组(20.8%比5.3%,P=0.02)。结论:CYP2C19基因多态性对冠心病患者PCI术后氯吡格雷抵抗有一定的影响,带有中、慢代谢基因型冠心病患者更易发生氯吡格雷抵抗以及有更高的最大血小板聚集率和主要不良心血管事件发生率。     

CYP2C19指导ACS行PCI患者抗血小板药物选择的研究

目的:根据急性冠状动脉综合征(ACS)行经皮冠状动脉介入治疗(PCI)患者CYP2C19基因型的不同选择抗血小板药物及剂量进行治疗,观察其抗血小板效应及出血风险,为个体化抗血小板药物的选择提供参考。方法:入选231例行PCI的ACS患者并检测其CYP2C19基因型,根据基因型的不同分为快代谢组(CYP2C19*1/*1)、中代谢组(CYP2C19*1/*2、CYP2C19*1/*3)、慢代谢组(CYP2C19*2/*2、CYP2C19*3/*3、CYP2C19*2/*3),并分别给予快代谢组常规双联抗血小板治疗(氯吡格雷75mg qd+阿司匹林100mg qn),中代谢组氯吡格雷剂量加倍(氯吡格雷150mg qd+阿司匹林100mg qn),慢代谢组换用新型抗血小板药物(替格瑞洛90mg bid+阿司匹林100mg qn),比较各组用药3个月后血小板抑制率变化情况及出血事件的发生情况。结果:根据基因型所分3组的临床基线资料及PCI结果无统计学差异。中代谢组及慢代谢组患者用药3个月后,血小板抑制率均较快代谢组血小板抑制率升高,慢代谢组血小板抑制率较中代谢组明显升高,差别具有统计学意义(均P0.05)。结论:PCI术后的ACS患者中,携带CYP2C19*2、CYP2C19*3等位基因的高危患者,采用氯吡格雷剂量加倍及换用替格瑞洛均可充分抑制血小板,且换用替格瑞洛优于氯吡格雷剂量加倍。     

缺血性卒中患者细胞色素P450 2C19基因多态性与氯吡格雷抗血小板聚集的关系

目的探讨缺血性卒中患者细胞色素P450 2C19(CYP2C19)基因多态性与服用氯吡格雷后血小板抑制率之间的关系。方法前瞻性纳入251例首都医科大学宣武医院门诊及住院需要服用氯吡格雷的缺血性卒中患者为研究对象。检测与氯吡格雷代谢相关的CYP2C19基因,依据CYP2C19基因位点分为快代谢型(*1/*1)97例、中间代谢型(103例*1/*2和18例*1/*3)1 2 1例、弱代谢型(2 4例*2/*2和9例*2/*3)3 3例。在服用氯吡格雷75 mg/d的第8天晨起抽取静脉血,用血栓弹力图检测二磷酸腺苷诱导的血小板抑制率。比较不同基因型患者的血小板抑制率及氯吡格雷敏感情况的差异。结果 (1)快代谢型患者氯吡格雷敏感65例(67.0%),中间代谢型患者氯吡格雷敏感70例(57.9%),弱代谢型患者氯吡格雷敏感17例(51.5%),不同代谢型间氯吡格雷敏感情况差异无统计学意义(χ~2=3.192,P=0.203)。(2)所有患者快代谢型、中间代谢型、弱代谢型患者的血小板抑制率中位数分别为39.5(20.9,56.5)%、35.6(21.1,59.8)%、30.3(11.4,48.1)%。三型之间的血小板抑制水平差异无统计学意义(H=3.287,P=0.193)。结论对于服用氯吡格雷的缺血性卒中患者,根据CYP2C19基因多态性尚不能准确预测氯吡格雷抗血小板聚集的疗效。     

