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Background/Objectives: Antiplatelet therapy after emergent carotid stenting (eCAS) represents a challenge in balancing the risk of intracerebral hemorrhages (ICHs) and in-stent thrombosis (IST). Post-procedural platelet function monitoring may guide antiplatelet therapy and could potentially improve outcomes due to fewer post-procedural complications. Methods: Consecutive eCAS patients (2019–2021) were included in a single-center retrospective observational study. Patients treated with eCAS received peri-procedural eptifibatide followed by dual antiplatelet treatment with aspirin and clopidogrel. The effect of platelet ADP inhibition by clopidogrel was monitored using the Multiplate® Analyzer (Roche). Clopidogrel non-responders were changed to ticagrelor treatment. The primary outcome was defined as a favorable outcome at 90 days using the modified Rankin Scale (mRS) of 0–2 versus 3–6. Safety outcomes included ICH, IST, and mortality. Data were analyzed and compared in clopidogrel- and ticagrelor-treated patients using Fischer's exact test and multivariate logistic regression. Results: A total of 105 patients had eCAS, and 28 patients (27%) were clopidogrel non-responders and were changed to treatment with ticagrelor. The favorable outcome was more frequent in ticagrelor-treated patients, 23 (82%), than in clopidogrel-treated patients, 44 (57%), p = 0.036. Numerically, ICH, IST, and mortality were more frequent in clopidogrel-treated patients, but none of the differences were statistically significant. In multivariate analyses, ticagrelor treatment was significantly associated with the favorable outcome, OR = 3.89 (95% CI: 1.09–13.86), p = 0.036. Conclusions: One in four eCAS patients were clopidogrel non-responders. This study suggests that personalized antiplatelet treatment therapy was safe, and that changing treatment to ticagrelor in clopidogrel non-responders was associated with better outcomes in eCAS patients. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Cats with cardiomyopathy face an increased risk of arterial thromboembolism (ATE). Although clopidogrel is frequently utilized to mitigate this risk, feline responses to this therapy exhibit variability. This study evaluated 2 viscoelastic devices, thromboelastography (TEG) and Viscoelastic Coagulation Monitor (VCM), for monitoring clopidogrel in cats in comparison to light transmission aggregometry (LTA). METHODS: Twenty-eight healthy cats received clopidogrel for 7 days. Blood was collected at baseline and after treatment for analysis by TEG, VCM, and LTA. RESULTS: On LTA, maximum amplitude, slope, and area under the curve (AUC) significantly decreased after treatment (p

Stroke remained the second leading cause of death globally in 2019. The antiplatelet drug clopidogrel is used to keep blood clots from forming in people who have experienced a stroke. Although most people find clopidogrel to be safe and beneficial, there is inevitably a range in how each patient responds. The review covers about Clopidogrel resistance in stroke patients, their risk factors and the methods to identify it. Clopidogrel resistance is characterized as the drug’s inability to prevent the target enzyme from acting. The prognosis of patients with ischemic stroke and the responsiveness to clopidogrel are significantly impacted by the various genetic polymorphism CYP2C19 genotypes. The two primary mutant alleles, CYP2C19 *2 and CYP2C19 *3, have been found to be the most prevalent genotypes. Better mRS scores six months after treatment showed a higher response rate in patients without these CYP2C19 variant alleles. Other factors are drug-drug interaction (proton pump inhibitors), demographics (age, sex, social history), comorbid conditions, etc. Blood samples for testing platelet reactivity were drawn one month after discharge from a peripheral blood sample. Several methods are used to identify the clopidogrel resistance. Some of them are ADP-Induced platelet aggregation, Platelet Reactivity Index VASP, Verify Now Assay, TEG Analyzer, Plasma microRNA-223. Drugs that are not prodrugs and whose metabolism is not dependent upon CYP2C19 can be selected as a superior alternative in case of CR. Ticagrelor is one such effective substitute. Proton pump inhibitors and clopidogrel should only be used concurrently in patients with reliable clinical indications.

Stroke remained the second leading cause of death globally in 2019. The antiplatelet drug clopidogrel is used to keep blood clots from forming in people who have experienced a stroke. Although most people find clopidogrel to be safe and beneficial, there is inevitably a range in how each patient responds.The review covers about Clopidogrel resistance in stroke patients, their risk factors and the methods to identify it. Clopidogrel resistance is characterized as the drug's inability to prevent the target enzyme from acting. The prognosis of patients with ischemic stroke and the responsiveness to clopidogrel are significantly impacted by the various genetic polymorphism CYP2C19 genotypes. The two primary mutant alleles, CYP2C19 *2 and CYP2C19 *3, have been found to be the most prevalent genotypes. Better mRS scores six months after treatment showed a higher response rate in patients without these CYP2C19 variant alleles. Other factors are drug-drug interaction (proton pump inhibitors), demographics (age, sex, social history), comorbid conditions, etc. Blood samples for testing platelet reactivity were drawn one month after discharge from a peripheral blood sample. Several methods are used to identify the clopidogrel resistance. Some of them are ADP-Induced platelet aggregation, Platelet Reactivity Index VASP, Verify Now Assay, TEG Analyzer, Plasma microRNA-223. Drugs that are not prodrugs and whose metabolism is not dependent upon CYP2C19 can be selected as a superior alternative in case of CR. Ticagrelor is one such effective substitute. Proton pump inhibitors and clopidogrel should only be used concurrently in patients with reliable clinical indications. [ABSTRACT FROM AUTHOR]

The management of antiplatelet medications in neurointerventional procedures remains a subject of considerable variability and debate. This review article explores the diverse clinical practices and the impact of different antiplatelet regimens and platelet activity testing on patient outcomes in neurointerventional treatments. While much of the evidence around antiplatelet therapies largely stems from randomized trials in cardiac and peripheral vascular diseases, their application in neurointerventional settings requires nuanced consideration. Various assays exist to assess individual platelet function, yet the optimal assay, thresholds, and agents remain uncertain due to interpatient variability in medication responsiveness. Expert consensus groups have attempted to standardize antiplatelet management, which is summarized for elective and emergent neurointerventional procedures. Clopidogrel, a commonly used antiplatelet, faces challenges such as genetic variability in metabolism and drug–drug interactions, impacting its effectiveness. Other agents, such as ticagrelor and prasugrel, offer alternatives with different mechanisms of action and potential advantages. Additionally, short‐acting intravenous P2Y12 inhibitors, such as cangrelor, and glycoprotein IIb/IIIa inhibitors provide options for acute bridging therapy in neurointerventional cases. Despite advancements, significant gaps persist in understanding the optimal antiplatelet management for neurovascular procedures. While platelet function testing is commonly used, its clinical utility and standardization remain an area of investigation. This review underscores the need for further multicenter studies to delineate best practices and optimize patient outcomes in neurointerventional settings.

BackgroundDual antithrombotic treatment (DAT) with clopidogrel and rivaroxaban sometimes is prescribed to cats with hypertrophic cardiomyopathy at risk of thromboembolism. To date, no studies have evaluated their combined effects on platelet function.Objectives/hypothesisEvaluate the safety of DAT in healthy cats and compare, ex vivo, platelet-dependent thrombin generation and agonist-induced platelet activation and aggregation in cats treated with clopidogrel, rivaroxaban, or DAT. We hypothesized that DAT would safely modulate agonist-induced platelet activation and aggregation more effectively than single agent treatment.AnimalsNine apparently healthy 1-year-old cats selected from a research colony.MethodsUnblinded, nonrandomized ex vivo cross-over study. All cats received 7 days of rivaroxaban (0.6 ± 0.1 mg/kg PO), clopidogrel (4.7 ± 0.8 mg/kg PO), or DAT with defined washout periods between treatments. Before and after each treatment, adenosine diphosphate (ADP)- and thrombin-induced platelet P-selectin expression was evaluated using flow cytometry to assess platelet activation. Platelet-dependent thrombin generation was measured by fluorescence assay. Platelet aggregation was assessed using whole blood impedance platelet aggregometry.ResultsNo cats exhibited adverse effects. Of the 3 treatments, only DAT significantly decreased the number of activated platelets (P = .002), modulated platelet activation in response to thrombin (P = .01), dampened thrombin generation potential (P = .01), and delayed maximum reaction velocity (P = .004) in thrombin generation. Like clopidogrel, DAT inhibited ADP-mediated platelet aggregation. However, rivaroxaban alone resulted in increased aggregation and activation in response to ADP.Conclusion and clinical importanceTreatment combining clopidogrel and rivaroxaban (DAT) safely decreases platelet activation, platelet response to agonists, and thrombin generation in feline platelets more effectively than monotherapy with either clopidogrel or rivaroxaban.

