Effects of Triflusal and Clopidogrel on the Secondary Prevention of Stroke Based on Cytochrome P450 2C19 Genotyping

Cytochrome P450 2C19 Genotypes and Clopidogrel in Patients With Ischemic Stroke: A Nonrandomized Clinical Trial

Importance

Cytochrome P450 2C19 (CYP2C19) genotypes influence the antiplatelet effectiveness of clopidogrel by affecting its conversion to its active metabolite. However, evidence from prospective trials regarding the effects of CYP2C19 genotypes on the role of clopidogrel preventing cardiovascular events among patients with acute ischemic stroke remains limited.

Objective

To investigate the association of the CYP2C19 genotypes with the clinical prognosis of patients with acute ischemic stroke treated with clopidogrel.

Design, Setting, and Participants

A prospective, nonrandomized clinical trial was conducted from September 1, 2019, to January 27, 2023, at 37 clinical sites in South Korea. Patients who received clopidogrel within 72 hours of experiencing an acute ischemic stroke were included.

Interventions

Patients were classified using CYP2C19 genotyping into carrier and noncarrier of CYP2C19 loss-of-function (LOF) allele. Clopidogrel treatment was maintained throughout the study period.

Main Outcomes and Measures

The primary outcome was the difference in the risk of cardiovascular events (including ischemic or hemorrhagic stroke, myocardial infarction, or cardiovascular death) within 6 months after an ischemic stroke between patients who were carriers or noncarriers of the CYP2C19 LOF allele. The primary safety outcomes were the differences in all-cause mortality and the occurrence of major bleeding. Intention-to-treat analysis was performed.

Results

Overall, 2925 patients were enrolled in the PLATELET trial. The mean (SD) age of the participants was 65.3 (12.4) years, and 1928 (66.3%) were men. Among these patients, 15 were excluded. Of the remaining 2910 patients, 61.3% were classified as poor or intermediate metabolizers and 38.7% as extensive metabolizers. The primary outcome occurred more frequently in carriers of the LOF CYP2C19 allele than in noncarriers (2.7% [49 of 1785] vs 1.6% [18 of 1125]; log-rank P = .048). No significant differences were observed between CYP2C19 LOF allele carriers and noncarriers regarding the occurrence of major bleeding (0.6% [11 of 1785] vs 0.8% [9 of 1125]; P = .56) and all-cause mortality (0.3% [5] vs 0.1% [1]; P = .27).

Conclusions and Relevance

In this prospective nonrandomized clinical trial, carriers of the CYP2C19 LOF allele genotype exhibited a higher likelihood of experiencing cardiovascular events.

Trial Registration

ClinicalTrials.gov Identifier: NCT04072705.

Impact of CYP2C19 Genotype Status on Clinical Outcomes in Patients with Symptomatic Coronary Artery Disease, Stroke, and Peripheral Arterial Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Clopidogrel is widely used for the secondary prevention of atherothrombotic events in patients with coronary artery disease (CAD), ischemic stroke, and peripheral arterial disease (PAD). CYP2C19 plays a pivotal role in the conversion of clopidogrel to its active metabolite. Clopidogrel-treated carriers of a CYP2C19 loss-of-function allele (LOF) may have a higher risk of new atherothrombotic events. Previous studies on genotype-guided treatment were mainly performed in CAD and showed mixed results.

PURPOSE

To simultaneously investigate the impact of CYP2C19 genotype status on the rate of atherothrombotic events in the most common types of atherosclerotic disease (CAD, stroke, PAD).

METHODS

A comprehensive search in Pubmed, EMBASE, and MEDLINE from their inception to July 23rd 2023 was performed. Randomized controlled trials (RCTs) comparing genotype-guided and standard antithrombotic treatment, and cohort studies and post hoc analyses of RCTs concerning the association between CYP2C19 genotype status and clinical outcomes in clopidogrel-treated patients were included. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the safety end point major bleeding. Secondary endpoints were myocardial infarction, stent thrombosis, and ischemic stroke.