CYP2C19基因多态性与PCI手术患者血小板抑制率的相关性研究

目的 研究CYP2C19基因多态性对经皮冠状动脉介入治疗（PCI）手术患者血小板抑制率的影响。方法 本研究纳入符合入选标准的2014年1月至2016年4月在解放军第一七五医院心内科住院的冠心病患者210例,均需行PCI手术治疗。所有入选者均采取静脉血标本并提取外周血基因组DNA,进行PCR 扩增及纯化,进行基因芯片杂交显色,通过生物芯片识读仪检测CYP2C19基因型,根据不同的基因型对患者进行分组。入选者服用负荷量阿司匹林+氯吡格雷24 h后采取静脉血标本,然后用血栓弹力图仪（TEG）检测并自动计算出二磷酸腺苷（ADP）诱导的血小板抑制率。结果 入选的210例患者各基因型比例分别为：（*1/*1）94例（44.8%)、（*1/*2）79例（37.6%）、（*1/*3）12例（5.7%）、（*2/*2）20例（9.5%）、（*2/*3）4例（1.9%）、（*3/*3）1例（0.5%）,其中快代谢型（EM型）94例（44.8%）、中等代谢型（IM型）91例（43.3%）、慢代谢型（PM型）25例（11.9%）,共有43例患者（20.5%）出现氯吡格雷抵抗现象（CR）。不同基因型组患者的血小板抑制率差异均有统计学意义（P<0.01）,其中PM型患者的血小板抑制率最低,IM型次之;不同基因型组患者的氯吡格雷抵抗情况差异有统计学意义（P<0.01）,其中PM型患者的CR远高于另外两组。结论 CYP2C19不同基因型对氯吡格雷抗血小板作用的影响存在显著差异,其中携带CYP2C19 *2或*3突变等位基因的PCI手术患者发生CR的风险明显增加。     

冠心病患者支架术后根据检测药物代谢酶CYP2C19基因调整抗血小板治疗的价值

目的 :探讨根据检测CYP2C19基因调整冠心病支架术后患者抗血小板治疗策略及其临床预后的价值。方法 :326例冠心病支架术后患者行CYP2C19基因检测,其中快代谢患者(CYP2C19*1/*1)128例(常规组,给予常规氯吡格雷75 mg,每天1次);中慢代谢患者(CYP2C19*1/*2、CYP2C19*1/*3、CYP2C19*2/*3、CYP2C19*2/*2、CYP2C19*3/*3)198例,随机分为氯吡格雷高维持剂量组(氯吡格雷150 mg,每天1次,99例);替格瑞洛组(替格瑞洛90 mg,每天2次,99例);观察三组患者支架术前及术后1、3、6个月血小板聚集率变化及6个月内主要不良心血管事件、出血等不良反应的发生率。结果 :氯吡格雷高维持剂量组与常规组术后1、3、6个月血小板聚集率比较,差异无统计学意义(P>0.05);而替格瑞洛组术后1、3、6个月血小板聚集率均较氯吡格雷高维持剂量组及常规组下降,差异有统计学意义(P<0.05)。氯吡格雷高维持剂量组与常规组6个月内发生主要不良心血管事件比较,差异无统计学意义(P>0.05);替格瑞洛组较氯吡格雷高维持剂量组及常规组显著减少主要不良心血管事件发生,差异有统计学意义(P<0.05),未明显增加出血不良事件的发生(P>0.05)。结论 :冠心病支架术后CYP2C19中慢代谢患者服用高维持剂量氯吡格雷未明显增加主要不良心血管事件发生,而调用替格瑞洛可显著降低血小板聚集率,减少主要不良心血管事件的发生,并不增加出血不良反应发生。     

细胞色素P4502C19基因多态性对介入术后服用氯吡格雷冠心病患者临床预后的影响

目的 探讨细胞色素P450(CYP)2C19 681G>A基因多态性对经皮冠状动脉介入治疗(PCI)后服用氯吡格雷冠心病患者临床预后的影响.方法 入选2009年1月1日至8月31日拟行PCI,并在术后服用氯吡格雷12个月的冠心病患者267例.采用MassARRAY时间飞行质谱检测入选患者CYP2C19 681G>A位点.按基因型不同,将患者分为CYP2C19*1/*1组 (n=130)和CYP2C19*2携带组(n=137).观察两组患者术后1年心绞痛复发、紧急血运重建术、急性心肌梗死、支架内血栓形成和死亡的发生情况.结果 两组患者的临床基本资料差异无统计学意义(P>0.05).PCI术后1年,CYP2C19*2携带组紧急血运重建术和联合终点事件的发生率均高于CYP2C19*1/*1组 (分别为7.3%比1.5%和8.0%比2.3%,P均<0.05).两组患者心绞痛复发、急性心肌梗死、支架内血栓形成和死亡的发生率差异均无统计学意义(P均>0.05).CYP2C19*2携带组随访1年的累积联合终点事件发生风险是CYP2C19*1/*1组的3.59倍(HR=3.59,95%CI:1.02～12.87,P<0.05).结论 CYP2C19 681G>A基因多态性可能是影响PCI术后服用氯吡格雷冠心病患者临床预后的因素.