Abstract Background Mediators, genomic and epigenomic characteristics involving in metabolism of arachidonic acid by cyclooxygenase (COX) and lipoxygenase (ALOX) and hepatic activation of clopidogrel have been individually suggested as factors associated with resistance against aspirin and clopidogrel. The present multi-center prospective cohort study evaluated whether the mediators, genomic and epigenomic characteristics participating in arachidonic acid metabolism and clopidogrel activation could be factors that improve the prediction of the aspirin and clopidogrel resistance in addition to cardiovascular risks. Methods We enrolled 988 patients with transient ischemic attack and ischemic stroke who were evaluated for a recurrence of ischemic stroke to confirm clinical resistance, and measured aspirin (ARU) and P2Y12 reaction units (PRU) using VerifyNow to assess laboratory resistance 12 weeks after aspirin and clopidogrel administration. We investigated whether mediators, genotypes, and promoter methylation of genes involved in COX and ALOX metabolisms and clopidogrel activation could synergistically improve the prediction of ischemic stroke recurrence and the ARU and PRU levels by integrating to the established cardiovascular risk factors. Results The logistic model to predict the recurrence used thromboxane A synthase 1 (TXAS1, rs41708) A/A genotype and ALOX12 promoter methylation as independent variables, and, improved sensitivity of recurrence prediction from 3.4% before to 13.8% after adding the mediators, genomic and epigenomic variables to the cardiovascular risks. The linear model we used to predict the ARU level included leukotriene B4, COX2 (rs20417) C/G and thromboxane A2 receptor (rs1131882) A/A genotypes with the addition of COX1 and ALOX15 promoter methylations as variables. The linear PRU prediction model included G/A and prostaglandin I receptor (rs4987262) G/A genotypes, COX2 and TXAS1 promoter methylation, as well as cytochrome P450 2C19*2 (rs4244285) A/A, G/A, and *3 (rs4986893) A/A genotypes as variables. The linear models for predicting ARU (r = 0.291, R2 = 0.033, p

Background: Mediators, genomic and epigenomic characteristics involving in metabolism of arachidonic acid by cyclooxygenase (COX) and lipoxygenase (ALOX) and hepatic activation of clopidogrel have been individually suggested as factors associated with resistance against aspirin and clopidogrel. The present multi-center prospective cohort study evaluated whether the mediators, genomic and epigenomic characteristics participating in arachidonic acid metabolism and clopidogrel activation could be factors that improve the prediction of the aspirin and clopidogrel resistance in addition to cardiovascular risks. Methods: We enrolled 988 patients with transient ischemic attack and ischemic stroke who were evaluated for a recurrence of ischemic stroke to confirm clinical resistance, and measured aspirin (ARU) and P2Y12 reaction units (PRU) using VerifyNow to assess laboratory resistance 12 weeks after aspirin and clopidogrel administration. We investigated whether mediators, genotypes, and promoter methylation of genes involved in COX and ALOX metabolisms and clopidogrel activation could synergistically improve the prediction of ischemic stroke recurrence and the ARU and PRU levels by integrating to the established cardiovascular risk factors. Results: The logistic model to predict the recurrence used thromboxane A synthase 1 (TXAS1, rs41708) A/A genotype and ALOX12 promoter methylation as independent variables, and, improved sensitivity of recurrence prediction from 3.4% before to 13.8% after adding the mediators, genomic and epigenomic variables to the cardiovascular risks. The linear model we used to predict the ARU level included leukotriene B4, COX2 (rs20417) C/G and thromboxane A2 receptor (rs1131882) A/A genotypes with the addition of COX1 and ALOX15 promoter methylations as variables. The linear PRU prediction model included G/A and prostaglandin I receptor (rs4987262) G/A genotypes, COX2 and TXAS1 promoter methylation, as well as cytochrome P450 2C19*2 (rs4244285) A/A, G/A, and *3 (rs4986893) A/A genotypes as variables. The linear models for predicting ARU (r = 0.291, R2 = 0.033, p < 0.01) and PRU (r = 0.503, R2 = 0.210, p < 0.001) levels had improved prediction performance after adding the genomic and epigenomic variables to the cardiovascular risks. Conclusions: This study demonstrates that different mediators, genomic and epigenomic characteristics of arachidonic acid metabolism and clopidogrel activation synergistically improved the prediction of the aspirin and clopidogrel resistance together with the cardiovascular risk factors. Trial registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03823274. [ABSTRACT FROM AUTHOR]

Objective: Current guidelines recommend dual antiplatelet therapy (DAPT) in patients undergoing carotid artery stenting. The most common DAPT regimen is aspirin and clopidogrel, a P2Y12 receptor antagonist; however, the prevalence of clopidogrel resistance (CR) in patients undergoing percutaneous coronary interventions may exceed 60%. Few studies have investigated the prevalence and impact of CR in patients undergoing extracranial carotid artery stenting, particularly transcarotid artery revascularization (TCAR). Methods: Consecutive high-risk patients ≥ 18 years who underwent TCAR for high grade (≥70%) and/or symptomatic (≥50%) carotid stenosis with preoperative P2Y12 testing between August 2019 and December 2021 were identified across five institutions. Preoperative platelet reactivity was measured with the VerifyNow P2Y12 Reaction Unit (PRU) Test (Instrumentation Laboratory, Bedford, MA), with CR defined as PRU ≥ 194 and hyper-response as PRU <70. Patients without preoperative P2Y12 testing within 30 days prior to TCAR or those on a non-clopidogrel P2Y12 inhibitor preoperatively were excluded. The primary outcome of interest was prevalence of CR. Secondary outcomes of interest included the incidence of ischemic and hemorrhagic complications. Results: Of 92 patients identified, the majority were male (59%) and Caucasian (75%) with a mean age of 75 years (±8, range 56 – 92). Preoperatively, 93% of patients were on aspirin, 100% on clopidogrel, and 13% on therapeutic anticoagulation. At presentation, 36% were symptomatic. The mean preoperative P2Y12 was 156 PRU (±76, range 6 – 349). In total, 30 (33%) patients met criteria for CR (mean PRU 240 ± 37; range 197–349), and 15 (16%) met criteria for hyper-responder (mean PRU 38 ± 20; range 6–68). There was no significant difference by clopidogrel response phenotype in terms of sex (p = 0.246), race (p = 0.384), or symptomatic presentation (p = 0.956). Postoperatively, the cumulative incidence of stroke and MI was 2.1%, with no statistically significant difference in the incidence of in-hospital stroke (PRU 238, p = 0.489) or MI (PRU 168, p = 1) between clopidogrel phenotypes. Three (3.3%) patients, one CR (PRU 240) and two responders (PRU 119 and PRU 189), experienced postoperative access site hematomas that required no subsequent intervention. No other index hospitalization hemorrhagic complications occurred. Conclusions: Using preoperative P2Y12 testing with a threshold PRU ≥ 194 to define CR, we identified a high prevalence of CR in patients undergoing TCAR similar to that in the pre-existing coronary literature. We found no significant differences in postoperative ischemic or hemorrhagic complications by clopidogrel response phenotype, although complication rates in the overall study cohort were low. CR may be a spectrum from responder to partial responder to complete non-responder, and this may account for the differences in our CR cohort compared to the ROADSTER 2 protocol deviation cohort. Further investigation is warranted to determine if a quantitative assessment of CR is sufficient to identify patients at risk of developing secondary cerebrovascular ischemic events in this patient population. [ABSTRACT FROM AUTHOR]

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Aim: The genetic polymorphism of CYP2C19 influences clopidogrel metabolism and resistance. Aim was to assess the association between CYP2C19 loss of function variation, clopidogrel resistance based on platelet reactivity units and clinical outcomes. Methods: A total of 668 patients of Acute Coronary Sundrome (ACS) who underwent Percutaneous Coronary Intervention (PCI) were subjected to genetic screening and 143 patients undrewent platelet function test to study the association between drug metabolization and its effects based on platelet reactivity unit values. Results: Clopidogrel resistance with CYP2C 19 loss of function variation was noted in 54.64% of patients. Clinical outcomes, such as target vessel revascularization, target lesion revascularization, in-stent restenosis, and stent thrombosis, were also studied. Conclusion: CYP2C19 loss of function variation is strongly associated with clopidogrel resistance and adverse clinical outcomes.

Dual antiplatelet therapy (DAPT) is standard treatment for endoluminal stent insertion, and complete resistance to DAPT is rare. A case of in-stent thrombosis occurring 3 hours after stent-assisted coiling of internal carotid artery aneurysm is presented despite compliance with DAPT. Platelet function tests (PFTs) revealed complete clopidogrel and prasugrel resistance. [ABSTRACT FROM AUTHOR]

Peripheral arterial disease (PAD) affects approximately 236 million people worldwide. Therefore, this study aimed to investigate the relationship between CYP2C19 genotype polymorphisms and clopidogrel resistance (CR) following revascularization in patients with PAD. In total, 345 patients who underwent PAD revascularization were monitored for five years and risk factors for ischemic events were identified. Platelet reactivity and CYP2C19 genotypes were measured, and patients were classified as normal, intermediate, or poor metabolizers based on their genotypes. The study endpoint was defined as an ischemic event, that encompassed major adverse cardiovascular or limb events, or all-cause death. In this study, ischemic events following PAD revascularization were associated with patient age, prior minor amputation, the Rutherford category before revascularization, indications for revascularization, index ankle-branchial index before revascularization, CYP2C19 phenotypes, and CR. Intermediate and poor metabolism, the Rutherford category before revascularization, and CR were independent risk factors for ischemic events in patients after PAD revascularization. Similarly, intermediate and poor metabolism, the Rutherford category before revascularization, and CR were independent risk factors for ischemic events in patients with PAD after revascularization within five years. Intermediate and poor metabolizers had a higher platelet reactivity and risk of CR than normal metabolizers. However, poor metabolizers had a higher platelet reactivity and risk of CR than intermediate metabolizers. Furthermore, the hazard ratio for ischemic events increased with platelet reactivity. This effect was more prevalent in intermediate and poor metabolizers than in normal metabolizers. Ischemic events in patients after PAD revascularization were affected by independent risk factors. Decreased clopidogrel metabolism increased the platelet reactivity and CR in patients after PAD revascularization. Furthermore, high platelet reactivity was associated with an increased risk of ischemic events in patients with intermediate and poor metabolism. [Display omitted] • CYP2C19 phenotype and CR effects after revascularization for PAD remain unclear. • We evaluated these effects on ischemic events after revascularization over 5 years. • CYP2C19 phenotype and CR were independent risk factors for ischemic events. • Patients with impaired clopidogrel metabolism had a higher risk of CR. [ABSTRACT FROM AUTHOR]

