High on-clopidogrel platelet reactivity in ischaemic stroke or transient ischaemic attack: Systematic review and meta-analysis

Revolutionizing Stroke Care: Nanotechnology-Based Brain Delivery as a Novel Paradigm for Treatment and Diagnosis

Stroke, a severe medical condition arising from abnormalities in the coagulation-fibrinolysis cycle and metabolic processes, results in brain cell impairment and injury due to blood flow obstruction within the brain. Prompt and efficient therapeutic approaches are imperative to control and preserve brain functions. Conventional stroke medications, including fibrinolytic agents, play a crucial role in facilitating reperfusion to the ischemic brain. However, their clinical efficacy is hampered by short plasma half-lives, limited brain tissue distribution attributed to the blood-brain barrier (BBB), and lack of targeted drug delivery to the ischemic region. To address these challenges, diverse nanomedicine strategies, such as vesicular systems, polymeric nanoparticles, dendrimers, exosomes, inorganic nanoparticles, and biomimetic nanoparticles, have emerged. These platforms enhance drug pharmacokinetics by facilitating targeted drug accumulation at the ischemic site. By leveraging nanocarriers, engineered drug delivery systems hold the potential to overcome challenges associated with conventional stroke medications. This comprehensive review explores the pathophysiological mechanism underlying stroke and BBB disruption in stroke. Additionally, this review investigates the utilization of nanocarriers for current therapeutic and diagnostic interventions in stroke management. By addressing these aspects, the review aims to provide insight into potential strategies for improving stroke treatment and diagnosis through a nanomedicine approach.

Influence of Genetic and Epigenetic Factors of P2Y12 Receptor on the Safety and Efficacy of Antiplatelet Drugs

PURPOSE

P2Y12 receptor inhibitors are drugs that decrease the risk of stent thrombosis and lower the long-term risk of non-stent-related myocardial infarction and stroke. They inhibit the binding of adenosine diphosphate (ADP) to the P2Y12 receptor and effectively reduce platelet reactivity. However, considerable variability in the pharmacodynamics response contributes to a failure of antiplatelet therapy; this phenomenon is especially notorious for older drugs, such as clopidogrel. Some genetic polymorphisms associated with these drugs' metabolic pathway, especially in the CYP2C19 gene, can significantly decrease antiplatelet efficacy. There are few reports on the variability stemming from the target of this drug class that is the P2Y12 receptor itself.

RESULTS AND CONCLUSION

This review summarizes the results of research that focus on the influence of P2Y12 genetic polymorphisms on the pharmacodynamics and the efficacy of P2Y12 inhibitors. We found that the conclusions of the studies are unequivocal, and despite several strong candidates, such as G52T (rs6809699) or T744C (rs2046934), they may not be independent predictors of the inadequate response to the drug. Most probably, P2Y12 genetic polymorphisms contribute to the effect exerted by other gene variants (such as CYP2C19*2/*3/*17), drug interactions, or patient habits, such as smoking. Also, epigenetic modifications, such as methylation or miRNA levels, may play a role in the efficacy of antiplatelet treatment.

Ticagrelor Versus Clopidogrel in Endovascular Therapy for Cerebral Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Antiplatelet therapy is pivotal in endovascular treatment for intracranial aneurysms. However, there is a lack of studies comparing ticagrelor to clopidogrel in patients with aneurysms undergoing endovascular therapy. Additionally, the existing literature lacks adequate sample size, significant subgrouping, and follow-up, making our study important to cover these gaps.

METHODS

We searched 5 databases to collect all relevant studies. Categorical outcomes were pooled as relative risk (R.R.) with a 95% confidence interval (CI). In the single-arm meta-analysis, outcomes were pooled as proportions and their corresponding 95% CI.

