Time Course for Benefit and Risk With Ticagrelor and Aspirin in Individuals With Acute Ischemic Stroke or Transient Ischemic Attack Who Carry CYP2C19 Loss-of-Function Alleles: A Secondary Analysis of the CHANCE-2 Randomized Clinical Trial

Duration of Benefit and Risk of Dual Antiplatelet Therapy up to 72 Hours After Mild Ischemic Stroke and Transient Ischemic Attack

BACKGROUND AND OBJECTIVES

Clopidogrel-aspirin initiated within 72 hours of symptom onset is effective in patients with mild ischemic stroke or transient ischemic attack (TIA) in the Intensive Statin and Antiplatelet Therapy for Acute High-risk Intracranial or Extracranial Atherosclerosis (INSPIRES) trial. Uncertainties remain about the duration of the treatment effect. This study aimed to assess duration of benefit and risk of clopidogrel-aspirin in these patients.

METHODS

The INSPIRES trial was a 2*2 factorial placebo-controlled randomized trial conducted in 222 hospitals in China. The 2 treatments did not interact and were evaluated separately. In this study, we performed secondary analyses based on antiplatelet treatment. All patients with mild stroke or TIA of presumed atherosclerotic cause within 72 hours of symptom onset enrolled in the trial were included. Patients were randomly assigned to receive clopidogrel-aspirin on days 1-21 followed by clopidogrel on days 22-90 or aspirin alone for 90 days. The primary efficacy outcome was major ischemic event which included the composite of ischemic stroke and nonhemorrhagic death. The primary safety outcome was moderate-to-severe bleeding. We estimated the risk difference between the 2 treatments for each stratified week.

RESULTS

All 6,100 patients in the trial were included (3,050 in each group). The mean age was 65 years, and 3,915 patients (64.2%) were men. Compared with aspirin alone, the reduction of major ischemic events by clopidogrel-aspirin mainly occurred in the first week (absolute risk reduction [ARR] 1.42%, 95% CI 0.53%-2.32%) and remained in the second week (ARR 0.49%, 95% CI 0.09%-0.90%) and the third week (ARR 0.29%, 95% CI -0.05% to 0.62%). Numerical higher risk of moderate-to-severe bleedings in the clopidogrel-aspirin group was observed in the first 3 weeks (absolute risk increase 0.05% [95% CI -0.10% to 0.20%], 0.10% [95% CI -0.09% to 0.29%], and 0.18% [95% CI -0.03% to 0.40%] in the first, second, and third weeks, respectively).

CONCLUSIONS

Among patients with mild ischemic stroke or high-risk TIA of presumed atherosclerotic cause, the net benefit of clopidogrel-aspirin initiated within 72 hours of symptom onset was pronounced in the first week and continued to a lesser degree in the following 2 weeks, outweighing the low, but ongoing hemorrhagic risk.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT03635749.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that among patients with mild ischemic stroke or high-risk TIA of presumed atherosclerotic cause, the net benefit of clopidogrel-aspirin initiated within 72 hours of symptom onset was pronounced in the first week and continued to a lesser degree in the following 2 weeks, outweighing the low but ongoing hemorrhagic risk.

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.

Association of clopidogrel resistance and ABCD-GENE score with long-term clinical prognosis in patients with ischemic stroke or TIA

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.

Stroke

Stroke affects up to one in five people during their lifetime in some high-income countries, and up to almost one in two in low-income countries. Globally, it is the second leading cause of death. Clinically, the disease is characterised by sudden neurological deficits. Vascular aetiologies contribute to the most common causes of ischaemic stroke, including large artery disease, cardioembolism, and small vessel disease. Small vessel disease is also the most frequent cause of intracerebral haemorrhage, followed by macrovascular causes. For acute ischaemic stroke, multimodal CT or MRI reveal infarct core, ischaemic penumbra, and site of vascular occlusion. For intracerebral haemorrhage, neuroimaging identifies early radiological markers of haematoma expansion and probable underlying cause. For intravenous thrombolysis in ischaemic stroke, tenecteplase is now a safe and effective alternative to alteplase. In patients with strokes caused by large vessel occlusion, the indications for endovascular thrombectomy have been extended to include larger core infarcts and basilar artery occlusion, and the treatment time window has increased to up to 24 h from stroke onset. Regarding intracerebral haemorrhage, prompt delivery of bundled care consisting of immediate anticoagulation reversal, simultaneous blood pressure lowering, and prespecified stroke unit protocols can improve clinical outcomes. Guided by underlying stroke mechanisms, secondary prevention encompasses pharmacological, vascular, or endovascular interventions and lifestyle modifications.