Abstract：

Objective To investigate the impact of cytochrome P450 (CYP) 2C19 681G>A polymorphism on long-term prognosis of clopidogrel-treated Chinese patients after percutaneous coronary intervention (PCI).Methods Between January 1, 2009 and August 31,2009, 267 patients with coronary heart disease who received PCI and treated with clopidogrel for 12 months were enrolled. CYP2C19*2 was detected by MALDI-TOF MS and patients were grouped into CYP2C19*1/*1(n=130) and CYP2C19*2 carriers group (n=137). Follow-up was 12 months. The primary endpoint was angina recurrence, urgent coronary revascularization, acute myocardial infarction, stent thrombosis, death and the combined end points. Results Baseline data were similar between two groups (P>0.05).Urgent coronary revascularization and the combined end points occurred more frequently in CYP2C19*2 carriers than in CYP2C19*1/*1 patients (7.3% vs. 1.5% and 8.0% vs. 2.3% respectively,all P<0.05). But incidence of angina recurrence, acute myocardial infarction, stent thrombosis and death was similar between two groups (all P>0.05).Hazard risk of 1 year cumulative survival of CYP2C19*2 carriers group was significantly higher than CYP2C19*1/*1 group after PCI (HR=3.59, 95%CI: 1.02-12.87, P<0.05). Conclusion CYP2C19 681G>A polymorphism is a determinant of prognosis in coronary heart disease patients receiving chronic clopidogrel treatment after PCI.     

Clopidogrel Resistance: case reports of CYP2C19 gene variants in suspected coronary stent thrombosis

Clopidogrel is a widely used anti-platelet agent for the prevention of arterial thrombosis. Clopidogrel is administered as a pro-drug and metabolised to its active metabolite by the hepatic cytochrome P450 2C19 (CYP2C19) enzyme. The active metabolite is responsible for the anti-platelet activity of clopidogrel. Recent studies demonstrate that single nucleotide polymorphisms, (SNP's), in the gene for CYP2C19 result in significantly reduced production of the active metabolite of clopidogrel. Additional studies demonstrate that patients with SNP's in the CYP2C19 gene, including CYP2C19*2,*3,*4, and *5, have reduced production of the active metabolite of clopidogrel, reduced inhibition of platelet aggregation and increased incidence of coronary, cerebrovascular, and coronary stent thrombosis. We have been interested in determining the CYP2C19 genotype in cases of coronary stent thrombosis whilst on clopidogrel treatment and provide two case reports of coronary stent thrombosis whilst taking clopidogrel with subsequent CYP2C19 genotyping. As patients at risk of atherothrombosis in general, and stent thrombosis in particular, may be receiving or considered for anti-platelet therapy including clopidogrel, genotyping for CYP2C19 SNP's may be of benefit in the selection of appropriate anti-platelet therapy.     

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.     

CYP 450 2C19 polymorphisms in Indian patients with coronary artery disease

Background

Dual antiplatelet therapy is the cornerstone in the management of acute coronary syndromes (ACS) and prevention of stent thrombosis (ST). Genetic polymorphisms in CYP2C19 gene involved in hepatic activation of clopidogrel leads to clopidogrel non-responsiveness and may influence clinical outcomes. These polymorphisms in CYP2C19 gene and their impact on clinical outcome in coronary artery disease (CAD) have not been studied in Indian population.

Methods

We studied 110 consecutive patients (mean age 55.7 ± 10.7 years; 90% male) taking clopidogrel with angiographically proven CAD for various genetic polymorphisms in CYP2C19 gene. Relationship between loss of function mutation and clinical presentation with recurrent ACS including ST was analyzed.