RESULTS

This comprehensive analysis of 18 studies involving 2,427 patients. For thromboembolic events, the pooled (R.R.) did not show significant differences, whether considering overall events. A similar pattern was observed for thromboembolic events stratified by aneurysmal rupture status, with no significant differences in overall events. Hemorrhagic events did not also exhibit significant differences in previously mentioned stratifications. Furthermore, there were no substantial differences in death and mRS (0-2) on discharge between Ticagrelor and Clopidogrel. Single-arm meta-analyses for Ticagrelor demonstrated low rates of thromboembolic events, hemorrhage, death, and favorable mRS scores, with associated confidence intervals (CIs). Main line of endovascular treatment did not significantly affect either thromboembolic or hemorrhagic outcomes with Ticagrelor and Clopidogrel.

CONCLUSIONS

We found no significant differences in key outcomes like thromboembolic events, hemorrhagic events, mortality rates, and favorable mRS (0-2) upon discharge in the studied patients between Ticagrelor and Clopidogrel. Moreover, the single-arm meta-analysis for Ticagrelor revealed low rates of thromboembolic events, hemorrhage, mortality, and high rates of favorable mRS scores.

Pharmacogenomic biomarkers in coronary artery disease: a narrative review

Coronary artery disease (CAD) has a high mortality rate. Despite various therapeutic targets, non-responsiveness to drugs remains a prevalent issue. Pharmacogenomics assesses the way an individual's genetic attributes affect their likely response to drug therapy. Single-nucleotide polymorphisms play a crucial role in determining these outcomes. This review offers an overview of single-nucleotide polymorphisms investigated in clinical studies and their associations with drug response/nonresponse in the treatment of CAD. A total of 104 studies of whole sets of chromosomes and several genes were explored. A total of 161 polymorphisms exhibited associations with drug response/nonresponse in CAD across diverse ethnic populations. This pool can serve as a pharmacogenomic biomarker for predicting response to drug therapy in patients with CAD.

Feasibility and comparability of different platelet function tests in acute stroke with or without prior antiplatelet therapy

Background

The clinical course of ischemic and hemorrhagic strokes can be influenced by the coagulation status of individual patients. The prior use of antiplatelet therapy (APT) such as acetylsalicylic acid (ASA) or P2Y12-antagonists has been inconsistently described as possibly increasing the risk of hemorrhagic transformation or expansion. Since clinical studies describing prior use of antiplatelet medication are overwhelmingly lacking specific functional tests, we aimed to implement testing in routine stroke care.

Methods

We used fluorescence-activated cell sorting (FACS) with antibodies against CD61 for thrombocyte identification and CD62p or platelet activation complex-1 (PAC-1) to determine platelet activation. Aggregometry and automated platelet functioning analyzer (PFA-200) were employed to test thrombocyte reactivity. FACS and aggregometry samples were stimulated in vitro with arachidonic acid (AA) and adenosine diphosphate (ADP) to measure increase in CD62p-/PAC-1-expression or aggregation, respectively.

Results

Between February and July 2023, 20 blood samples (n = 11 ischemic strokes; n = 7 hemorrhagic strokes; n = 2 controls) were acquired and analyzed within 24 h of symptom onset. N = 11 patients had taken ASA, n = 8 patients no APT and n = 1 ASA+clopidogrel. ASA intake compared to no APT was associated with lower CD62p expression after stimulation with AA on FACS analysis (median 15.8% [interquartile range {IQR} 12.6-37.2%] vs. 40.1% [IQR 20.3-56.3%]; p = 0.020), lower platelet aggregation (9.0% [IQR 7.0-12.0%] vs. 88.5% [IQR 11.8-92.0%]; p = 0.015) and longer time to plug formation with PFA-200 (248.0 s [IQR 157.0-297] vs. 121.5 s [IQR 99.8-174.3]; p = 0.027). Significant correlations were noted between AA-induced CD62p expression and aggregometry analysis (n = 18; ρ = 0.714; p < 0.001) as well as a negative correlation between CD62p increase and PFA clot formation time (n = 18; ρ = -0.613; p = 0.007). Sensitivity for ASA intake was highest for PFA (81.8% for values ≥155.5 s). The combination of ASA + clopidogrel also affected ADP-induced CD62p and PAC-1 expression.