Colchicine in patients with acute ischaemic stroke or transient ischaemic attack (CHANCE-3): multicentre, double blind, randomised, placebo controlled trial

OBJECTIVES

To assess the efficacy and safety of colchicine versus placebo on reducing the risk of subsequent stroke after high risk non-cardioembolic ischaemic stroke or transient ischaemic attack within the first three months of symptom onset (CHANCE-3).

DESIGN

Multicentre, double blind, randomised, placebo controlled trial.

SETTING

244 hospitals in China between 11 August 2022 and 13 April 2023.

PARTICIPANTS

8343 patients aged 40 years of age or older with a minor-to-moderate ischaemic stroke or transient ischaemic attack and a high sensitivity C-reactive protein ≥2 mg/L were enrolled.

INTERVENTIONS

Patients were randomly assigned 1:1 within 24 h of symptom onset to receive colchicine (0.5 mg twice daily on days 1-3, followed by 0.5 mg daily thereafter) or placebo for 90 days.

MAIN OUTCOME MEASURES

The primary efficacy outcome was any new stroke within 90 days after randomisation. The primary safety outcome was any serious adverse event during the treatment period. All efficacy and safety analyses were by intention to treat.

RESULTS

4176 patients were assigned to the colchicine group and 4167 were assigned to the placebo group. Stroke occurred within 90 days in 264 patients (6.3%) in the colchicine group and 270 patients (6.5%) in the placebo group (hazard ratio 0.98 (95% confidence interval 0.83 to 1.16); P=0.79). Any serious adverse event was observed in 91 (2.2%) patients in the colchicine group and 88 (2.1%) in the placebo group (P=0.83).

CONCLUSIONS

The study did not provide evidence that low-dose colchicine could reduce the risk of subsequent stroke within 90 days as compared with placebo among patients with acute non-cardioembolic minor-to-moderate ischaemic stroke or transient ischaemic attack and a high sensitivity C-reactive protein ≥2 mg/L.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05439356.

Role of residential greenspace in the trajectory of major neurological disorders: A longitudinal study in UK Biobank

BACKGROUND

Stroke and dementia are major neurological disorders that contribute significantly to disease burden and are interlinked in terms of risk. Nevertheless, there is currently no study investigating the influence of residential greenspace on the trajectory of these neurological disorders.

METHODS

This longitudinal study utilized data from the UK Biobank. Exposure to residential greenspace was measured by the percentage of total greenspace coverage within a 300-meter buffer zone surrounding the participants' residences. A multistate model was employed to illustrate the trajectory of major neurological disorders, and a piecewise Cox regression model was applied to explore the impact of residential greenspace on different time courses of disease transitions.

RESULTS

With 422,649 participants and a median follow-up period of 12.5 years, 8568 (2.0 %), 5648 (1.3 %), and 621 (0.1 %) individuals developed incident stroke, dementia, and comorbidity of both conditions, respectively. An increase in residential greenspace by one interquartile range was associated with reduced risks of transitions from baseline to stroke, dementia, and death, as well as from stroke to comorbidity. The corresponding hazard ratios (HRs) were 0.967 (95 % CI: 0.936, 0.998), 0.928 (0.892, 0.965), 0.925 (0.907, 0.942), and 0.799 (0.685, 0.933), respectively. Furthermore, the protective effect of residential greenspace on the transition from stroke or dementia to comorbidity was particularly pronounced within the first year and over 5 years after stroke and during the 2 to 3 years after dementia onset, with HRs of 0.692 (0.509, 0.941), 0.705 (0.542, 0.918), and 0.567 (0.339, 0.949), respectively.

CONCLUSION

This study observed a protective role of residential greenspace in the trajectory of major neurological disorders and contributed to identifying critical progression windows. These findings underscore the significance of environment-health interactions in the prevention of neurological disorders.

Spatial and temporal mapping of neuron-microglia interaction modes in acute ischemic stroke

Ischemic stroke (IS) is a major cause of morbidity and mortality worldwide, accounting for 75-80% of all strokes. Under conditions of ischemia and hypoxia, neurons suffer damage or death, leading to a series of secondary immune reactions. Microglia, the earliest activated immune cells, can exert neurotoxic or neuroprotective effects on neurons through secretion of factors. There exists a complex interaction between neurons and microglia during this process. Moreover, the interaction between them becomes even more complex due to differences in the infarct area and reperfusion time. This review first elaborates on the differences in neuronal death modes between the ischemic core and penumbra, and then introduces the differences in microglial markers across different infarct areas with varying reperfusion time, indicating distinct functions. Finally, we focus on exploring the interaction modes between neurons and microglia in order to precisely target beneficial interactions and inhibit harmful ones, thus providing new therapeutic strategies for the treatment of IS.

