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.     

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。     

Variant recurrent risk among stroke patients with different CYP2C19 phenotypes and treated with clopidogrel

Polymorphisms of CYP2C19 have been associated with variant risk of subsequent cardiovascular events in survivors of myocardial infarction (MI) receiving clopidogrel. This study evaluated the impacts of CYP2C19 polymorphisms on stroke recurrence and other vascular events in a cohort of Chinese patients receiving clopidogrel. From Nanjing Stroke Registry Program, 625 consecutive patients with ischemic stroke were enrolled between May 2008 and April 2010. CYP2C19 variants (*2, *3, and *17) were genotyped. Clinical outcomes were determined with three monthly follow-up. The primary endpoint was a composite of vascular death, non-fatal ischemic stroke, and non-fatal MI. The second endpoint was bleeding events. The median exposure to clopidogrel was 13.2 (interquartile range, 8.9–18.0) months. Primary endpoint was observed in 85 (13.6%) patients and secondary endpoint in 13 (2.1%) patients. Frequencies of CYP2C19*1, *2, *3, and *17 alleles were 61.2, 34.0, 3.8, and 1.0%, respectively, in this patient cohort. CYP2C19 loss-of-function allele (*2 and *3, LOF) carriers were observed with higher risk of subsequent vascular events compared with non-carriers (17.2 versus 8.1%, HR?=?2.16, 95% CI: 1.31–3.56, p?=?0.003). After adjusted for age, sex, major cardiovascular risk factors, and drug agent, CYP2C19 LOF carrier was independently associated with primary endpoint (HR?=?2.31, 95% CI: 1.39–3.84, p?=?0.001). No significant association between CYP2C19 gain-of-function (*17, GOF) and clinical events was detected. In Chinese stroke survivors treated with clopidogrel, carriers of CYP2C19 LOF allele may have increased risk of recurrence.     

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.     

<Emphasis Type="Italic">CYP2C19</Emphasis> LOF and GOF-Guided Antiplatelet Therapy in Patients with Acute Coronary Syndrome: A Cost-Effectiveness Analysis

Purpose

This study aimed to examine the cost-effectiveness of CYP2C19 loss-of-function and gain-of-function allele guided (LOF/GOF-guided) antiplatelet therapy in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

Methods

A life-long decision-analytic model was designed to simulate outcomes of three strategies: universal clopidogrel (75 mg daily), universal alternative P2Y₁₂ inhibitor (prasugrel 10 mg daily or ticagrelor 90 mg twice daily), and LOF/GOF-guided therapy (LOF/GOF allele carriers receiving alternative P2Y₁₂ inhibitor, wild-type patients receiving clopidogrel). Model outcomes included clinical event rates, quality-adjusted life-years (QALYs) gained and direct medical costs from perspective of US healthcare provider.

Results

Base-case analysis found nonfatal myocardial infarction (5.62%) and stent thrombosis (1.2%) to be the lowest in universal alternative P2Y₁₂ inhibitor arm, whereas nonfatal stroke (0.72%), cardiovascular death (2.42%), and major bleeding (2.73%) were lowest in LOF/GOF-guided group. LOF/GOF-guided arm gained the highest QALYs (7.5301 QALYs) at lowest life-long cost (USD 76,450). One-way sensitivity analysis showed base-case results were subject to the hazard ratio of cardiovascular death in carriers versus non-carriers of LOF allele and hazard ratio of cardiovascular death in non-carriers of LOF allele versus general patients. In probabilistic sensitivity analysis of 10,000 Monte Carlo simulations, LOF/GOF-guided therapy, universal alternative P2Y₁₂ inhibitor, and universal clopidogrel were the preferred strategy (willingness-to-pay threshold = 50,000 USD/QALY) in 99.07%, 0.04%, and 0.89% of time, respectively.

Conclusions

Using both CYP2C19 GOF and LOF alleles to select antiplatelet therapy appears to be the preferred antiplatelet strategy over universal clopidogrel and universal alternative P2Y₁₂ inhibitor therapy for ACS patients with PCI.