Introduction: Trinidad & Tobago has the highest prevalence of cardiovascular disease (CVD) in the Caribbean and clopidogrel is a ubiquitously used treatment. Yet, the extent of genetically mediated clopidogrel resistance is unknown. To determine this, we investigated whether the association between CYP2C19*2 and CYP2C19*3 genetic variants and clopidogrel resistance holds, and calculated the frequencies of these in the Trinidadian CVD population. Methods: Demographic data, clinical data, and a saliva sample were collected under informed consent from 22 patients with CVD on dual anti-platelet therapy whose biochemical resistance to clopidogrel is known, and a further 162 patients accessing the main public CVD clinic in Trinidad and who are either currently being treated or are likely to be treated with clopidogrel. A polymerase chain reaction (PCR) and restriction enzyme digestion procedure was used to genotype each patient for the CYP2C19*2 and CYP2C19*3 allelic variants. Genotype was compared to known clopidogrel resistance in the 22 patients, and to disease status and clopidogrel usage in the larger cohort. Results: CYP2C19*2 genotype was concordant with clopidogrel resistance. CYP2C19*2 was detected in 61.1% (99/162) of patients and CYP2C19*3 was undetected. Clopidogrel was the most prescribed antiplatelet therapy (42%). A total of 120 people presented with coronary artery disease (CAD) and 52.5% of these (n = 63/120) are currently prescribed clopidogrel. 63.5% (40/63) of patients with CAD who are prescribed clopidogrel carry the CYP2C19*2 allele; ten homozygous and 30 heterozygous. Indian patients comprised 65% of the cohort and were four times more likely to carry the CYP2C19*2 allele than African patients. Conclusions: A large proportion of Trinidadian patients with CVD who are prescribed or may be prescribed clopidogrel carry genetic variants associated with clopidogrel resistance. These results emphasize the clinical need for further investigation into whether CYP2C19*2 genotype should guide clopidogrel use for the cardiovascular disease population in Trinidad & Tobago. A slide deck is available for this article. [ABSTRACT FROM AUTHOR]

IntroductionCats with cardiomyopathy face an increased risk of arterial thromboembolism (ATE). Although clopidogrel is frequently utilized to mitigate this risk, feline responses to this therapy exhibit variability. This study evaluated 2 viscoelastic devices, thromboelastography (TEG) and Viscoelastic Coagulation Monitor (VCM), for monitoring clopidogrel in cats in comparison to light transmission aggregometry (LTA).MethodsTwenty-eight healthy cats received clopidogrel for 7 days. Blood was collected at baseline and after treatment for analysis by TEG, VCM, and LTA.ResultsOn LTA, maximum amplitude, slope, and area under the curve (AUC) significantly decreased after treatment (p

Abstract Background Clopidogrel resistance profoundly increases the risk of major cardiovascular events in coronary artery disease (CAD) patients. Here, we comprehensively analyse global m6A modification alterations in clopidogrel-resistant (CR) and non-CR patients. Methods After RNA isolation, the RNA transcriptome expression (lncRNA, circRNA, and mRNA) was analysed via RNA-seq, and m6A peaks were identified by MeRIP-seq. The altered m6A methylation sites on mRNAs, lncRNAs, and circRNAs were identified, and then, GO and KEGG pathway analyses were performed. Through joint analysis with RNA-seq and MeRIP-seq data, differentially expressed mRNAs harbouring differentially methylated sites were identified. The changes in m6A regulator levels and the abundance of differentially methylated sites were measured by RT-PCR. The identification of m6A-modified RNAs was verified by m6A-IP-qPCR. Results The expression of 2919 hypermethylated and 2519 hypomethylated mRNAs, 192 hypermethylated and 391 hypomethylated lncRNAs, and 375 hypermethylated and 546 hypomethylated circRNAs was shown to be altered in CR patients. The m6A peaks related to CR indicated lower mark density at the CDS region. Functional enrichment analysis revealed that inflammatory pathways and insulin signalling pathways might be involved in the pathological processes underlying CR. The expression of mRNAs (ST5, KDM6B, GLB1L2, and LSM14B), lncRNAs (MSTRG.13776.1 and ENST00000627981.1), and circRNAs (hsa_circ_0070675_CBC1, hsa-circRNA13011-5_CBC1, and hsa-circRNA6406-3_CBC1) was upregulated in CR patients, while the expression of mRNAs (RPS16 and CREG1), lncRNAs (MSTRG.9215.1), and circRNAs (hsa_circ_0082972_CBC1) was downregulated in CR patients. Moreover, m6A regulators (FTO, YTHDF3, and WTAP) were also differentially expressed. An additional combined analysis of gene expression and m6A peaks revealed that the expression of mRNAs (such as ST5, LYPD2, and RPS16 mRNAs) was significantly altered in the CR patients. Conclusion The expression of m6A regulators, the RNA transcriptome, and the m6A landscape was altered in CR patients. These findings reveal epitranscriptomic regulation in CR patients, which might be novel therapeutic targets in future.

Ismail Mouhrach,1,2 Laila Bouguenouch,2,3 Adil Kamal,3,4 Abbassi Meriame,2 Nada El Khorb,3,4 Mohammed El Azami El Idrissi,3 Hafid Akoudad,3,4 Hicham Bekkari1 1Laboratory of Biotechnology, Environment, Agrifood, and Health, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, Fez, Morocco; 2Department of Medical Genetics and Oncogenetics, University Hospital Hassan II, Fez, Morocco; 3Faculty of Medicine and Pharmacy, Sidi Mohamed Ben Abdellah University, Fez, Morocco; 4Department of Cardiology, University Hospital Hassan II, Fez, MoroccoCorrespondence: Ismail Mouhrach, Laboratory of Biotechnology, Environment, Agrifood, and Health, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, B.P. 1796 Fès-Atlas, Fez, 30003, Morocco, Tel +212 7 08 02 96 10, Fax +212535642500, Email ismail.mouhrach@usmba.ac.maIntroduction: Clopidogrel is an antiplatelet prodrug primarily prescribed to prevent or treat acute coronary syndrome (ACS) or acute ischemic stroke (IS), polymorphisms of genes encoding cytochrome P-450 (CYP) and P-glycoprotein transporter, could affect the efficiency of clopidogrel absorption and biotransformation, especially during the first critical hours following its administration.Methods: The present study was designed to investigate the potential association of clopidogrel responsiveness and 14 polymorphisms in the genes encoding the CYPs (CYP2C9, 2C19, 3A4, 3A5, 1A2, and 2B6), the ATP binding cassette subfamily B member 1 (ABCB1). Platelet aggregation activity was measured after 8h of 300mg clopidogrel administration for fifty-five ACS patients.Results: There was no significant association between polymorphism of the studied CYPs and clopidogrel responsiveness (P> 0.05). The frequency of the ABCB1 3435 T allele in clopidogrel non-responders was higher (78.9%) compared to responders (52.8%), but this difference was not significant (P=0.057). Demographic characteristics, comorbidities, concomitant treatments were not associated with clopidogrel response.Discussion: There was no effect of the studied genetic variations and demographic factors on the platelet activity of clopidogrel in Moroccan ACS patients.Keywords: clopidogrel resistance, coronary artery disease, gene polymorphisms, platelet inhibitors, ABCB1 gene, CYP450 gene

Abstract Background Stent thrombosis, a life-threatening complication of percutaneous coronary intervention (PCI) continues to occur despite effective antiplatelet regimens and improved stenting methods. Noncompliance with dual antiplatelet therapy is the most common etiology; however, in spite of timely and their optimum administration the rates of recurrent myocardial infarction (MI) and stent thrombosis remain high. Clopidogrel resistance is increasingly evoked with elevated risk of anterothrombotic events particularly in the setting of stent implantation. In this case report, we present a case of subacute stent thrombosis associated with clopidogrel resistance in a resource-constrained setting. Case presentation A 60 year old man with a long standing history of hypertension presented with a 6-month history of progressive shortness of breath. Initial electrocardiogram (ECG) revealed T-wave inversion on lateral leads and echocardiogram revealed akinetic basal lateral wall and hypokinetic mid lateral wall with reduced systolic functions. An elective coronary angiography (CAG) revealed a 90% stenosis of mid left anterior descending (LAD) artery and an 80% stenosis on the proximal left circumflex artery. He underwent a successful PCI with a drug-eluting stent implantation to mid LAD. He was discharged in a stable state 48 h post revascularization with dual antiplatelet (clopidogrel and acetylsalicylic acid). Seven days later, he presented with a crushing substernal chest pain. Cardiac enzymes were elevated and ECG revealed anterior ST-elevation MI. An emergency CAG revealed a high thrombus burden with 100% occlusion of mid LAD. Following unsuccessful ballooning, intravenous and intracoronary thrombolysis with tenecteplase was given. A TIMI II flow was achieved and the patient was sent to the coronary care unit. However, 14 h later there was yet a new onset of severe chest pain. A 12-lead ECG previewed anterior ST-elevation MI and the cardiac enzymes were high. Urgent CAG revealed in-stent thrombotic total occlusion of mid LAD. A stent in stent was then implanted and TIMI III flow was restored. Clopidogrel resistance was suspected and the patient was transitioned to ticagrelol. There were no further ischemic events during the remainder of hospitalization and the patient was discharged in a hemodynamically stable state three days later. During follow-up after one and three months, he was fairly stable without any further cardiac events. Conclusions Owing to clopidogrel resistance, stent thrombosis in the setting of dual antiplatelet therapy compliance may occur. While in a situation of clopidogrel resistance newer and more potent antiplatelet drugs should be used, their availability and cost remains a significant barrier particularly in the developing world. Nonetheless, a high index of suspicion and timely revascularization is fundamental to restore patency of the thrombosed vessel and confer better risk-adjusted survival rates.