RESULTS

Forty-four studies were identified: 11 studies on CAD, 29 studies on stroke, and 4 studies on PAD. In CAD, genotype-guided therapy significantly reduced the risk of MACE [risk ratio (RR) 0.60, 95% confidence interval (CI) 0.43-0.83], myocardial infarction (RR 0.53, 95% CI 0.42-0.68), and stent thrombosis (RR 0.64, 95% CI 0.43-0.94), compared with standard antithrombotic treatment. The rate of major bleeding did not differ significantly (RR 0.93, 95% CI 0.70-1.23). Most RCTs were performed in patients after percutaneous coronary intervention (9/11). In stroke, LOF carriers had a significantly higher risk of MACE (RR 1.61, 95% CI 1.25-2.08) and recurrent ischemic stroke (RR 1.89, 95% CI 1.48-2.40) compared with non-carriers. No significant differences were found in major bleeding (RR 0.90, 95% CI 0.43-1.89). In the 6955 patients with symptomatic PAD treated with clopidogrel in the EUCLID trial, no differences in MACE or major bleeding were found between LOF carriers and non-carriers. In three smaller studies on patients with PAD treated with clopidogrel after endovascular therapy, CYP2C19 genotype status was significantly associated with atherothrombotic events.

CONCLUSIONS

Genotype-guided treatment significantly decreased the rate of atherothrombotic events in patients with CAD, especially after PCI. In patients with history of stroke, LOF carriers treated with clopidogrel had a higher risk of MACE and recurrent stroke. The available evidence in PAD with regard to major adverse limb events is too limited to draw meaningful conclusions.

REGISTRATION

PROSPERO identifier no. CRD42020220284.

Clinical and cost-effectiveness of clopidogrel resistance genotype testing after ischaemic stroke or transient ischaemic attack: a systematic review and economic model

Background

Stroke or transient ischaemic attack patients are at increased risk of secondary vascular events. Antiplatelet medications, most commonly clopidogrel, are prescribed to reduce this risk. Factors including CYP2C19 genetic variants can hinder clopidogrel metabolism. Laboratory-based or point-of-care tests can detect these variants, enabling targeted treatment.

Objective

To assess the effectiveness of genetic testing to identify clopidogrel resistance in people with ischaemic stroke or transient ischaemic attack. Specific objectives: Do people tested for clopidogrel resistance, and treated accordingly, have a reduced risk of secondary vascular events? Do people with loss-of-function alleles associated with clopidogrel resistance have a reduced risk of secondary vascular events if treated with alternative interventions compared to clopidogrel? Do people with loss-of-function alleles associated with clopidogrel resistance have an increased risk of secondary vascular events when treated with clopidogrel? What is the accuracy of point-of-care tests for detecting variants associated with clopidogrel resistance? What is the technical performance and cost of CYP2C19 genetic tests? Is genetic testing for clopidogrel resistance cost-effective compared with no testing?

Design

Systematic review and economic model.

Results

Objective 1: Two studies assessed secondary vascular events in patients tested for loss-of-function alleles and treated accordingly. They found a reduced risk, but confidence intervals were wide (hazard ratio 0.50, 95% confidence interval 0.09 to 2.74 and hazard ratio 0.53, 95% confidence interval 0.24 to 1.18). Objective 2: Seven randomised controlled trials compared clopidogrel with alternative treatment in people with genetic variants. Ticagrelor was associated with a lower risk of secondary vascular events than clopidogrel (summary hazard ratio 0.76, 95% confidence interval 0.65 to 0.90; two studies). Objective 3: Twenty-five studies compared outcomes in people with and without genetic variants treated with clopidogrel. People with genetic variants were at an increased risk of secondary vascular events (hazard ratio 1.72, 95% confidence interval 1.43 to 2.08; 18 studies). There was no difference in bleeding risk (hazard ratio 0.98, 95% confidence interval 0.68 to 1.40; five studies). Objective 4: Eleven studies evaluated Genomadix Cube accuracy; no studies evaluated Genedrive. Summary sensitivity and specificity against laboratory reference standards were both 100% (95% confidence interval 94% to 100% and 99% to 100%). Objective 5: Seventeen studies evaluated technical performance of point-of-care tests. Test failure rate ranged from 0.4% to 19% for Genomadix Cube. A survey of 8/10 genomic laboratory hubs revealed variation in preferred technologies for testing, and cost per test ranging from £15 to £250. Most laboratories expected test failure rate to be < 1%. Additional resources could enhance testing capacity and expedite turnaround times. Objective 6: Laboratory and point-of-care CYP2C19 testing strategies were cost-saving and increase quality-adjusted life-years compared with no testing. Both strategies gave similar costs, quality-adjusted life-years and expected net monetary benefit.