     

The relationship between CYP2C19 polymorphisms and ischaemic and bleeding outcomes in stable outpatients: the CHARISMA genetics study

Aims Clinical trials have established the value of clopidogrel therapy in a wide spectrum of patients with cardiovascular diseases. Both loss- and gain-of-function single nucleotide variants of CYP2C19 genes have been identified that affect clopidogrel metabolism and anti-platelet response. We sought to determine the impact of CYP2C19 polymorphisms on ischaemic and bleeding events. Methods and results A subset of patients from the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) trial who consented to genotyping was analysed. Patients with clinically evident cardiovascular disease or multiple risk factors were enrolled in the trial. The rates of ischaemic and bleeding events were compared between carriers and non-carriers of loss-of-function and gain-of-function alleles in patients randomized to clopidogrel vs. placebo. A total of 4819 patients were genotyped and available for the analysis. Carriers of CYP2C19 loss-of-function alleles did not have an increased rate of ischaemic events. However, clopidogrel-treated patients did have a significantly lower rate of any bleeding in carriers: 36.1% (240/665) vs. 42.5% (681/1601) in non-carriers, HR: 0.80, 95% CI: 0.69-0.93, P = 0.003 (genotype/treatment interaction, P-value = 0.023). The CYP2C19 gain-of-function alleles did not affect ischaemic or bleeding endpoints. Conclusion No relationship was seen between CYP2C19 status and ischaemic outcomes in stable patients treated with clopidogrel. There was, however, significantly less bleeding with clopidogrel in carriers of the loss-of-function allele, suggesting less anti-platelet response. Although several prior studies, including mainly stented patients, have emphasized the relationship between CYP2C19 loss-of-function alleles and efficacy of clopidogrel, this study of stable patients establishes a potential link with reduced bleeding complications. Clinical Trial Registration: This study is registered with ClinicalTrials.gov number, NCT00050817.     

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.     

Multisite Investigation of Outcomes With Implementation of CYP2C19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention

Objectives

This multicenter pragmatic investigation assessed outcomes following clinical implementation of CYP2C19 genotype–guided antiplatelet therapy after percutaneous coronary intervention (PCI).

Evaluation of the <Emphasis Type="Italic">F2R</Emphasis> IVS-14A/T PAR1 polymorphism with subsequent cardiovascular events and bleeding in patients who have undergone percutaneous coronary intervention

Abnormal platelet reactivity is associated with recurrent ischemia and bleeding following percutaneous coronary intervention (PCI). Protease-activated receptor-1 (PAR1), encoded by F2R, is a high affinity thrombin receptor on platelets and the target of the antiplatelet drug vorapaxar. The intronic single nucleotide polymorphism F2R IVS-14 A/T affects PAR1 receptor density and function. We hypothesized that carriers of the T allele, who have been shown to have decreased platelet reactivity, would be at lower risk for thrombotic events, but higher risk for bleeding following PCI. Using BioVU, the Vanderbilt DNA repository linked to the electronic medical record, we studied 660 patients who underwent PCI for unstable or stable coronary artery disease. Primary outcome measures were major adverse cardiovascular events (MACE, composite of revascularization, MI, stroke, death) and bleeding (assessed by Bleeding Academic Research Consortium scale) over 24 months. The minor allele (T) frequency was 14.8 %. There were no genotypic differences in the frequency of MACE (33.7, 28.8, and 31.6 % for A/A, A/T, and T/T respectively, P = 0.50) or bleeding (15.7, 14.7, and 18.8 % for A/A, A/T, and T/T respectively, P = 0.90). In a Cox regression model, fully adjusted for age, race, sex, BMI, and smoking status, carrying a T allele was not associated with MACE (HR 1.19, 95 % CI 0.89–1.59, P = 0.23) or bleeding (HR 0.73, 95 % CI 0.37–1.4, P = 0.34). In conclusion, in our population, F2R IVS-14 PAR1 variability does not affect risk of MACE or bleeding following PCI.     

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.     