Conclusion

In the clinical setting it is feasible to use differentiated platelet analytics to determine alterations caused by antiplatelet therapy. Among the tests under investigation, PFA-200 showed the highest sensitivity for the intake of ASA in stroke patients. FACS analysis on the other hand might be able to provide a more nuanced approach to altered platelet reactivity.

Safety of dual antiplatelet therapy using aspirin and low-dose Prasugrel with platelet reactivity testing in flow diverter treatment of intracranial aneurysms

BACKGROUND

Dual antiplatelet therapy (DAPT) is standard care for intracranial stenting to prevent thrombotic complications. Clopidogrel resistance has resulted in patients receiving newer P2Y12 inhibitors like Prasugrel, which may reduce thrombotic complications but could increase haemorrhagic complications. This study, utilising platelet reactivity testing, compared thrombotic and haemorrhagic complications associated with Clopidogrel or 20 mg Prasugrel loading in patients treated with flow diverters (FD) for intracranial aneurysms.

METHODS

We retrospectively analysed prospectively collected data from 225 consecutive FD procedures. All patients received aspirin. 147 cases received Clopidogrel and 82 received Prasugrel. All patients had VerifyNow testing before the procedure.

RESULTS

P2Y12 non-responders were significantly more likely to have thrombotic complications than responders and hyper-responders (7% vs. 2%, p = 0.01). Low-dose Prasugrel resulted in a significantly lower rate of non-responders when compared with Clopidogrel (7% vs. 25%, p < 0.01). We found no statistically significant difference in rates of haemorrhage between the Clopidogrel and Prasugrel groups (2.4% vs. 3.9%, p = 0.47). There were 12 complications (≤7 days) in the Clopidogrel group versus 6 in the Prasugrel group (9% vs. 7.8%, respectively, p = 0.91) and a non-significant reduction in thrombotic complications in the Prasugrel group (5.2% vs. 3.9%, p = 0.88). No significant difference was shown in long-term complications between the groups (p = 0.33).

CONCLUSION

These results support the use of platelet reactivity testing and the safety of low-dose Prasugrel for FD treatment of intracranial aneurysms.

Aspirin and clopidogrel resistance; a neglected gap in stroke and cardiovascular practice in Iran: a systematic review and meta-analysis

OBJECTIVE

Antiplatelet drugs, such as Aspirin and Clopidogrel (Plavix) are effective in the primary prevention of thromboembolic events. They are commonly used to reduce the risk of recurrence of thromboembolism. The body's hemostatic system responds differently to these drugs in different people. Resistance testing for aspirin and Clopidogrel is now recommended before starting antiplatelet therapy.

METHODS

A systematic literature search was performed on May 12, 2021, using the medical search engines PubMed, Scopus, and Web of Science, and the local databases SID and Magiran. After data extraction, a meta-analysis was performed using Comprehensive Meta-Analysis (CMA2) software. The I2 statistic was used to measure heterogeneity between estimates.

RESULTS

Among the 949 papers, Clopidogrel resistance was assessed in 136 patients and Aspirin resistance in 400 patients. The prevalence of Aspirin resistance was found to be 52.1% and the prevalence of Clopidogrel resistance was found to be 20.5%.

CONCLUSION

It seems that in Iran, the issue of Aspirin and Clopidogrel resistance is suboptimally addressed. This pattern could also occur in other developing countries in the Middle East region.

Genotype-guided dual antiplatelet therapy in cerebrovascular disease: assessing the risk and benefits for ethnic populations

INTRODUCTION

Cerebrovascular disease is a leading cause of morbidity and mortality in the world and antiplatelet therapy is a main pharmacologic means of secondary prevention. Clinical information has accumulated about benefit of dual antiplatelet therapy in certain clinical scenarios, genetic causes of antiplatelet resistance and its effect on clinical outcomes, and ethnic and geographic distributions of genetic polymorphisms.