Abstract Introduction Clopidogrel is recommended as an alternative to Acetyl Salicylic Acid (ASA), the first-line drug for secondary stroke prevention. Clopidogrel resistance in Indonesia is reportedly 15.8%. The Stent Thrombosis in Belgium (STIB) is a scoring system proposed to assess clopidogrel resistance which has not been tested for the reliability in Indonesian population. Objectives The objective of the study is to test the reliability of the STIB scoring and modified-STIB scoring system in Indonesian population. Methods This study was conducted cross-sectionally in Dr. Cipto Mangunkusumo Hospital and Universitas Indonesia Hospital from January 2020 to December 2021. Laboratory examinations of human CYP450 concentration in blood plasma from 112 subjects were carried out using the ELISA method. The clopidogrel resistance test was carried out using the VerifyNow method. Results Out of 112 ischemic stroke patients in this study, 14.3% of them did not respond to clopidogrel. Cross-tabulation between the STIB score and clopidogrel resistance showed significant results (p

N6-methyladenosine (m6A) is the most frequently occurring interior modification in eukaryotic messenger RNA (mRNA), and abnormal mRNA modifications can affect many biological processes. However, m6A’s effect on the metabolism of antiplatelet drugs for the prevention of ischemic stroke (IS) remains largely unclear.

Objective To investigate the risk factors of drug resistance in patients with ischemic stroke by clopidogrel therapy and provide references for promoting clinical individualized drug therapy. Methods A total of 202 inpatients diagnosed with ischemic stroke were admitted and given dual anti-treatment (aspirin+clopidogrel). CYP2C19 genotype was detected by microarray hybridization during hospitalization, and CYP2C19 gene polymorphisms were classified into fast metabolism group, medium metabolism group and slow metabolism group according to the type of drug metabolism. Patients were tested for platelet inhibition induced by adenosine diphosphate (ADP) according to thromboelastographic (TEG) on 7～14 d of drug administration. ADP <30% was classified as clopidogrel drug resistance group and ADP ≥30% as non-resistance group. Logistic regression analysis was used to study the risk factors for the development of clopidogrel resistance. Results Among 202 patients with ischemic stroke, 87 were in the resistant group and 115 in the non-resistant group. The proportion of patients with clopidogrel resistance combined with diabetes and the level of white blood cell count were higher than that in the non-resistant group, and the differences were statistically significant (P<0.05). The proportion of patients with clopidogrel resistance in the CYP2C19 intermediate metabolism group was significantly higher than that in the fast metabolism group, and the rate of platelet inhibition was also significantly lower than that in the fast metabolism group, all with statistically significant differences (P<0.05). Conclusion Combined diabetes mellitus, high white blood cell count levels and CYP2C19 mid-metabolic phenotype are independent risk factors for the development of clopidogrel resistance in patients with ischemic stroke. [ABSTRACT FROM AUTHOR]

Background ‒ N6-methyladenosine (m6 A) is the most frequently occurring interior modification in eukaryotic messenger RNA (mRNA), and abnormal mRNA modifications can affect many biological processes. However, m6 A’s effect on the metabolism of antiplatelet drugs for the prevention of ischemic stroke (IS) remains largely unclear. Methods ‒ We analyzed the m6 A enzymes and m6 A methylation in peripheral blood samples of IS patients with/without clopidogrel resistance (CR), and the peripheral blood and liver of rat models with/without CR. We also compared the effect of m6 A methylation on the expression of the drug-metabolizing enzymes (CYP2C19 and CYP2C6v1) in CR and non-CR samples. Results ‒ Methyltransferase-like 3 (METTL3), an m6 A enzyme, was highly expressed in the peripheral blood of patients with CR, and in both the peripheral blood and liver of rats with CR. This enzyme targets CYP2C19 or CYP2C6v1 mRNA through m6 A methylation, resulting in low expression of CYP2C19 or CYP2C6v1 mRNA. Consequently, this leads to decreased clopidogrel metabolism and CR. Conclusion ‒ The METTL3-mediated methylation of CYP2C19 mRNA may aggravate CR in IS patients. [ABSTRACT FROM AUTHOR]

Background: Clopidogrel resistance profoundly increases the risk of major cardiovascular events in coronary artery disease (CAD) patients. Here, we comprehensively analyse global m6A modification alterations in clopidogrel-resistant (CR) and non-CR patients. Methods: After RNA isolation, the RNA transcriptome expression (lncRNA, circRNA, and mRNA) was analysed via RNA-seq, and m6A peaks were identified by MeRIP-seq. The altered m6A methylation sites on mRNAs, lncRNAs, and circRNAs were identified, and then, GO and KEGG pathway analyses were performed. Through joint analysis with RNA-seq and MeRIP-seq data, differentially expressed mRNAs harbouring differentially methylated sites were identified. The changes in m6A regulator levels and the abundance of differentially methylated sites were measured by RT-PCR. The identification of m6A-modified RNAs was verified by m6A-IP-qPCR. Results: The expression of 2919 hypermethylated and 2519 hypomethylated mRNAs, 192 hypermethylated and 391 hypomethylated lncRNAs, and 375 hypermethylated and 546 hypomethylated circRNAs was shown to be altered in CR patients. The m6A peaks related to CR indicated lower mark density at the CDS region. Functional enrichment analysis revealed that inflammatory pathways and insulin signalling pathways might be involved in the pathological processes underlying CR. The expression of mRNAs (ST5, KDM6B, GLB1L2, and LSM14B), lncRNAs (MSTRG.13776.1 and ENST00000627981.1), and circRNAs (hsa_circ_0070675_CBC1, hsa-circRNA13011-5_CBC1, and hsa-circRNA6406-3_CBC1) was upregulated in CR patients, while the expression of mRNAs (RPS16 and CREG1), lncRNAs (MSTRG.9215.1), and circRNAs (hsa_circ_0082972_CBC1) was downregulated in CR patients. Moreover, m6A regulators (FTO, YTHDF3, and WTAP) were also differentially expressed. An additional combined analysis of gene expression and m6A peaks revealed that the expression of mRNAs (such as ST5, LYPD2, and RPS16 mRNAs) was significantly altered in the CR patients. Conclusion: The expression of m6A regulators, the RNA transcriptome, and the m6A landscape was altered in CR patients. These findings reveal epitranscriptomic regulation in CR patients, which might be novel therapeutic targets in future. [ABSTRACT FROM AUTHOR]

Abstract Background Dual antithrombotic treatment (DAT) with clopidogrel and rivaroxaban sometimes is prescribed to cats with hypertrophic cardiomyopathy at risk of thromboembolism. To date, no studies have evaluated their combined effects on platelet function. Objectives/Hypothesis Evaluate the safety of DAT in healthy cats and compare, ex vivo, platelet‐dependent thrombin generation and agonist‐induced platelet activation and aggregation in cats treated with clopidogrel, rivaroxaban, or DAT. We hypothesized that DAT would safely modulate agonist‐induced platelet activation and aggregation more effectively than single agent treatment. Animals Nine apparently healthy 1‐year‐old cats selected from a research colony. Methods Unblinded, nonrandomized ex vivo cross‐over study. All cats received 7 days of rivaroxaban (0.6 ± 0.1 mg/kg PO), clopidogrel (4.7 ± 0.8 mg/kg PO), or DAT with defined washout periods between treatments. Before and after each treatment, adenosine diphosphate (ADP)‐ and thrombin‐induced platelet P‐selectin expression was evaluated using flow cytometry to assess platelet activation. Platelet‐dependent thrombin generation was measured by fluorescence assay. Platelet aggregation was assessed using whole blood impedance platelet aggregometry. Results No cats exhibited adverse effects. Of the 3 treatments, only DAT significantly decreased the number of activated platelets (P = .002), modulated platelet activation in response to thrombin (P = .01), dampened thrombin generation potential (P = .01), and delayed maximum reaction velocity (P = .004) in thrombin generation. Like clopidogrel, DAT inhibited ADP‐mediated platelet aggregation. However, rivaroxaban alone resulted in increased aggregation and activation in response to ADP. Conclusion and Clinical Importance Treatment combining clopidogrel and rivaroxaban (DAT) safely decreases platelet activation, platelet response to agonists, and thrombin generation in feline platelets more effectively than monotherapy with either clopidogrel or rivaroxaban.