Conclusions

Our results suggest that CYP2C19 testing followed by tailored treatment is likely to be effective and cost-effective in both populations.

Future work

Accuracy and technical performance of Genedrive. Test failure rate of Genomadix Cube in a National Health Service setting. Value of testing additional loss-of-function alleles. Appropriateness of treatment dichotomy based on loss-of-function alleles.

Limitations

Lack of data on Genedrive. No randomised 'test-and-treat' studies of dipyramidole plus aspirin.

Study registration

This study is registered as PROSPERO CRD42022357661.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Evidence Synthesis programme (NIHR award ref: NIHR135620) and is published in full in Health Technology Assessment; Vol. 28, No. 57. See the NIHR Funding and Awards website for further award information.

The association of CYP2C19 LoF alleles with adverse clinical outcomes in stroke patients taking clopidogrel: An updated meta-analysis

The aggregated risk of recurrent stroke in stroke/transient ischemic attack (TIA) patients carrying CYP2C19 LoF alleles who take clopidogrel has not been investigated recently, and the available research is limited. This study aimed to perform an updated meta-analysis to assess the association between CYP2C19 LoF alleles and the risk of recurrent stroke in patients taking clopidogrel. Databases were searched for the literature on eligible studies. The end points were recurrent stroke, composite vascular events, and bleeding events. Odds ratios (ORs) were calculated using RevMan software, where p < 0.05 was considered statistically significant. Patients carrying CYP2C19 LoF alleles who were treated with clopidogrel had a significantly increased risk of recurrent ischemic stroke compared with non-carriers (OR 2.18, 96% CI 1.80-2.63; p < 0.00001). The risk of recurrent stroke was only significantly different in Asian patients (OR 2.29, 96% CI 1.88-2.80; p < 0.00001) but not in patients of other ethnicities; however, there were a limited number of studies in other ethnic groups. Both observational studies (OR 2.83, 96% CI 2.20-3.65; p < 0.00001) and RCTs (OR 1.48, 96% CI 1.10-1.98; p = 0.009) found associations with a significantly increased risk of recurrent ischemic stroke. Asian stroke patients or TIA patients carrying CYP2C19 LoF alleles and taking clopidogrel were at a significantly higher risk of recurrent ischemic stroke than non-carriers. Significantly increased risk of recurrent ischemic stroke was found in both observational studies and RCTs.

European stroke organisation (ESO) guideline on cerebral small vessel disease, part 2, lacunar ischaemic stroke