AREAS COVERED

This review covers literature related to the pharmacogenomics of antiplatelet agents with a focus on ethnic variability, antiplatelet resistance, and dual antiplatelet therapy in cerebrovascular disease.

EXPERT OPINION

Selecting patients for dual antiplatelet therapy and specific agents require consideration of multiple factors. Ethnic factors should be considered in certain circumstances, but additional research is needed to determine the generalizability of the findings.

Comparison of Clopidogrel, Prasugrel and Ticagrelor Response of Patients by PFA-100-Innovance Test Results

Devices such as stents and flow diverters require the use of safe and fast antiplatelet therapy. We aimed to compare the responses to clopidogrel, prasugrel, and ticagrelor by assessing the Platelet Function Analysis (PFA-100)-Innovance test results of patients undergoing endovascular stenting to determine their resistance rates. Sixty-one women and 55 men, aged 18-87 years, were included in this study. Patients were divided into three groups: clopidogrel treatment, prasugrel treatment, and ticagrelor treatment. The systemic diseases of the patients, especially hypertension and diabetes, were recorded. The test results were evaluated according to the results for the collagen/epinephrine (COL-EPI), collagen/adenosine (COL-ADP), and P2Y results. The PFA-100-Innovance results for COL-EPI and P2Y were significantly higher for patients treated with prasugrel and ticagrelor compared with patients treated with clopidogrel (COL-EPI, p = 0.001; P2Y, p = 0.001). Clopidogrel resistance was identified in 31 patients (26.7%), and prasugrel resistance was identified in 4 patients (3.4%). Ticagrelor resistance was not detected. Therefore, 30.1% of patients were classified as drug-resistant. Perioperative bleeding was not detected in any patient. Hypertension was the most common disease recorded for patients being treated for cerebral aneurysm, and diabetes was the most common disease recorded for patients who underwent peripheral artery stenting (p = 0.002). Potent antiplatelet agents, such as prasugrel and ticagrelor, have a low rate of resistance but are associated with an increased bleeding risk. Thus, the choice of a suitable drug during the treatment window remains a critical factor when determining treatment strategies.

Low incidence of hemorrhagic complications both during and after surgical procedures in patients maintained on prasugrel single antiplatelet therapy

BACKGROUND AND PURPOSE

Prasugrel (Pra) is a third-generation thienopyridine that inhibits platelet aggregation via irreversible blockade of P2Y12 receptors. While several published studies have examined the use of Pra and acetylsalicylic acid (ASA) in coronary and neurovascular stenting procedures, there is only anecdotal evidence regarding the use of Pra as single antiplatelet therapy (SAPT) in open surgical procedures. This topic has become important because previous studies have revealed that neurovascular devices with antithrombotic coatings can be implanted using non-invasive procedures in patients maintained on Pra SAPT.

MATERIAL AND METHODS

Patients who underwent open surgery under Pra SAPT between March 2020 and February 2022 were evaluated retrospectively. Adequate platelet inhibition both before and after the procedures was verified in all patients using Multiplate (Roche Diagnostics) and VerifyNow (Accriva) tests. Intraoperative and postoperative hemorrhagic events were recorded based on reviews of the procedure reports and interviews with the surgeons.

RESULTS

The study enrolled 21 patients who underwent 23 open surgical procedures while maintained on Pra SAPT. The procedures included one extirpation of a brain arteriovenous malformation, seven extra-intracranial bypass surgeries, four ventriculoperitoneal shunts, one eye enucleation for an intractable orbital infection, two gastrostomies, one bone flap reinsertion after craniectomy, one decompressive craniectomy, one case requiring cranial surgical wound care, one colporrhaphy, one transurethral resection of urinary bladder cancer, two tumor oophorectomy/hysterectomy procedures, and one aneurysm clipping. None of the 23 procedures resulted in excessive intraoperative or postoperative hemorrhage.