Background: Stent thrombosis, a life-threatening complication of percutaneous coronary intervention (PCI) continues to occur despite effective antiplatelet regimens and improved stenting methods. Noncompliance with dual antiplatelet therapy is the most common etiology; however, in spite of timely and their optimum administration the rates of recurrent myocardial infarction (MI) and stent thrombosis remain high. Clopidogrel resistance is increasingly evoked with elevated risk of anterothrombotic events particularly in the setting of stent implantation. In this case report, we present a case of subacute stent thrombosis associated with clopidogrel resistance in a resource-constrained setting. Case presentation: A 60 year old man with a long standing history of hypertension presented with a 6-month history of progressive shortness of breath. Initial electrocardiogram (ECG) revealed T-wave inversion on lateral leads and echocardiogram revealed akinetic basal lateral wall and hypokinetic mid lateral wall with reduced systolic functions. An elective coronary angiography (CAG) revealed a 90% stenosis of mid left anterior descending (LAD) artery and an 80% stenosis on the proximal left circumflex artery. He underwent a successful PCI with a drug-eluting stent implantation to mid LAD. He was discharged in a stable state 48 h post revascularization with dual antiplatelet (clopidogrel and acetylsalicylic acid). Seven days later, he presented with a crushing substernal chest pain. Cardiac enzymes were elevated and ECG revealed anterior ST-elevation MI. An emergency CAG revealed a high thrombus burden with 100% occlusion of mid LAD. Following unsuccessful ballooning, intravenous and intracoronary thrombolysis with tenecteplase was given. A TIMI II flow was achieved and the patient was sent to the coronary care unit. However, 14 h later there was yet a new onset of severe chest pain. A 12-lead ECG previewed anterior ST-elevation MI and the cardiac enzymes were high. Urgent CAG revealed in-stent thrombotic total occlusion of mid LAD. A stent in stent was then implanted and TIMI III flow was restored. Clopidogrel resistance was suspected and the patient was transitioned to ticagrelol. There were no further ischemic events during the remainder of hospitalization and the patient was discharged in a hemodynamically stable state three days later. During follow-up after one and three months, he was fairly stable without any further cardiac events. Conclusions: Owing to clopidogrel resistance, stent thrombosis in the setting of dual antiplatelet therapy compliance may occur. While in a situation of clopidogrel resistance newer and more potent antiplatelet drugs should be used, their availability and cost remains a significant barrier particularly in the developing world. Nonetheless, a high index of suspicion and timely revascularization is fundamental to restore patency of the thrombosed vessel and confer better risk-adjusted survival rates. [ABSTRACT FROM AUTHOR]

Introduction: Clopidogrel is recommended as an alternative to Acetyl Salicylic Acid (ASA), the first-line drug for secondary stroke prevention. Clopidogrel resistance in Indonesia is reportedly 15.8%. The Stent Thrombosis in Belgium (STIB) is a scoring system proposed to assess clopidogrel resistance which has not been tested for the reliability in Indonesian population. Objectives: The objective of the study is to test the reliability of the STIB scoring and modified-STIB scoring system in Indonesian population. Methods: This study was conducted cross-sectionally in Dr. Cipto Mangunkusumo Hospital and Universitas Indonesia Hospital from January 2020 to December 2021. Laboratory examinations of human CYP450 concentration in blood plasma from 112 subjects were carried out using the ELISA method. The clopidogrel resistance test was carried out using the VerifyNow method. Results: Out of 112 ischemic stroke patients in this study, 14.3% of them did not respond to clopidogrel. Cross-tabulation between the STIB score and clopidogrel resistance showed significant results (p < 0.05) on the Hb variable and a combination of two or three factors involving Hb levels. Both Hb and CYP450 levels can be independent factors predicting clopidogrel resistance. Once combined, the Hb and CYP450 cutoff levels of 458.9 pg/mL had a sensitivity of 100% with a specificity of 30.2%. Conclusions: STIB scoring system did not prove to be reliable in screening for Clopidogrel resistance in Indonesian population. The modified STIB scoring system proposed in this study showed a promising result. Further research with larger population should be conducted. [ABSTRACT FROM AUTHOR]

Rakhmad Hidayat,1– 3 Al Rasyid,2,3 Salim Harris,2,3 Alida Harahap,2 Herqutanto,2 Melva Louisa,2 Erlin Listiyaningsih,4 Aldy Safruddin Rambe,5 Tonny Loho6 1Doctoral Program in Medical Sciences Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia; 2Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia; 3Dr. Cipto Mangunkusumo Hospital, Jakarta, Indonesia; 4Harapan Kita Hospital, Jakarta, Indonesia; 5Sumatera Utara University, Medan, Indonesia; 6Faculty of Medicine and Health Science, Kristen Krida Wacana University, Jakarta, IndonesiaCorrespondence: Rakhmad Hidayat, Tel +62 813 88756299, Email rhidayat.md@gmail.comBackground: Stroke is one of the highest causes of disability and mortality in several countries worldwide. Secondary prevention is important in the management of stroke. Clopidogrel is widely used in Asia as secondary prevention for ischemic stroke, even though several studies in Western show limited data related to clopidogrel resistance in Asia. This study aims to determine the correlation between P2Y12 genetic polymorphism and clopidogrel resistance in Indonesia.Methods: This study was conducted on one-year duration, the subjects were chosen through the consecutive sampling method, all subjects were examined for genetics and resistance to clopidogrel. The data were analyzed through statistical analysis, a bivariate analysis was conducted to determine the correlation between several variables and the resistance variable. This study employed resistance diagnostic methods with VerifyNow. Polymorphism of receptor P2Y12 was tested with the Polymerase Chain Reaction method (PCR) and analysis of restriction fragment length polymorphism (RFLP). The genes tested in this study were G52T and C34T.Results: The number of participants in this study was 112. Examination of gene P2Y12 showed that the majority was homozygote, wild-type C34T allele (67%), and G52T (66.1%). There was no significant correlation between clopidogrel resistance and gene G52T and C34T of P2Y12 (p > 0.05). Hb levels significantly correlated with P2Y12 G52T (p = 0.024). Meanwhile, Fatty Liver significantly correlated with P2Y12 C34T (p = 0.037).Conclusion: Indonesia showed a low clopidogrel resistance rate and a very low C34T and G52T allele P2Y12 gene mutation, meaning that Indonesia had low mutations in the P2Y12. This is the cause of clopidogrel resistance in this study only 15%. Therefore, in a region with less clopidogrel resistance, examination of the P2Y12 gene would not give significant results.Keywords: clopidogrel resistance, P2Y12, stroke, antiplatelet

Background: Credible diagnostic stratification remains a challenge for coronary artery disease patients with clopidogrel resistance after percutaneous coronary intervention. Tongue diagnostic parameters-based diagnostic signatures might predict clopidogrel resistance.Methods: Clinical and tongue diagnostic parameters data were obtained from coronary artery disease patients with clopidogrel resistance after percutaneous coronary intervention patients and then analyzed. Tongue diagnostic parameters-based diagnostic signatures were developed through univariate and multivariate logistic regression analysis. The diagnostic prediction was assessed using a receiver operating characteristic curve.Results: A total of 101 patients were consecutively identified. Then, tongue diagnostic parameters were identified as significantly associated with clopidogrel resistance diagnosis and were combined with risk factors to develop a model. The receiver operating characteristic curve analysis showed that tongue diagnostic parameters-based diagnostic signatures performed well in diagnosing clopidogrel resistance with an area under the receiver operating characteristic curve value of 0.819.Conclusions: This study identified a novel tongue diagnostic parameters-based diagnostic signature to reliably distinguish clopidogrel resistance diagnosis in coronary artery disease patients undergoing percutaneous coronary intervention. Further larger, multicenter prospective studies are desired to validate this model. [ABSTRACT FROM AUTHOR]

An 84-year-old patient developed immediate thrombosis of his carotid stent in recovery after transcarotid artery revascularization. In the present report, the technical details about intraoperative management for neurovascular rescue using the transcarotid artery revascularization flow-reversal system are described. The patient was determined to have clopidogrel resistance. Intraoperative medical management is also discussed. The current alternative intravenous and oral antiplatelet therapies such as glycoprotein IIb/IIIa and P2Y12 inhibitors are explored. The debate regarding preoperative antiplatelet resistance testing remains ambiguous, and increasing studies have demonstrated the safety and efficacy of alternatives to clopidogrel. Despite an unpredictable and devastating complication, the patient’s outcome was successful using contemporary strategies.

Objective To study the relationship between clopidogrel resistance and CYP2C19 gene polymorphism and P2Y12 receptor in stroke patients. Methods A total of 298 patients with ischemic stroke who were hospitalized in Guizhou Aerospace Hospital from January 2019 to December 2020 were selected, and their CYP2C19 and P2Y12 genotypes were detected before taking clopidogrel, and CYP2C19*2 (GA type + AA type) patients, observe the difference of platelet aggregation rate of different P2Y12 gene loci C34T, G52T, i-T774C before medication and 7 days after medication, and analyze the correlation. Results The patients with CYP2C19* 1/*1 genotype had the highest proportion (39.9%), and the patients with CYP2C19* 3/* 3 and CYP2C19*1/*17 genotype had the lowest proportion (both 0.3%). Among them, 4 cases of UM type ( 1.3%), EM type 119 cases (39.9%), IM type 133 cases (44.7%), PM type 42 cases (14.1%). Among the CYP2C19*2 patients, 83 cases (56.5%) of CC type in the P2Y12 gene polymorphism C34T site group, 56 cases (38.1%) of CT type, 8 cases (5.4%) of TT type, and 91 cases (5.4%) of GG type in the G52T site group ( 62.8%), GT type in 48 cases (33.1%), and TT type in 6 cases (4.1%); there was no statistically significant difference in platelet aggregation rate difference between genes before and after taking clopidogrel (P>0.05). Among CYP2C19*2 patients, in the P2Y12 gene polymorphism i T744C site group, 78 cases (52.7%) were TT type, 60 cases (40.5%) were TC type, and 10 cases (6.8%) were CC type. The difference of platelet aggregation rate was statistically significant (P<0.05). Conclusion The distribution of genes in stroke patients is dominated by EM and IM types. The C34T and G52T sites in the P2Y12 receptor may not be significantly related to the antiplatelet effect of clopidogrel. The i-T744C site is related to platelet activity. It is one of the causes of clopidogrel resistance in stroke patients. [ABSTRACT FROM AUTHOR]