Genetic susceptibility to nonsteroidal anti-inflammatory drug-related gastroduodenal bleeding: role of cytochrome P450 2C9 polymorphisms

BACKGROUND AND AIMS: Several nonsteroidal anti-inflammatory drugs (NSAIDs) are metabolized by the cytochrome P450 2C9 (CYP2C9). Two common variants of the CYP2C9 gene (CYP2C9*2 and *3) were reported to significantly affect the activity of the CYP2C9 enzyme. The aim of this study was to evaluate the impact of CYP2C9 polymorphisms on the risk of gastroduodenal bleeding in acute NSAID users. METHODS: This case-control study included 26 patients with endoscopically documented NSAID-related gastroduodenal bleeding lesions and 52 age-, sex- and NSAID use-matched controls with no lesions at endoscopy. Both cases and controls were Helicobacter pylori negative and acute users of an NSAID or cycloxygenase-2 inhibitor that undergoes CYP2C9 metabolism (ie, celecoxib, diclofenac, ibuprofen, naproxen, or piroxicam). Two marker single nucleotide polymorphisms in the CYP2C9 gene, identifying the CYP2C9 *2 and *3 allele, were evaluated in all subjects. RESULTS: Setting the CYP2C9*1/*1 wild type as reference, significantly higher frequencies of CYP2C9*1/*3 (34.6% vs 5.8%; P < .001; odds ratio [OR], 12.9; 95% confidence interval [CI], 2.917-57.922) and CYP2C9*1/*2 (26.9% vs 15.4%; P = .036; OR, 3.8; 95% CI, 1.090-13.190) were identified in bleeding versus control patients, whereas no differences between bleeding and controls were observed in the distribution of CYP2C9*2/*3 heterozygotes. Considering allele carriers, the presence of CYP2C9*3 allele was associated with a significant high risk of bleeding (adjusted OR, 7.3; 95% CI, 2.058-26.004). CONCLUSIONS: CYP2C9 genotyping may identify subgroups of persons who potentially are at increased risk of gastroduodenal bleeding when treated with NSAIDs metabolized by CYP2C9. Further studies that evaluate the effectiveness of a strategy using CYP2C9 genotyping in NSAID users are needed before genotyping is introduced into clinical practice.     

老年冠状动脉支架植入术后患者CYP2C19基因681G＞A单核苷酸多态性与氯吡格雷抵抗的相关性

目的拟通过该项研究,探讨在中国汉族老年冠心病患者植入药物洗脱支架后,CYP2C19基因681G〉A位点单核苷酸多态性与氯吡格雷抵抗（CR）之间的关系。方法2010年6月至2011年4月,连续入选在沈阳军区总医院心血管内科住院治疗并成功接受经皮冠状动脉药物洗脱支架植入术的老年（年龄≥60岁）冠心病患者614例。所有人选患者全部接受双联抗血小板治疗（氯吡格雷＋阿司匹林）,均给予负荷剂量氯吡格雷600mg及阿司匹林300mg,并于服药24h后采静脉血测定20μmol／L的ADP诱导的残余血小板聚集率（RPA）。定义RPA≥70％为CR,RPA〈70％为氯吡格雷非抵抗（NCR）。使用酚．氯仿法提取全血中白细胞基因组DNA标本,并通过聚合酶链反应．限制性片段长度多态性（PCR-RFLP）方法测定CYP2C19基因681G〉A位点单核苷酸多态类型。结果在所有入选的614例老年冠心病患者中,CR的发生率为20．5％（126例）,NCR为79．5％（488例）。CYP2C19基因681G〉A多态位点的三种基因型（GGGA,AA）的频率,在CR组中分别为32．6％、47．6％和19．8％,在NCR组中分别为47．9％,45．1％和7．0％。其中,AA型纯合子在CR组中的频率显著高于NCR组（OR=3．03,95％CI：1．889-5．784,P=0．003）。A等位基因的携带者较G等位基因携带者更易发生CR（OR=1．85,95％CI：1．392-2．459,P：0．002）。结论在中国汉族老年冠心病患者中,CYP2C19基因681G〉A位点单核苷酸多态性与氯吡格雷抵抗的发生存在相关性,其A等位基因可能是氯吡格雷抵抗的遗传易感因素之一。     

Four polymorphisms of the CAPN 10 gene and their relationship to polycystic ovary syndrome susceptibility: a meta-analysis