CONCLUSION

In a small retrospective series of patients who required antiplatelet therapy for neurovascular indications, Pra SAPT resulted in no significant increase in the incidence of perioperative and postoperative hemorrhagic complications.

Verifynow P2Y12 PRU-Guided Modification of Clopidogrel for Prevention of Recurrent Ischemic Stroke: A Real-World Prospective Cohort Study

INTRODUCTION

Clopidogrel resistance causes recurrent stroke. However, outcomes of modified antiplatelet medications to prevent recurrent ischemic stroke are not well known.

METHODS

Patients who received clopidogrel with and without modification as initial treatment for stroke were recruited and compared. The primary outcome was ischemic stroke and myocardial infarction at the 1-year follow-up. The secondary outcome was bleeding complications.

RESULTS

Overall, 206 patients treated with clopidogrel were enrolled and were divided into the modification (n = 39) and no modification (n = 167) groups. There was a significant difference in the incidence of severe cerebral arterial stenosis between the two groups (modification group, 16/39, 41.03%; no modification group, 36/167, 21.56%, P = 0.012) at baseline. The loss to follow-up rate was 12.14% (25/206). After adjustment for severe cerebral artery stenosis, antiplatelet modification based on the platelet reactivity unit (PRU) value significantly improved in the per protocol set (odds ratio 0.142, 95% confidential interval 0.022-0.898, P = 0.038). The area under the curve of the different PRU cutoff values were 0.630, 0.605, and 0.591 (P = 0.016, 0.051, and 0.092) for PRU 190, 208, and 235, respectively.

CONCLUSION

Verifynow P2Y₁₂ PRU-guided modification of clopidogrel for ischemic stroke significantly improved or prevented recurrence at the 1-year follow-up. Our findings suggest that clopidogrel therapy based on the PRU cutoff value of 190 should be considered to improve outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02618265 (December 1, 2015).

The Effect of Ticagrelor for Endovascular Intervention of Intracranial Aneurysm Patients with or without Clopidogrel Resistant: A Meta-Analysis

Endovascular interventional is an important treatment method for intracranial aneurysms. However, due to the risk of intracranial thrombosis, prophylactic use of antiplatelet drugs is generally required. Clinically, the most commonly used drugs are aspirin and clopidogrel; although the latter can significantly reduce the incidence of thromboembolic complications, there are still some patients with clopidogrel resistance who have ischemic adverse events during antiplatelet therapy. In this study, cohort studies of PubMed, Embase and Cochrane Library Databases were retrieved to compare the efficacy and safety of ticagrelor and clopidogrel in endovascular interventional treatment of intracranial aneurysms. A total of 10 cohort studies involving 1377 patients were included in this study. All patients had intracranial aneurysms and underwent endovascular intervention. Platelet function was measured in four of the studies and switched the patients with clopidogrel resistance to ticagrelor, while the remaining six studies did not test platelet function, but were also treated with ticagrelor or clopidogrel. The results of the study showed that ticagrelor, like clopidogrel, can effectively control thrombotic complications in endovascular interventional patients, and also control the occurrence of ischemic complications in clopidogrel-resistant patients. Ticagrelor, as a novel platelet aggregation inhibitor that can reversibly bind to P2Y12 receptor, can effectively control thromboembolic complications without increasing hemorrhagic complications, and is also effective in patients with clopidogrel resistance.

Clinical non-effectiveness of clopidogrel use for peripheral artery disease in patients with CYP2C19 polymorphisms: a systematic review

PURPOSE

To conduct a systematic review to identify studies that assessed the association between CYP2C19 polymorphisms and clinical outcomes in peripheral artery disease (PAD) patients who took clopidogrel.

METHODS

We systematically searched Ovid EMBASE, PubMed, and Web of Science from November 1997 (inception) to September 2020. We included observational studies evaluating how CYP2C19 polymorphism is associated with clopidogrel's effectiveness and safety among patients with PAD. We extracted relevant information details from eligible studies (e.g., study type, patient population, study outcomes). We used the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I) Tool to assess the risk of bias for included observational studies.