Clopidogrel resistance (CR) increases the risk of atherothrombotic events. Emerging evidence suggests that circRNAs may influence pharmacodynamic responses to clopidogrel. A total of 25 CR and 25 non-clopidogrel resistance (NCR) patients were enrolled. To identify circRNAs and miRNAs associated with CR, a microarray analysis was performed on RNA samples from 5 CR to 5 NCR patients. Based on the 10 most dysregulated circRNAs, a circRNA-miRNA network was constructed to explore target interactions. Next, the expression of selected circRNAs and their targeted mRNAs was measured, and their diagnostic value for CR was evaluated. Through joint analysis, the candidate miRNAs were identified and verified by RT‒PCR. Finally, after THLE-2 cells were cultivated and transfected with plasmids, the interactions among circ_007695, miR-4512 and COL19A1 were detected. Our present study revealed circRNA and miRNA microarray expression profiles in CR and NCR patients and constructed a circRNA‒miRNA network. Moreover, in the CR group, hsa_circ_0076837, hsa_circ_0057714, and hsa_circ_0076957 were downregulated, and the mRNA expression of AOX1 and COL19A1 was also lower in these CR patients. ROC curve analysis indicated that hsa_circ_0057714 (targeting AOX1) and hsa_circ_0076957 (targeting COL19A1) may serve as reliable biomarkers for distinguishing CR. Furthermore, we revealed that the level of miR-4512 was greater in CR and circ-0076957 could regulate COL19A1 expression by targeting miR4512 in THLE-2 cells. These findings highlight hsa_circ_0057714 and hsa_circ_0076957 as novel biomarkers for CR and suggest that circ-0076957 may regulate COL19A1 expression by targeting miR-4512, providing insights that could improve management of clopidogrel resistance in CAD. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Kawasaki disease (KD) is a pediatric vasculitis. Mainly the coronary arteries become affected due to acute inflammation and formation of coronary artery aneurysms (CAAs) can occur. The larger the CAA, the higher the risk for clinical complications and major adverse cardiac events, as the blood flow changes to vortex or turbulent flow facilitating thrombosis. Such patients may develop life threatening thrombotic coronary artery occlusion and myocardial ischemiaunless anti-platelet and anti-coagulation therapy is timely initiated. Case presentation We present a unique case of a 5-year-old girl with KD associated giant CAAs suffering from myocardial ischemia due to acute progressive thrombus growth despite intensive anticoagulation treatment (acetylsalicylic acid, acenocoumarol and clopidogrel) after 21 months of onset of disease. Thrombus growth continued even after percutaneous coronary intervention (PCI) with thrombolytic treatment and subsequent systemic thrombolysis, finally causing lasting myocardial damage. Acute coronary artery bypass grafting (CABG) was performed, although technically challenging at this very young age. Whereas myocardial infarction was not prevented, follow-up fortunately showed favorable recovery of heart failure. Conclusions Anticoagulation and thrombolysis may be insufficient for treatment of acute coronary syndrome in case of impending thrombotic occlusion of giant coronary aneurysms in KD. Our case demonstrates that a thrombus can still continue to grow despite triple anticoagulation therapy and well-tailored cardiovascular follow-up, which can be most likely attributed to the state of low blood flow inside the aneurysm.

Despite patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) and receiving clopidogrel therapy, some patients still experience major adverse cardiovascular events (MACEs). Clopidogrel resistance, which may be regulated by genetic and epigenetic factors, may play a role in MACEs. This study aimed to determine the association between genetic (CYP2C19 and P2Y12 polymorphisms) and epigenetic (DNA methylation of CYP2C19 and P2Y12 and miRNA-26a expression) factors and their effects on MACEs among post-PCI patients. Post-PCI patients who received a standard dosage of clopidogrel at Harapan Kita Hospital between September 2018 and June 2020 were included in this study. MACEs were observed in patients within 1 year after PCI. Platelet aggregation was assessed using light transmission aggregometry (LTA). DNA methylation of CYP2C19 and P2Y12 was assessed using the bisulfite conversion method. CYP2C19 and P2Y12 polymorphisms and miRNA-26a expression were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). Among a total of 201 subjects, 49.8% were clopidogrel-resistant, and 14.9% experienced MACEs within 1 year after PCI (death was 7.5%). Hypomethylation of CYP2C19 (p = 0.037) and miRNA-26a upregulation (p = 0.020) were associated with clopidogrel resistance. CYP2C19*2/*3 polymorphisms (p = 0.047) were associated with MACEs in 1 year. This study demonstrated that hypomethylation of CYP2C19 and miRNA-26a upregulation increased the risk of clopidogrel resistance in post-PCI patients, but there was no correlation between clopidogrel resistance and MACEs. However, CYP2C19*2/*3 polymorphisms were the factors that predicted MACEs within 1 year.

Purpose: We aimed to assess whether the aberrant methylation of GNAQ gene, which may involve in the clopidogrel resistance (CR), was associated with a higher risk of recurrent ischemic events in clopidogrel-treated acute ischemic stroke or transient ischemic attack (TIA) patients. Methods: This is a nested case-control study, 152 clopidogrel-treated acute ischemic stroke or TIA patients that were propensity-matched were included in the final analysis, including 36 patients with vascular recurrence set as cases. Methylation levels of GNAQ gene were identified with MassARRAY EpiTYPER assays. Univariate and multivariate logistic regression analyses were conducted to explore the predictive value of CpG units for recurrent ischemic events within 1 year.Mediation analysis was performed to assess the role of CR in describing the effect of GNAQ methylation on recurrent ischemic events. Results: A total of 16 differentially methylated CpG units were identified. Multivariate logistic analysis indicated that the average methylation of CpG 32–39 of GNAQ was associated with a significantly higher risk of ischemic events (p < 0.001). When transformed into dichotomous variables with the receiver operating characteristic curve, hypomethylation (<0.31) of CpG 32–39 of GNAQ significantly increased the risk of vascular recurrence (odds ratio 73.82, 95% confidence interval 20.33–268.01). The mediation effect of CR for recurrent ischemic events was not identified. Conclusions: Hypomethylation of CpG 32–39 of GANQ gene was associated with a higher risk of ischemic events for clopidogrel-treated acute ischemic stroke or TIA patients. Further studies were warranted to explain the possible mechanism. [ABSTRACT FROM AUTHOR]

Objective : To evaluate the stent apposition of a low-profile visualized intraluminal support (LVIS) device in distal internal carotid artery (ICA) aneurysms, examine its correlation with clinical and angiographic outcomes, and determine the predictive factors of ischemic adverse events (IAEs) related to stent-assisted coiling. Methods : We retrospectively analyzed a prospectively maintained database of 183 patients between January 2017 and February 2020. The carotid siphon from the cavernous ICA to the ICA terminus was divided into posterior, anterior, and superior bends. The anterior bends were categorized into angled (V) and non-angled (C, U, and S) types depending on the morphology and measured angles. Complete stent apposition (CSA) and incomplete stent apposition (ISA) were evaluated using unsubtracted angiography and flat-panel detector computed tomography. Dual antiplatelet therapy with aspirin 200 mg and clopidogrel 75 mg was administered. Clopidogrel resistance was defined as fewer responders (≥10%, <40%) and non-responders (<10%) based on the percent inhibition (%INH) of the VerifyNow system. These were counteracted by a dose escalation to 150 mg for fewer responders or substitution with cilostazol 200 mg for non-responders. IAEs included intraoperative in-stent thrombosis, transient ischemic attack, cerebral infarction, and delayed in-stent stenosis. A multivariate logistic regression analysis was used to determine the predictive factors for ISA and IAEs. Results : There were 33 ISAs (18.0%) and 27 IAEs (14.8%). The anterior bend angle was narrower in ISA (-4.16°±25.18°) than in CSA (23.52°±23.13°) (p<0.001). The V- and S-types were independently correlated with the ISA (p<0.001). However, treatment outcomes, including IAEs (15.3% vs. 12.1%), aneurysmal complete occlusion (91.3% vs. 88.6%), and recanalization (none of them), did not differ between CSA and ISA (p>0.05). The %INH of 27 IAEs (13.78%±14.78%) was significantly lower than that of 156 non-IAEs (26.82%±20.23%) (p<0.001). Non-responders to clopidogrel were the only significant predictive factor for IAEs (p=0.001). Conclusion : The angled and tortuous anatomical peculiarity of the carotid siphon caused ISA of the LVIS device; however, it did not affect clinical and angiographic outcomes, while the non-responders to clopidogrel affected the IAEs related to stent-assisted coiling. [ABSTRACT FROM AUTHOR]