Objective To investigate the association between CAPN 10 gene polymorphism and polycystic ovary syndrome (PCOS) susceptibility. Design  Meta‐analysis of published case–control studies of four single nucleotide polymorphisms (SNPs) in CAPN 10 and PCOS susceptibility. Patients Women with PCOS. Measurements Odds ratios (ORs) and 95% confidence intervals (CIs) for heterozygous, homozygous, dominant model, recessive model and allele. Results A total of 11 studies were involved in the meta‐analysis. UCSNP‐63 was significantly associated with PCOS, with homozygous carriers (TT vs CC: OR = 0·64; 95% CI: 0·45–0·90) and recessive model (TT vs CC and CT: OR = 0·64; 95% CI: 0·45–0·90) being protective factors. In addition, UCSNP‐19 was significantly associated with PCOS, with recessive model (ins/ins vs del/del and del/ins: OR = 0·72, 95% CI: 0·59–0·88) and insert allele (ins vs del: OR = 0·85, 95% CI: 0·76–0·96) being protective factors, while heterozygous carriers (del/ins vs del/del: OR = 1·56, 95% CI: 1·24–1·94) and deletion allele (del vs ins: OR = 1·18, 95% CI: 1·04–1·32) being risk factors. However, no significant associations were found between UCSNP‐44, ‐43 and PCOS. Moreover, the results of the Rotterdam criteria subgroup analysis were similar with that of overall analysis. Conclusions This is the first report on the association between CAPN 10 UCSNP‐63 and PCOS in genotype, with homozygous carriers and recessive model being protective factors. Additionally, insert allele and recessive model of UCSNP‐19 are protective factors, while deletion allele and heterozygous genotype are risk factors for PCOS development.     

Drug-Eluting Versus Bare-Metal Stents in Older Patients: A Meta-Analysis of Randomized Controlled Trials

BackgroundDespite the high prevalence of ischemic heart disease in older patients, there is a substantial lack of evidence to guide clinical decision-making in this population. Hence, we performed a meta-analysis to determine the safety and efficacy of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) versus bare-metal stents (BMS).MethodsElectronic databases were searched for randomized trials comparing DES with BMS in patients ≥70 years-old. The primary outcome was major adverse cardiovascular events (MACE). Secondary outcomes included different ischemic and bleeding events. Subgroup analyses for dual-antiplatelet therapy (DAPT) duration were conducted.ResultsWe included 7 trials with a total of 5449 patients. The use of DES compared with BMS was associated with a significant reduction in MACE (odds ratio [OR]:0.76; 95% confidence interval [CI]:0.62–0.93; P = 0.007) with no increased risk of bleeding events (OR: 1.07; 95% CI: 0.89–1.27; P = 0.48). However, longer duration of DAPT (>6 months) for the DES group increased bleeding events (OR: 1.52; 95% CI: 1.05–2.20; P = 0.03). In contrast, shorter DAPT showed persistent efficacy in reducing MACE in DES-treated patients with no increased bleeding events (OR: 0.72; 95% CI: 0.60–0.87; P < 0.01 and OR: 1.01; 95% CI: 0.84–1.22; P = 0.89, respectively).ConclusionsIn older patients who had undergone PCI, DES showed superior efficacy in reducing MACE with no increased risk of bleeding compared with BMS. Persistent MACE reduction was evident with shorter DAPT durations in DES-treated patients.SummaryThis meta-analysis of randomized clinical trials demonstrated that drug-eluting stents were associated with a significant reduction in major adverse cardiovascular events with no increased risk of bleeding compared with bare-metal stents. The risk of bleeding was high with longer dual antiplatelet therapy duration for patients who underwent DES placement. However, short duration of dual antiplatelet therapy substantially reduced major adverse cardiovascular events with no increased bleeding risk.     

Relation of cytochrome P450 2C19 gene 681G&gt;A single nucleotide polynmrphism to clopidogrel resistance after PCI in Chinese