RESULTS

The outcomes of interest were the effectiveness and safety of clopidogrel. The effectiveness outcomes included clinical ineffectiveness (e.g., restenosis). The safety outcomes included bleeding and death related to the use of clopidogrel. We identified four observational studies with a sample size ranging from 50 to 278. Outcomes and comparison groups of the studies varied. Three studies (75%) had an overall low risk of bias. All included studies demonstrated that carrying CYP2C19 loss of function (LOF) alleles was significantly associated with reduced clinical effectiveness and safety of clopidogrel.

CONCLUSIONS

Our systematic review showed an association between CYP2C19 LOF alleles and reduced functions of clopidogrel. The use of CYP2C19 testing in PAD patients prescribed clopidogrel may help improve the clinical outcomes. However, based on the limited evidence, there is a need for randomized clinical trials in PAD patients to test both the effectiveness and safety outcomes of clopidogrel.

Comparison of Recent Practice Guidelines for the Management of Patients With Asymptomatic Carotid Stenosis

Despite the publication of several national/international guidelines, the optimal management of patients with asymptomatic carotid stenosis (AsxCS) remains controversial. This article compares 3 recently released guidelines (the 2020 German-Austrian, the 2021 European Stroke Organization [ESO], and the 2021 Society for Vascular Surgery [SVS] guidelines) vs the 2017 European Society for Vascular Surgery (ESVS) guidelines regarding the optimal management of AsxCS patients.The 2017 ESVS guidelines defined specific imaging/clinical parameters that may identify patient subgroups at high future stroke risk and recommended that carotid endarterectomy (CEA) should or carotid artery stenting (CAS) may be considered for these individuals. The 2020 German-Austrian guidelines provided similar recommendations with the 2017 ESVS Guidelines. The 2021 ESO Guidelines also recommended CEA for AsxCS patients at high risk for stroke on best medical treatment (BMT), but recommended against routine use of CAS in these patients. Finally, the SVS guidelines provided a strong recommendation for CEA+BMT vs BMT alone for low-surgical risk patients with >70% AsxCS. Thus, the ESVS, German-Austrian, and ESO guidelines concurred that all AsxCS patients should receive risk factor modification and BMT, but CEA should or CAS may also be considered for certain AsxCS patient subgroups at high risk for future ipsilateral ischemic stroke.

Pharmacogenetics of clopidogrel and warfarin in the treatment of cardiovascular diseases: an overview of reviews

Pharmacogenetics (PGx) is the relationship between an individual's genetic variations and the response to pharmacological treatment. We chose to perform an overview of reviews on PGx testing-guided treatment for cardiovascular diseases, based on clinically relevant gene-drug pairs. We conducted a search on Medline, Embase and Cochrane Library, from their inception to 18 June 2020. The most studied gene-drug pairs were clopidogrel and warfarin associated with cytochrome p450 and vitamin K epoxide reductase complex subunit 1 genes (CYP2C19, CYP2C9 and VKORC1), classified as critically low quality. There is a need for more quality primary studies and systematic reviews that assess the risk of bias, with consistent definitions of clinical outcomes to consider the benefits of PGx testing for cardiovascular diseases.

Relationship between platelet aggregation and stroke risk after percutaneous coronary intervention: a PENDULUM analysis