A quarter of ischaemic strokes are lacunar subtype, typically neurologically mild, usually resulting from intrinsic cerebral small vessel pathology, with risk factor profiles and outcome rates differing from other stroke subtypes. This European Stroke Organisation (ESO) guideline provides evidence-based recommendations to assist with clinical decisions about management of lacunar ischaemic stroke to prevent adverse clinical outcomes. The guideline was developed according to ESO standard operating procedures and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. We addressed acute treatment (including progressive lacunar stroke) and secondary prevention in lacunar ischaemic stroke, and prioritised the interventions of thrombolysis, antiplatelet drugs, blood pressure lowering, lipid lowering, lifestyle, and other interventions and their potential effects on the clinical outcomes recurrent stroke, dependency, major adverse cardiovascular events, death, cognitive decline, mobility, gait, or mood disorders. We systematically reviewed the literature, assessed the evidence and where feasible formulated evidence-based recommendations, and expert concensus statements. We found little direct evidence, mostly of low quality. We recommend that patients with suspected acute lacunar ischaemic stroke receive intravenous alteplase, antiplatelet drugs and avoid blood pressure lowering according to current acute ischaemic stroke guidelines. For secondary prevention, we recommend single antiplatelet treatment long-term, blood pressure control, and lipid lowering according to current guidelines. We recommend smoking cessation, regular exercise, other healthy lifestyle modifications, and avoid obesity for general health benefits. We cannot make any recommendation concerning progressive stroke or other drugs. Large randomised controlled trials with clinically important endpoints, including cognitive endpoints, are a priority for lacunar ischaemic stroke.

R558C NOTCH3 Mutation in a CADASIL Patient with Intracerebral Hemorrhage: A Case Report with Literature Review

BACKGROUND

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a monogenic cerebral small-vessel disease, which is characterized by migraine, recurrent ischemic strokes, psychiatric disorder, progressive cognitive decline, and occasionally intracerebral hemorrhage (ICH). ICH events have been reported in a high proportion of East Asian CADASIL patients with R544C mutation in exon 11 of NOTCH3; however, whether any other specific NOTCH3 mutation determines the ICH phenotype has yet to be explored.

CASE PRESENTATION

We report the case of a 60-year-old male CADASIL patient with a novel R558C mutation in exon 11 of the NOTCH3 gene, who presented with ICH in the basal ganglia and cerebellum. Brain imaging revealed multiple confluent white matter hyperintensities and abundant cerebral microbleeds (CMBs) in the bilateral basal ganglia, thalamus, and cerebellum. The patient had been having recurrent ischemic strokes prior to this ICH event, and had taken antiplatelet and antihypertensive agents for six months. We analyzed the possible reasons for ICH onset in the patient to recommend certain guidelines for the clinic.

CONCLUSIONS

Novel R558C mutation-related CADASIL vasculopathy and numerous CMBs, uncontrolled hypertension, and antiplatelet therapy could collectively contribute to ICH onset in the patient with CADASIL. These findings suggest that a diagnosis of CADASIL should also be considered when patients present with ICH, whenever MRI imaging reveals typical white matter abnormalities. Furthermore, this case report emphasizes the importance of CMB assessment, appropriate blood pressure control, and cautious assessment of the risk-benefits of antiplatelet medication in patients with CADASIL.

Antiplatelet regimens after ischemic stroke or transient ischemic attack: a systematic review and updated network meta-analysis

Background

It is still uncertain which antiplatelet regimen had the greatest net clinical benefit in patients who have suffered a transient ischemic attack or non-cardioembolic ischemic stroke, and it is necessary to choose the optimal regimen according to the clinical situation.

Methods

We utilized 3 databases of Medline, Embase, and the Cochrane Central Register of Controlled Trials to find randomized controlled trials that met our criteria, and performed network meta-analyses in recurrent stroke, composite outcomes, major bleeding events, recurrent ischemic stroke, and all bleeding events. Three-dimensional clustered rank plots were used to obtain the net clinical benefit. Subgroup analyses were performed according to the symptom-onset-to-treatment time (<72 and >72 h), stroke subtypes (large artery atherosclerosis and small vessel occlusion), and dual antiplatelet agent treatment duration.

Results

A total of 69 trials were enrolled. Cilostazol was associated with a lower risk of recurrent stroke, major bleeding events, composite outcomes, recurrent ischemic stroke, and all bleeding events compared to low to medium dose aspirin. The three-dimensional rank plot showed that cilostazol had the highest net clinical benefit. The combination of aspirin plus clopidogrel had greater efficacy in the <72 h after stroke onset and large artery atherosclerosis subgroups, and when it was restricted to1 month of use major bleeding risk was not higher than aspirin. The combination of aspirin plus dipyridamole had greater efficacy and safety comparable to aspirin in terms of small vessel occlusion.