Objectives Clopidogrel is a prodrug that has to be converted to an active metabolite by hepatic cytochrome P450(CYP) isoenzymes to inhibit platelet aggregation.Individualvariability of platelet inhibition by clopidogrel suggests a possibility for genetic factors having a significant influence on clopidogrel responsiveness.In this study,we sought to determine the association between the single nucleotide polymorphism of CYP 2C19 681G>A and the occurrence of clopidogrel resistance(CR) in Chinese.Methods The study enrolled 614 hospitalized patients who underwentsuccessful percutaneouscoronary intervention with drug-eluting stents were received the treatmentwith dual antiplatelet regimen(aspirin plus clopidogrel).All patients received loading doses of 600 mg clopidogrel and 300 mg aspirin.20μmol/L ADP-induced platelet aggregation ratio(PAR ) was assessed 24 h after clopi- dogrel administration.The maximum residual PAR≥70%was defined as CR.Genomic DNA was extracted from whole blood samples according to standard protocols,the single nucleotide polymorphism of the CYP2C19 681G>A was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in all the patients.Results CR was found in 126 patients(20.5%).There was CYP2C19 681G>A polymorphism in the study population.The frequencies of the three kinds of genotypes(GG,GA,A A) in CR group and non-CR (NCR)group were 32.5%,47.6%,19.8%and 48.0%, 45.0%,7.0%,respectively.The frequency of AA genotype was significantly higher in NCR group than that in CR group (OR =3.03,95%CI:1.889～5.784,P=0.003).The A allele carriers were more likely to develop clopidogrel resistance compared with that of G allele carriers(OR=1.85,95%CI: 1.392～2.459,P=0.002).Conclusions CYP2C19 681G/A polymorphism is associated with the risk of CR,and the A allele carriers may be a possible genetic susceptibility factor for patients with CR.     

Clinical importance of thrombocytopenia in patients with acute coronary syndromes: a systematic review and meta-analysis

Thrombocytopenia (TP) is common in hospitalized patients. In the context of acute coronary syndromes (ACS), TP has been linked to adverse clinical outcomes. We present a systematic review and meta-analysis of the evidence on the clinical importance of preexisting and in-hospital acquired TP in the context of ACS. Specifically, we address (a) the prevalence and associated factors with TP in the context of ACS; and (b) the association between TP and all-cause mortality, major adverse cardiovascular events (MACEs), and major bleeding. We conducted systematic literature searches in MEDLINE and Web of Science. For the meta-analysis, we fit linear mixed models with a random study-specific intercept for the aggregate outcomes. A total of 16 studies and 190 915 patients were included in this study. Of these patients, 8.8% ± 1.2% presented with preexisting TP while 5.8% ± 1.0% developed TP after hospital admission. Preexisting TP was not statistically significantly associated with adverse outcomes. Acquired TP was associated with greater risk of all-cause mortality (risk difference [RD]: 4.3%; 95% confidence interval [CI]: 2–6%; p = 0.04), MACE (RD: 8.5%; 95% CI: 1–16.0%; p = 0.037), and major bleeding (RD: 11.9%; 95% CI: 5–19%; p = 0.005). In conclusion, TP is a prevalent condition in patients admitted for an ACS and identifies a high-risk patient population more likely to experience ischemic and bleeding complications, as well as higher mortality.     

Modification of menopausal hormone therapy-associated colorectal cancer risk by polymorphisms in sex steroid signaling, metabolism and transport related genes

The mechanisms underlying the association of menopausal hormone therapy (MHT) with reduced colorectal cancer (CRC) risk are unknown and the identification of genetic modifiers may yield further insight. We explored the effect modification of MHT-associated CRC risk in postmenopausal women by 47 polymorphisms with known or putative functional relevance in 16 candidate genes related to hormone metabolism (COMT, CYP1A1, CYP1A2, CYP1B1, CYP2C9, CYP2C19, CYP3A4, CYP17A1, GSTP, and HSD17B1), transport (ABCB1), and signaling (ESR1, ESR2, SHBG, PGR, and NR1I2). A total of 685 CRC patients and 684 healthy controls from a German population-based case-control study (DACHS) were genotyped. Multiplicative statistical interaction between polymorphisms and ever MHT use as well as duration of use was assessed using multivariate logistic regression. CRC risk associated with ever MHT use as well as with duration was significantly modified by rs1202168 in the transporter gene ABCB1 (P interaction=0.04). The MHT-associated risk reduction was not significant in homozygous non-carriers (odds ratio (OR) ever use=0.84, 95% confidence interval (CI) 0.53-1.34; OR per 5 year duration=0.94, 95% CI 0.83-1.08), while homozygous carriers of the minor T allele had a 57% lower risk with ever use of MHT (95% CI 0.21-0.88) and a 22% lower risk per 5 years of MHT use (95% CI 0.62-0.97). Significant effect modification was also observed for the ESR1_rs910416 polymorphism (P interaction=0.03 for ever use and 0.07 for duration of use), whereby the decreased risk was attenuated in homozygous carriers of the minor C allele (OR ever use=0.87, 95% CI 0.48-1.60, OR per 5 year duration=0.99, 95% CI 0.83-1.18). Results of this exploratory study provide first evidence that polymorphisms in genes related to estrogen transport and signaling may modify MHT-associated CRC risk but warrant replication in an independent population.     