In patients undergoing percutaneous coronary intervention (PCI) with a stent, high on-treatment platelet reactivity may be associated with an increased risk of stroke. This post hoc analysis of the PENDULUM registry compared the risk of post-PCI stroke according to on-treatment P2Y₁₂ reaction unit (PRU) values. Patients aged ≥ 20 years who underwent PCI were stratified by baseline PRU (at 12 and 48 h post-PCI) as either high (HPR, > 208), optimal (OPR, > 85 to ≤ 208), or low on-treatment platelet reactivity (LPR, ≤ 85). The incidences of non-fatal ischemic and non-ischemic stroke through to 12 months post-PCI were recorded. Almost all enrolled patients (6102/6267 [97.4%]) had a risk factor for ischemic stroke, and most were receiving dual antiplatelet therapy. Of the 5906 patients with PRU data (HPR, n = 2227; OPR, n = 3002; LPR, n = 677), 47 had a non-fatal stroke post-PCI (cumulative incidence: 0.68%, ischemic; 0.18%, non-ischemic stroke). Patients with a non-fatal ischemic stroke event had statistically significantly higher post-PCI PRU values versus those without an event (P = 0.037). The incidence of non-fatal non-ischemic stroke was not related to PRU value. When the patients were stratified by PRU ≤ 153 versus > 153 at 12–48 h post-PCI, a significant difference was observed in the cumulative incidence of non-fatal stroke at 12 months (P = 0.044). We found that patients with ischemic stroke tended to have higher PRU values at 12–48 h after PCI versus those without ischemic stroke.

Clinical trial registration: UMIN000020332.

Diabetes and Outcomes Following Personalized Antiplatelet Therapy in Coronary Artery Disease Patients Who Have Undergone PCI

CONTEXT

A personalized antiplatelet therapy guided by a novel platelet function testing (PFT), PL-12, is considered an optimized treatment strategy in stable coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI). However, the safety and efficacy of any dual-antiplatelet therapy (DAPT) strategy may differ in relation to diabetes status.

OBJECTIVE

The aim of this study was to compare the outcomes of PFT-guided personalized DAPT in stable CAD patients with and without diabetes mellitus.

METHODS

The PATH-PCI trial randomly assigned 2285 stable CAD patients to either personalized antiplatelet therapy or standard antiplatelet treatment. We investigated the association and interaction of diabetes on clinical outcomes across 2 treatment groups.

RESULTS

We did not find a significant difference between the personalized group and the standard group in net adverse clinical events in either diabetes patients (10.3% vs 13.4%, P = .224) or in the nondiabetic group (3.1% vs 5.0%, P = .064). In diabetes patients (n = 646, 28.3%), the overall ischemic event rates were significantly low (6.8% vs 11.3%, HR = 0.586, 95% CI, 0.344-0.999, P = .049) and the bleeding event rates did not differ between the 2 groups (3.5% vs 3.3%, HR = 1.066, 95% CI, 0.462-2.458, P = .882). Similarly, in nondiabetic patients, the overall ischemic event rates were significantly low (1.8% vs 4.2%, HR = 0.428, 95% CI, 0.233-0.758, P = .006) and the bleeding event rates did not differ between the 2 groups (1.6% vs 0.9%, HR = 1.802, 95% CI: 0.719-4.516, P = .209).

CONCLUSION

The present study suggests that personalized antiplatelet therapy according to PFT can reduce ischemic events but not increase bleedings in stable CAD patients with or without diabetes who have undergone PCI.

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

BACKGROUND

Antiplatelet 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.

AIM

To 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.

METHODS

We conducted a meta-analysis with 72 selected studies from authentic databases, including 40,035 coronary artery disease patients treated with clopidogrel.

RESULTS

This 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).

CONCLUSION

Our 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.

Management of patients with asymptomatic carotid stenosis may need to be individualized: a multidisciplinary call for action. Republication of J Stroke 2021;23:202-212

The optimal management of patients with asymptomatic carotid stenosis (ACS) is the subject of extensive debate. According to the 2017 European Society for Vascular Surgery guidelines, carotid endarterectomy should (Class IIa; Level of Evidence: B) or carotid artery stenting may be considered (Class IIb; Level of Evidence: B) in the presence of one or more clinical/imaging characteristics that may be associated with an increased risk of late ipsilateral stroke (e.g. silent embolic infarcts on brain computed tomography/magnetic resonance imaging, progression in the severity of ACS, a history of contralateral transient ischemic attack/stroke, microemboli detection on transcranial Doppler, etc.), provided documented perioperative stroke/death rates are <3% and the patient's life expectancy is >5 years. Besides these clinical/imaging characteristics, there are additional individual, ethnic/racial or social factors that should probably be evaluated in the decision process regarding the optimal management of these patients, such as individual patient needs/patient choice, patient compliance with best medical treatment, patient sex, culture, race/ethnicity, age and comorbidities, as well as improvements in imaging/operative techniques/outcomes. The present multispecialty position paper will present the rationale why the management of patients with ACS may need to be individualized.