Conclusions

The efficacy and safety profiles among antiplatelet regimens may differ according to clinical situation, although cilostazol, aspirin plus clopidogrel, and aspirin plus dipyridamole may be considered as preferable options.

The Dynamic Effect of Non-CYP3A4-Metabolized and CYP3A4-Metabolized Statins on Clopidogrel Resistance in Patients With Cerebral Infarction

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.

Antiplatelet regimens for Asian patients with ischemic stroke or transient ischemic attack: a systematic review and network meta-analysis

BACKGROUND

The optimal antiplatelet treatment for the secondary prevention of non-cardioembolic stroke or transient ischemic attack (TIA) remains uncertain in Asians.

METHODS

We searched for eligible randomized control trials in Medline, Embase, and the Cochrane Library. A Bayesian network meta-analysis (NMA) was performed to assess the efficacy and safety of antiplatelet regimens with placebo as the control. Each therapy was compared using relative risk ratios (RR) and 95% credible intervals (CrI), and ranked according to the value of the surface under the cumulative ranking curve.

RESULTS

A total of 84,103 patients from 32 studies were included: patients in used aspirin (n=26,834); cilostazol (n=3,303); clopidogrel (n=12,406); prasugrel (n=1,885); sarpogrelate (n=752); ticagrelor (n=1,933); ticlopidine (n=1,644); triflusal (n=391); aspirin plus cilostazol (n=1,120), aspirin plus clopidogrel (n=4,623); aspirin plus dipyridamole (n=10,853); aspirin plus ticagrelor (n=5,859); aspirin plus ticlopidine (n=132). Patients who used aspirin plus clopidogrel and cilostazol had a lower risk of recurrent stroke than those who used placebo. Patients administered with aspirin plus ticagrelor, aspirin plus clopidogrel, and cilostazol had a lower risk of composite vascular events than those administered placebo. Patients administered aspirin plus ticagrelor had a higher risk of major bleeding than those administered placebo. Clustered three-dimensional rank plots of recurrent stroke, major bleeding, and composite vascular events demonstrated that cilostazol had higher values of the surface under the cumulative ranking curve than other treatments.

CONCLUSIONS

Of the antiplatelet regimens, cilostazol showed the best net clinical benefits than other antiplatelet regimens in Asians with non-cardioembolic stroke or TIA.

Association with CYP2C19 polymorphisms and Clopidogrel in treatment of elderly stroke patients

BACKGROUND

Clopidogrel is an antiplatelet drug used in the treatment of ischemic stroke. Safety and efficacy of clopidogrel has been confirmed in CAPRIE, PRoFESS trials. However, these studies focused on patients aged less than 75 years. CYP2C19 polymorphisms resulted in individual differences in clopidogrel response. Our objective was to determine whether elderly stroke patients aged over 75 years would benefit from CYP2C19-genotype-guided strategy for the secondary prevention of stroke.

METHODS

A retrospective analysis of patients aged 75 years or older with non-cardiogenic stroke who received 75 mg clopidogrel was performed. CYP2C19 genotype-guided group included noncarriers of CYP2C19*2 or CYP2C19*3 loss-of-function alleles (LoFA) and compared against the non-genotype-guided group which may carriers CYP2C19 LoFA or not. The primary endpoints were composite of stroke and myocardial infarction at 24 months' follow-up.

RESULTS

Two hundred one patients were included: 99 in the genotype-guided group and 102 in the non-genotype-guided group. Kaplan-Meier(KM)analysis showed that CYP2C19 gene polymorphism was associated with the rate of the primary endpoints (P = 0.0031). The primary endpoints occurred in 13 patients (13.1%) in the genotype-guided group and in 30 patients (29.4%) in the non-genotype-guided group (hazard ratio(HR), 0.39; 95% confidence interval(CI), 0.20 to 0.75; p = 0.004). Cox regression analysis showed that CYP2C19 genotype-guided strategy was a protective factor for the primary endpoints (HR, 0.39; 95% CI:0.20 to 0.74, P = 0.004).