Ticagrelor Versus Clopidogrel as Part of Dual or Triple Antithrombotic Therapy: a Systematic Review and Meta-Analysis

Purpose

Clopidogrel is the standard P2Y₁₂ receptor inhibitor used in patients requiring both antiplatelet therapy and oral anticoagulation (OAC). We investigated the safety and efficacy of ticagrelor as an alternative to clopidogrel in patients on OAC.

Methods

A systematic electronic literature search was performed in MEDLINE, EMBASE, and the Cochrane Library for randomised controlled studies that examined the relative safety and efficacy of clopidogrel versus ticagrelor among patients requiring therapy with antiplatelet agents plus OAC.

Results

Three randomised controlled trials were identified with a total of 5659 patients. The risk of clinically significant bleeding was significantly increased among patients on dual or triple antithrombotic therapy who received ticagrelor compared with patients on clopidogrel (OR 1.52, 95% CI 1.12 to 2.06, and OR 1.7, 95% CI 1.24 to 2.33, respectively). Among those on triple therapy, ticagrelor was associated with a significantly higher risk of major adverse cardiovascular events (MACE) compared to clopidogrel (OR 1.88, 95% CI 1.26 to 2.80). Patients who received dual therapy exhibited similar risk of MACE and stroke with ticagrelor versus clopidogrel (OR 1.14, 95% CI 0.83 to 1.56, and OR 0.42, 95% CI 0.10 to 1.74, respectively).

Conclusion

The use of ticagrelor as part of dual or triple antithrombotic therapy is associated with significantly higher rates of clinically relevant haemorrhagic complications compared with clopidogrel. Among triple therapy-treated patients, the use of ticagrelor might increase thromboembolic and ischaemic cardiac events.

     

Antithrombotic Regimens for Patients Taking Oral Anticoagulation After Coronary Intervention: A Meta‐analysis of 16 Clinical Trials and 9185 Patients

The optimal antithrombotic regimen remains controversial in patients taking oral anticoagulation (OAC) undergoing coronary stenting. This study sought to compare efficacy and safety outcomes of triple therapy (OAC, aspirin, and clopidogrel) vs dual therapy (clopidogrel with aspirin or OAC) in these patients. We hypothesize OAC plus clopidogrel could be the optimal regimen for patients with indications for OAC receiving stent implantation. Medline, the Cochrane Library, and other Internet sources were searched for clinical trials comparing the efficacy and safety of triple vs dual therapy for patients taking OAC after coronary stenting. Sixteen eligible trials including 9185 patients were identified. The risks of major adverse cardiac events (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 0.82‐1.39, P = 0.65), all‐cause mortality (OR: 0.98, 95% CI: 0.76‐1.27, P = 0.89), myocardial infarction (OR: 1.01, 95% CI: 0.77‐1.31, P = 0.97), and stent thrombosis (OR: 0.91, 95% CI: 0.49‐1.69, P = 0.75) were similar between triple and dual therapy. Compared with dual therapy, triple therapy was associated with a reduced risk of ischemic stroke (OR: 0.57, 95% CI: 0.35‐0.94, P = 0.03) but with higher major bleeding (OR: 1.52, 95% CI: 1.11‐2.10, P = 0.01) and minor bleeding (OR: 1.59, 95% CI: 1.05‐2.42, P = 0.03). Subgroup analysis indicated there were similar ischemic stroke and major bleeding outcomes between triple therapy and therapy with OAC plus clopidogrel. Treatment with OAC and clopidogrel was associated with similar efficacy and safety outcomes compared with triple therapy. Triple therapy could be replaced by OAC plus clopidogrel without any concern about additional risk of thrombotic events.