Biomarkers for Antiplatelet Therapies in Acute Ischemic Stroke: A Clinical Review

Stroke is one of the world's leading causes of disability and death. Antiplatelet agents are administered to acute ischemic stroke patients as secondary prevention. Clopidogrel involves biotransformation by cytochrome P450 (CYP) enzymes into an active metabolite, and single nucleotide polymorphisms (SNPs) can influence the efficacy of this biotransformation. Despite the therapeutic advantages of aspirin, there is significant inter-individual heterogeneity in response to this antiplatelet drug. In this clinical review, the recent advances in the biomarkers of antiplatelet agents in acute ischemic stroke are discussed. The studies reviewed herein highlight the clinical relevance of antiplatelet resistance, pharmacotherapy of antiplatelet agents predicting drug response, strategies for identifying aspirin resistance, pharmacogenetic variants of antiplatelet agents, miRNAs, and extracellular vesicles (EVs) as biomarkers toward the personalized approach in the management of acute ischemic stroke. The precise pathways contributing to antiplatelet resistance are not very well known but are presumably multi-factorial. It is essential to understand the clinical relevance of clopidogrel and aspirin-related single nucleotide polymorphism (SNPs) as potential predictive and prognostic biomarkers. Prasugrel is a next-generation antiplatelet agent that prevents ADP-platelet activation by binding irreversibly to P2Y12 receptor. There are sporadic reports of prasugrel resistance and polymorphisms in the Platelet endothelial aggregation receptor-1 (PEAR1) that may contribute to a change in the pharmacodynamics response. Ticagrelor, a direct-acting P2Y12-receptor antagonist, is easily absorbed and partly metabolized to major AR-C124910XX metabolite (ARC). Ticagrelor's primary active metabolite, ARC124910XX (ARC), is formed via the most abundant hepatic cytochrome P450 (CYP) enzyme, CYP3A4, and CYP3A5. The integration of specific biomarkers, genotype as well as phenotype-related data in antiplatelet therapy stratification in patients with acute ischemic stroke will be of great clinical significance and could be used as a guiding tool for more effective, personalized therapy.

Management of Patients with Asymptomatic Carotid Stenosis May Need to Be Individualized: A Multidisciplinary Call for Action

The optimal management of patients with asymptomatic carotid stenosis (ACS) is the subject of extensive debate. According to the 2017 European Society for Vascular Surgery guidelines, carotid endarterectomy should (Class IIa; Level of Evidence: B) or carotid artery stenting may be considered (Class IIb; Level of Evidence: B) in the presence of one or more clinical/imaging characteristics that may be associated with an increased risk of late ipsilateral stroke (e.g., silent embolic infarcts on brain computed tomography/magnetic resonance imaging, progression in the severity of ACS, a history of contralateral transient ischemic attack/stroke, microemboli detection on transcranial Doppler, etc.), provided documented perioperative stroke/death rates are <3% and the patient’s life expectancy is >5 years. Besides these clinical/imaging characteristics, there are additional individual, ethnic/racial or social factors that should probably be evaluated in the decision process regarding the optimal management of these patients, such as individual patient needs/patient choice, patient compliance with best medical treatment, patient sex, culture, race/ethnicity, age and comorbidities, as well as improvements in imaging/operative techniques/outcomes. The present multispecialty position paper will present the rationale why the management of patients with ACS may need to be individualized.