BackgroundCYP2C19 genetic variation and clinical factors have been proved to be related with clopidogrel resistance (CR) in adults, while the presence of CR in children with Kawasaki disease (KD) was seldom reported. Our objective was to evaluate KD patients’ response to clopidogrel treatment and determine whether CYP2C19 gene polymorphisms and laboratory indicators are associated with CR in this population.MethodsThis was a prospective and single-center study. We recruited children with KD hospitalized in the cardiology department at the Children’s Hospital Capital Institute of Pediatrics between January 2019 and October 2021, and the distribution of the CYP2C19 gene polymorphisms was assessed. According to the light transmission aggregometry (LTA) test results, KD patients who were treated with clopidogrel were divided into CR group and non-CR (NCR) group. We also analyzed the influence of CYP2C19 gene polymorphisms and laboratory indicators on CR in children with KD.Results(1) A total of 346 children with KD were evaluated for the genotypic and phenotypic distributions of CYP2C19. Loss-of-function (LOF) mutated allele was included in 56.9% of CYP2C19 genotypes, and their corresponding phenotypes were intermediate metabolizers (46.2%) and poor metabolizers (10.7%). (2) The incidence of CR in this study population was 31.4%. The multivariate logistic regression showed that carrying CYP2C19 LOF allele (OR, 3.922; 95%CI, 1.504–10.282; P = 0.005) and high levels of low-density lipoprotein (OR, 1.675; 95%CI, 1.069–2.623; P = 0.024) were independent risk factor for CR, while low levels of high-density lipoprotein (OR, 0.120; 95%CI, 0.020, 0.734; P = 0.022) was an independent protective factor for CR. The area under the receiver operator characteristic curve of the multivariate logistic regression model (including high-density lipoprotein, low-density lipoprotein, and CYP2C19 LOF allele carriers) for predicting CR was 0.769 (95% CI, 0.674–0.863; P < 0.001). The sensitivity and specificity were 70.3 and 74.0%, respectively.ConclusionCarrying CYP2C19 LOF allele, low levels of high-density lipoprotein, and high levels of low-density lipoprotein were independent risk factors for CR in children with KD in China. This may benefit pediatricians in choosing appropriate individualized antiplatelet therapy.

Clopidogrel, an antiplatelet agent used for secondary prevention of cerebrovascular diseases, is often taken with proton pump inhibitors (PPIs). Generally, the combined use of clopidogrel and PPIs causes adverse drug–drug interactions. VerifyNow is a quick and convenient method to confirm clopidogrel resistance (CR), which compromises adequate antithrombotic effects. We aimed to confirm CR, identify its factors, and determine the influence of the combination of ilaprazole and clopidogrel on clopidogrel using VerifyNow. In this retrospective study, we examined patients who were receiving clopidogrel after three months, starting within one week from the onset of cerebral infarction symptoms. Clinical records, imaging records, and diagnostic laboratory results, including P2Y12 reaction units (PRU), were compared and analyzed to check for CR. Additionally, the groups treated with either both ilaprazole and clopidogrel or with medications other than ilaprazole were comparatively analyzed. CR was defined as a PRU ≥240 after clopidogrel for three months. Among factors influencing CR by affecting clopidogrel metabolism, positive statistical correlations with age and alcohol consumption were confirmed. The diagnostic tests revealed a lower glomerular filtration rate and platelet count of the CR-positive group. This finding proved that the combination therapy of ilaprazole and clopidogrel is safe, as it does not interfere with the metabolism of clopidogrel. [ABSTRACT FROM AUTHOR]

The purpose was to explore the value of high on-treatment platelet reactivity (HTPR) in predicting long-term clinical outcomes for stroke patients. The platelet reactivity was assayed after being treated with either 75 mg clopidogrel or 100 mg aspirin daily with VerifyNow System in stroke patients. HTPR for clopidogrel was defined as PRU ≥ 208, and that for aspirin was defined as ARU ≥ 550. CYP2C19 genotyping was performed using the Sequenom MassARRAY iPLEX platform. The primary endpoint was a composite of recurrent ischemic stroke, transient ischemic attack, myocardial infarction, or ischemic vascular death. The safety endpoint was bleeding. In the clopidogrel group, among 345 patients recruited, 174 of them were categorized as HTPR. A total of 270 patients were followed up for 54 months. There was a significant association between HTPR and the primary endpoint (HRadj 2.13 [95% CI, 1.43–3.15], p < 0.001). Among the 314 participants genotyped for CYP2C19, 187 (59.6%) were classified as CYP2C19 loss-of-function allele carriers. Patients with at least 1 loss-of-function allele were more likely to present with HTPR (ORadj 2.61 [95%CI, 1.43–4.77], p = 0.008), and had a higher risk of the primary endpoint (HRadj 2.05 [95% CI, 1.30, 3.25], p = 0.002). In the aspirin group, among 140 patients recruited, 28 of them were categorized as HTPR. A total of 121 patients were followed up for 30 months. Similarly, there was a significant association between HTPR and the primary endpoint (HRadj 3.28 [95% CI, 1.52–7.71], p = 0.002). HTPR is an independent risk factor for ischemic events during long-term follow-up in stroke patients. Platelet function testing is helpful to evaluate the effect of antiplatelet therapy for stroke patients. [ABSTRACT FROM AUTHOR]

Fang Chen,1 Jing Zhang,2 Cheng-Xue Bian,2 Jian Zhang,3 Xiang-Bin Xin,2 Yang-Yang Pan,2 Xuan Zhang2 1Department of Cardiology, Yinchuan First People’s Hospital, Yinchuan, People’s Republic of China; 2Department of Cardiology, Ningxia Medical University, Yinchuan, People’s Republic of China; 3Department of Clinical Laboratory, Yinchuan First People’s Hospital, Yinchuan, People’s Republic of ChinaCorrespondence: Fang ChenDepartment of Cardiology, Yinchuan First People’s Hospital, No. 2 of Liqun West Street, Xingqing District, Yinchuan, 750000, People’s Republic of ChinaTel +86 0951-6997179Fax +86 0951-6192355Email cf720302@126.comObjective: This study assesses the correlation between MDR1 gene polymorphism and clopidogrel resistance (CR) in Hui patients with coronary heart disease (CHD) who were treated with percutaneous coronary intervention (PCI).Methods: The study includes 204 Ningxia Hui patients with CHD who were treated with PCI. These patients were divided into two groups: those who with CR and others were non-clopidogrel resistant (NCR), according to the results of the patients’ platelet aggregation rate, which was tested by adenosine diphosphate-induced turbidimetry on the second postoperative day. C3435T and C1236T genotypes and alleles were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).Results: The CR rate was 24.0%, and there were 3 genotypes of C3435T and C1236T. For C3435T, the distribution frequency of the 3435TT genotype and T allele was significantly higher in the CR group than in the NCR group. For C1236T, no significant difference was found between the two groups.Conclusion: Hui patients who had CHD were treated with PCI. CR was most likely to occur in those who had the T allele of MDR1 in gene C3435T.Keywords: coronary heart disease, MDR1 gene, clopidogrel resistance, gene polymorphism, platelet aggregation rate

Objective. Clopidogrel is a common antiplatelet used as secondary prevention of ischemic stroke, known to have better efficacy than aspirin, with a equivalent safety profile. However, clopidogrel resistance is not uncommon but has not been widely studied in Asia. This study will further assess clopidogrel resistance and its risk factors. Materials and Methods. A cross-sectional study was conducted at Rumah Sakit Universitas, Indonesia, and Rumah Sakit Cipto Mangunkusumo, Indonesia in 2020-2021. All patients had had at least one episode of ischemic stroke. Clopidogrel resistance was assessed using a VerifyNow assay. Results. 57 subjects were enrolled in this study. We found 15.8% of subjects were clopidogrel resistant. Gender was significantly associated with clopidogrel resistance, with males having 80% lower clopidogrel resistance (OR 0.2 (95% CI 0.022 - 0.638); P=0.006). Meanwhile, smoking was not associated with clopidogrel responsiveness (P=0.051). We found no association between haemoglobin, blood glucose, HbA1c, cholesterol, liver enzymes, serum urea concentration or creatinine levels and clopidogrel resistance. Conclusion. Clopidogrel remains an effective treatment to prevent recurrent ischemic stroke in Indonesia. Further studies are needed to assess gene polymorphism and clopidogrel resistance, which may explain the findings of this study. [ABSTRACT FROM AUTHOR]

Background: Kawasaki disease (KD) is a pediatric vasculitis. Mainly the coronary arteries become affected due to acute inflammation and formation of coronary artery aneurysms (CAAs) can occur. The larger the CAA, the higher the risk for clinical complications and major adverse cardiac events, as the blood flow changes to vortex or turbulent flow facilitating thrombosis. Such patients may develop life threatening thrombotic coronary artery occlusion and myocardial ischemiaunless anti-platelet and anti-coagulation therapy is timely initiated.Case Presentation: We present a unique case of a 5-year-old girl with KD associated giant CAAs suffering from myocardial ischemia due to acute progressive thrombus growth despite intensive anticoagulation treatment (acetylsalicylic acid, acenocoumarol and clopidogrel) after 21 months of onset of disease. Thrombus growth continued even after percutaneous coronary intervention (PCI) with thrombolytic treatment and subsequent systemic thrombolysis, finally causing lasting myocardial damage. Acute coronary artery bypass grafting (CABG) was performed, although technically challenging at this very young age. Whereas myocardial infarction was not prevented, follow-up fortunately showed favorable recovery of heart failure.Conclusions: Anticoagulation and thrombolysis may be insufficient for treatment of acute coronary syndrome in case of impending thrombotic occlusion of giant coronary aneurysms in KD. Our case demonstrates that a thrombus can still continue to grow despite triple anticoagulation therapy and well-tailored cardiovascular follow-up, which can be most likely attributed to the state of low blood flow inside the aneurysm. [ABSTRACT FROM AUTHOR]