Results

Out of 110 patients, 26 (23.64%) had normal genotype, 52 (47.23%) had loss of function mutation *2 and 39 (35.45%) had a gain of function mutation *17, 7 (6.36%) patients were undefined metabolizers (*2/*17) which were excluded from analyses. Final analyses included 103 patients, with 45 (40.90%) having loss of function. Overall 51 patients had ACS, with 27 developing recurrence while on clopidogrel. The prevalence of loss of function mutation was no different between the group with recurrences and those without recurrences (55.6% vs. 50%, p = 0.7). Two patients developed ST while on clopidogrel; both had loss of function mutation.

Conclusion

CYP2C19 gene polymorphisms are common in Indian population. Loss of function mutation status did not affect the clinical outcomes. A larger study also considering P2Y12 receptor polymorphisms together with platelet activity testing, may be required to establish the role of CYP2C19 gene polymorphisms in clinical practice.     

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....     

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.     

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.     

The efficacy and safety of CYP2C19 genotype-guided antiplatelet therapy compared with conventional antiplatelet therapy in patients with acute coronary syndrome or undergoing percutaneous coronary intervention: A meta-analysis of randomized controlled trials

Abstract

Cytochrome P450 (CYP) 2C19 genotype is closely associated with the metabolism and efficacy of clopidogrel, thereby having an important impact on clinical outcomes of patients with acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI). This study aimed to evaluate the efficacy and safety of CYP2C19 genotype-guided antiplatelet therapy in patients with ACS or undergoing PCI. PubMed, EMBASE, the Cochrane Library and clinicaltrials.gov were searched to identify randomized controlled trials (RCTs) comparing CYP2C19 genotype-guided antiplatelet therapy with conventional therapy in patients with ACS or undergoing PCI. Eight RCTs involving 6708 patients were included in this meta-analysis. CYP2C19 genotype-guided antiplatelet therapy was slightly superior to the conventional antiplatelet therapy in reducing the risk of MACE [RR(95%CI): 0.71(0.51–0.98), p = .04]. Meanwhile, the genotype-guided therapy group had significantly lower incidence of myocardial infarction [RR(95%CI): 0.56(0.40–0.78), p < .01], but similar risk of all-cause mortality, cardiovascular mortality, stent thrombosis, urgent revascularization and stroke compared to the conventional therapy group. Incidences of major/minor bleeding and major bleeding were comparable between the two groups. In patients with ACS or undergoing PCI, CYP2C19 genotype-guided antiplatelet therapy displayed benefit over conventional antiplatelet therapy in reducing the risk of MACE and myocardial infarction, without increasing bleeding risk. Further RCTs are needed to provide more evidences for CYP2C19 genotype-guided antiplatelet therapy.     

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.     

Cytochrome P450 2C19 loss-of-function polymorphism is a major determinant of clopidogrel responsiveness in healthy subjects

The capacity of clopidogrel to inhibit ADP-induced platelet aggregation shows wide intersubject variability. To determine whether frequent functional variants of genes coding for candidate cytochrome P450 (CYP) isoenzymes involved in clopidogrel metabolic activation (CYP2C19*2, CYP2B6*5, CYP1A2*1F, and CYP3A5*3 variants) influence the platelet responsiveness to clopidogrel, we conducted a prospective pharmacogenetic study in 28 healthy white male volunteers treated for 7 days with clopidogrel 75 mg/d. We observed that pharmacodynamic response to clopidogrel was significantly associated with the CYP2C19 genotype. Twenty of the subjects were wild-type CYP2C19 (*1/*1) homozygotes, while the other 8 subjects were heterozygous for the loss-of-function polymorphism CYP2C19*2 (*1/*2). Baseline platelet activity was not influenced by the CYP2C19 genotype. In contrast, platelet aggregation in the presence of 10 muM ADP decreased gradually during treatment with clopidogrel 75 mg once daily in *1/*1 subjects, reaching 48.9% +/- 14.9% on day 7 (P < .001 vs baseline), whereas it did not change in *1/*2 subjects (71.8% +/- 14.6% on day 7, P = .22 vs baseline, and P < .003 vs *1/*1 subjects). Similar results were found with VASP phosphorylation. The CYP2C19*2 loss-of-function allele is associated with a marked decrease in platelet responsiveness to clopidogrel in young healthy male volunteers and may therefore be an important genetic contributor to clopidogrel resistance in the clinical setting.