CONCLUSION

The CYP2C19 genotype-guided strategy could reduce the occurrence of composite of stroke and myocardial infarction compared to a non-genotype-guided strategy for non-cardiogenic stroke patients aged 75 years or older who received clopidogrel.

Clopidogrel preventive effect based on cytochrome P450 2C19 genotype in ischaemic stroke: protocol for multicentre observational study

INTRODUCTION

Clopidogrel is an antiplatelet agent that is widely used for the secondary prevention of cardiovascular and cerebrovascular events. The genotype of cytochrome P450 2C19 (CYP2C19) differentially affects the liver's metabolism of clopidogrel, which may influence the drug's response and efficacy for cardiovascular event prevention. In contrast to prior studies of patients with coronary artery diseases, little is known about whether the CYP2C19 genotype influences the preventive efficacy of clopidogrel in patients who had a stroke. We hypothesise that, among patients who had an acute ischaemic stroke who are prescribed clopidogrel, the patients with a loss-of-function CYP2C19 genotype (poor and intermediate metabolisers) may be at a higher risk of composite cardiovascular events than those who are non-carriers (extensive metabolisers).

METHODS AND ANALYSIS

This prospective observational multicentre study was designed to determine whether composite cardiovascular events would differ among patients who had an ischaemic stroke prescribed clopidogrel according to CYP2C19 genotype (poor or intermediate vs extensive metabolisers). Inclusion criteria were patients who had an acute ischaemic stroke who underwent CYP2C19 genotype evaluation and received clopidogrel within 72 hours of stroke onset. The primary outcome is composite cardiovascular events (stroke, myocardial infarction, or cardiovascular death) within 6 months after acute ischaemic stroke between patients categorised as poor or intermediate metabolisers and those categorised as extensive metabolisers according to their CYP2C19 genotype.

ETHICS AND DISSEMINATION

The Institutional Review Board of Severance Hospital, Yonsei University College of Medicine approved this study (3-2019-0195). We received study approval from the institutional review board of each participating hospital. We plan to disseminate our findings at relevant conferences and meetings and through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04072705.

The correlation between recurrent risk and CYP2C19 gene polymorphisms in patients with ischemic stroke treated with clopidogrel for prevention

BACKGROUND

To explore the correlation between recurrent risk and CYP2C19 gene polymorphisms in patients with ischemic stroke (IS) treated with clopidogrel for prevention.

METHODS

A total of 289 patients with IS treated with clopidogrel regularly were enrolled in this study, and stroke recurrence of all patients were recorded by follow-up. The correlation between CYP2C19 gene polymorphism and stroke recurrence in patients taking clopidogrel regularly was analyzed.

RESULTS

After a mean follow-up period of 6 months, there were 289 patients who took clopidogrel regularly, and 41 of which occurred recurrent stroke. Patients of poor metabolizer and intermediate metabolizer had higher risk of recurrent stroke comparing with patients of extensive metabolize, and the odds ratios were 2.88 (95% confidence interval [CI] 1.31-6.33, P = .068) and 3.00 (95% CI 1.09-8.22, P = .027), respectively. The recurrence risk of *2 (G681A)A allele carriers was 3.30 times that of G allele carriers (P = .0065). The recurrence rate of stroke in patients carrying heterozygous and homozygous *2 allele mutant was 1.96 times (P = .071) and 3.30 times (P = .012) that of patients with wild-type genes. Multifactor logistic regression analysis result indicated carrying loss of function (LOF) allele was an independent risk factor of stroke recurrence.

CONCLUSION

For patients with IS treated with clopidogrel regularly for secondary prevention, poor metabolizer, and intermediate metabolizer patients had higher risk of recurrent stroke comparing with extensive metabolize ones. Carrying CYP2C19 LOF allele is an independent risk factor of stroke recurrence in patients with IS.