Background: Carriers of cytochrome 2C19 (CYP2C19) loss-of-function (LoF) alleles treated with clopidogrel have impaired drug metabolism, resulting in reduced active metabolite levels, high platelet reactivity (HPR), and an increased risk of thrombotic events. Several alternative antiplatelet therapies have been proposed to overcome HPR in these patients, but their comparative effects remain poorly explored., Methods: Randomized controlled trials (RCTs) comparing different oral antiplatelet therapies in carriers of CYP2C19 LoF alleles undergoing percutaneous coronary interventions (PCI) were included. A frequentist network meta-analysis was conducted to estimate mean difference (MD) or odds ratios and 95% confidence intervals (CI). The primary outcome was platelet reactivity assessed by VerifyNow and reported as P2Y12 reaction unit (PRU). The secondary outcome was the rate of HPR. Standard dose of clopidogrel (75 mg daily) was used as a reference treatment., Results: A total of 12 RCTs testing 6 alternative strategies (i.e. clopidogrel 150 mg, prasugrel 3.75 mg, 5 mg, and 10 mg, ticagrelor 90 mg bid, and adjunctive cilostazol 100 mg bid) were included in the network. Compared with standard-dose clopidogrel, the greatest reduction in PRU was observed with prasugrel 10 mg (MD -127.91; 95% CI -141.04; -114.78) and ticagrelor 90 mg bid (MD -124.91; 95% CI -161.78; -88.04), followed by prasugrel 5 mg (MD -76.33; 95% CI -98.01; -54.65) and prasugrel 3.75 mg (MD -73.00; 95% CI -100.28; -45.72). Among other strategies, adjunctive cilostazol (MD -42.64; 95% CI -64.72; -20.57) and high-dose clopidogrel (MD -32.11; 95% CI -51.33; -12.90) were associated with a modest reduction in PRU compared with standard-dose clopidogrel., Conclusion: Among carriers of CYP2C19 LoF alleles undergoing PCI, standard-dose prasugrel or ticagrelor are most effective in reducing platelet reactivity, while double-dose clopidogrel and additional cilostazol showed modest effects. Reduced-dose of prasugrel may represent a balanced strategy to overcome HPR without a significant increase in bleeding. The clinical implications of these pharmacodynamic findings warrant further investigation., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Clopidogrel resistance (CR) is associated with adverse clinical outcomes in acute ischemic stroke or transient ischemic attack (TIA) patients. However, whether CR affects the long-term clinical prognosis remains to be clarified. The ABCD-GENE score is a novel risk model that identifies CR in cardiovascular disease patients; its diagnostic ability and application in ischemic stroke or TIA remain to be studied. This study aimed to investigate the diagnostic ability of the ABCD-GENE score for CR and analyze the relationship between CR and long-term clinical prognosis in patients with ischemic stroke or TIA., Methods: From January 2018 to January 2021, 251 ischemic stroke or TIA patients who were treated with clopidogrel for more than three months after onset and maintained the medication until the follow-up time were enrolled, and platelet reactivity was detected by thromboelastography. CYP2C19 gene analysis was performed. Adverse clinical outcomes were recorded from 3months after onset. The median follow-up time was 878days., Results: The prevalence of CR was 33.9%. The proportion of CYP2C19 loss-of-function carriers was 62.2%. The ABCD-GENE score≥10 was independently associated with CR (OR=1.82, 95% CI: 1.02-3.24, P=0.041), and the C-statistic value of the score (as a binary and integer variable) on CR was 0.58 and 0.63, respectively. The risk of long-term adverse clinical outcomes was not significantly different between CR and clopidogrel sensitive groups (12.94% vs. 11.44%, HR=1.22, 95% CI: 0.57-2.62, P=0.603). A similar result was observed between ABCD-GENE score≥10 and ABCD-GENE score<10 groups (10.38% vs. 12.64%, HR=1.19, 95% CI: 0.55-2.60, P=0.666)., Conclusions: In ischemic stroke or TIA patients, the ABCD-GENE score could identify the risk of CR. CR was not associated with long-term adverse clinical outcomes., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Aneurysm treatment using the Pipeline Embolization Device has been established but appropriate maintenance of dual antiplatelet therapy (APT) is essential. This multicenter retrospective study assessed whether APT was properly adjusted for clopidogrel resistance and identified risk factors associated with periprocedural complications. Consecutive cases of use of the Pipeline Embolization Device for internal carotid artery aneurysms (>10 mm) between November 2015 and April 2020 were analyzed. Dual APT (aspirin + clopidogrel) was prescribed before treatment. If preprocedural P2Y12 reaction unit (PRU) values were >240, APT was adjusted. Periprocedural complications were compared between APT nonadjustment and adjustment groups and periprocedural risk factors were also analyzed. A total of 162 procedures were assessed. The mean maximum aneurysm size was 15.35 mm. APT adjustment was required in 47 cases (29.0%), primarily by switching to prasugrel. There were no significant differences in complication incidence between the 2 groups even after propensity score matching. The risk factor independently associated with ischemic complications was a neck size of 8 mm or larger (odds ratio [OR], 5.25; P = 0.018) and restricting analysis to the APT nonadjustment group showed PRU values of 190 or higher (OR, 5.84; P = 0.047) and neck sizes of 8 mm or larger (OR, 7.05; P = 0.029) as significant factors. The risk factor independently associated with hemorrhagic complications was a neck size of 7 mm or larger (OR, 11.57; P = 0.023). APT adjustment for clopidogrel resistance was safe and effective. Neck width was a risk factor for both ischemic and hemorrhagic complications. PRU values of 190 or higher were also associated with ischemic complications. [ABSTRACT FROM AUTHOR]

Since aspirin and clopidogrel are the widely and conventionally used drugs to treat acute myocardial infarction after percutaneous coronary intervention (PCI), it is important to explore potential risk factors of their resistance. The platelet aggregation rate with arachidonic acid (AA, PAg-AA%) and adenosine diphosphate (ADP, PAg-ADP%) of 219 PCI patients were measured after standard treatment for 24 h. The disease history and laboratory data (before PCI) were obtained. We found 101 (46.12%) patients to be aspirin-resistant, and PAg-ADP% was the most prominent risk factor of aspirin resistance. Clopidogrel resistance was present in 157 of 219 patients. Patients in the clopidogrel-resistant group carried more CYP2C19*3 or *2, which was associated with higher clopidogrel resistance in this group (69.11%, 47/68) than in the control group (64.29%, 36/56). Platelet count (109/L) and hemoglobin (g/L) were the prominent risk factors of clopidogrel resistance. Among the 219 patients, 98 showed dual antiplatelet drug resistance, for which platelet count (109/L) and monocyte count (g/L) were the risk factors. Aspirin resistance was found to usually accompany clopidogrel resistance. [ABSTRACT FROM AUTHOR]

To investigate the differences in the correlation between multidrug resistance protein 1 (MDR1) (ABCB1) gene polymorphism and clopidogrel resistance in patients of the Hui and Han nationalities with percutaneous coronary intervention (PCI). A total of 377 subjects (154 people of Hui nationality, 223 people of Han nationality) with PCI were enrolled in the study. Each patient's platelet aggregation rate was induced by adenosine diphosphate and measured using light turbidimetry. Based on the results, the patients were divided into two groups: a clopidogrel resistance (CR) group and a non-clopidogrel resistance (NCR) group. Restrictive fragment-length polymorphism polymerase chain reaction technology was then used to determine the genotype and alleles at two loci (C3435 T[rs1045642] and C1236 T[rs1128503]), calculate the frequencies of the genotype and alleles at these two loci, and conduct correlation analysis. The incidence rate of clopidogrel resistance was 23.4%, and the frequencies of the TT genotype and T allele at C3435 T for patients of both nationalities were significantly higher in the CR group than in the NCR group (P < 0.05). There were no significant differences between the two groups in genotype or allele frequency at C1236 T. There was a significant difference in the distribution of C1236 T polymorphism between the two nationalities (P < 0.05), but there was no significant difference between the two nationalities in C3435 T polymorphism. Patients with a T allele at MDR1 C3435 T are more likely to show clopidogrel resistance, and no significant differences were identified in C3435 T gene polymorphism between the two nationalities. [ABSTRACT FROM AUTHOR]

Objective: To explore the treatment effect of statins used together with clopidogrel on cerebral infarction (CI).Methods: One hundred and thirty non-clopidogrel resistant patients were divided into a dynamic clopidogrel resistant (DCR) group and a continuous Non clopidogrel resistance (NCR) group. Patients were randomly assigned to AC group (atorvastatin 40 mg/d + clopidogrel, 51 patients) and RC group (rosuvastatin 20 mg/d + clopidogrel, 47 patients). The patient’s platelet aggregation rate (PAR) was measured on visit 0 (baseline), visit 1 (1 week after clopidogrel alone treatment), and visits 2 to 4 (one, three, and 6 months after clopidogrel plus statins treatment). The platelet reactivity index (PRI) was assessed on visits 0, 2, and 4, and clopidogrel thiol metabolite (H4) levels was measured on visits 2 and 4. DNA sequencing was used to determine CYP3A4, CYP2C9, and CYP2C19 genotypes in all patients.Results: PAR, PRI, and H4 levels, DCR ratio, and the genotype frequencies of CYP2C9*3εC, CYP2C19*2εA, and CYP2C19*3εA of both groups were similar (p > 0.05). CYP2C19εA *2 and *3 were independent risk factors for DCR (p < 0.05).Conclusion: Clopidogrel combined with atorvastatin does not affect platelet inhibition and does not increase the incidence of DCR. The incidence of DCR in the Chinese population is high and is related to CYP2C19εA.