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.

The Frequency of CYP2C19 Loss-of-Function Variants in Patients with Non-Cardioembolic Ischemic Stroke or Transient Ischemic Attack in the Dutch Population

INTRODUCTION

The CYP2C19 enzyme converts clopidogrel into an active metabolite. Carriers of CYP2C19 loss-of-function (LOF) variants with a history of ischemic stroke or transient ischemic attack (TIA) using clopidogrel may have a higher risk of recurrent stroke. To study the implications of genetic CYP2C19 heterogeneity in treatment of cerebral ischemia, knowledge about the prevalence of CYP2C19 LOF variants within the population is important. We investigated the frequency of CYP2C19 LOF variants in patients with non-cardioembolic ischemic stroke or TIA in the Dutch population.

METHODS

We performed a single-center observational study with a cross-sectional design in a Dutch thrombectomy-capable stroke center. We included all patients presenting with non-cardioembolic ischemic stroke or TIA. We determined the frequency of CYP2C19 LOF variants in the full cohort. Additionally, we compared the frequency of CYP2C19 LOF variants in two subgroups: patients with first-ever non-cardioembolic ischemic stroke or TIA versus patients with recurrent ischemic stroke or TIA using clopidogrel because of a history of ischemic stroke or TIA.

RESULTS

We enrolled 410 patients between January 1, 2021, and July 1, 2021. 109 (26.6%) patients were carriers of CYP2C19 LOF variants. We found no difference in the frequency of CYP2C19 LOF variants between patients with first-ever ischemic stroke or TIA versus patients with recurrent ischemic stroke or TIA using clopidogrel (25.9 vs. 31.9%, respectively, p = 0.31).

DISCUSSION AND CONCLUSION

About a quarter of patients with non-cardioembolic ischemic stroke or TIA in the Dutch population carry a CYP2C19 LOF variant. This is lower than estimates found in studies with Asian populations but similar to estimates found among Caucasian patients in other parts of the world.

DNA methylation profile in the whole blood of acute coronary syndrome patients with aspirin resistance

BACKGROUND

Aspirin resistance (AR) results in major adverse cardiovascular events, and DNA methylation might participate in the regulation of this pathological process.

METHODS

In present study, a sum of 35 patients with AR and 35 non-AR (NAR) controls were enrolled. Samples from 5 AR and 5 NAR were evaluated in an 850 BeadChip DNA methylation assay, and another 30 AR versus 30 NAR were evaluated to validate the differentially methylated CpG loci (DML). Then, qRT-PCR was used to investigate the target mRNA expression of genes at CpG loci. Finally, Gene Ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to reveal the enriched pathways.

RESULTS

The AR and NAR groups displayed significant differences in DNA methylation at 7707 positions, with 270 hypermethylated sites (e.g., cg09555818 located in APOC2) and 7437 sites hypomethylated sites (e.g., cg26828689 located in SLC12A5). Six DML were validated by pyrosequencing, and it was confirmed that DNA methylation (cg16391727, cg21008208, cg21293749, and cg13945576) was related to the increasing risk of AR. The relative mRNA expression of the ROR1 gene was also associated with AR (p = 0.007), suggesting that the change of cg21293749 in DNA methylation might lead to differential ROR1 mRNA expression, ultimately resulting in AR. Furthermore, the identified differentially methylated sites were associated with the molecular pathways such as circadian rhythms and insulin secretion.

CONCLUSION

Hence, the distinct DNA methylation might play a vital role in the biological regulation of AR through the pathways such as circadian rhythms.

Navigating Antiplatelet Treatment Options for Stroke: Evidence-Based and Pragmatic Strategies

PURPOSE OF REVIEW

The benefit of using antiplatelet monotherapy in acute ischemic stroke and secondary stroke prevention is well established. In the last few years, several large randomized trials showed that the use of short-term dual antiplatelet therapy in particular stroke subtypes may reduce the risk of recurrent ischemic events. The aim of this article is to provide a critical analysis of the current evidence and recommendations for the use of antiplatelet agents for stroke prevention.

RECENT FINDINGS

Long-term therapy with aspirin, clopidogrel, or aspirin plus extended-release dipyridamole is recommended for secondary stroke prevention in patients with noncardioembolic ischemic stroke. Short-term dual antiplatelet therapy with aspirin and clopidogrel is superior to antiplatelet monotherapy in secondary stroke prevention when used in patients with mild noncardioembolic stroke or high-risk transient ischemic attack. Dual therapy, however, is associated with an increased risk of major bleeding, particularly when the treatment is extended for greater than 30 days. Similarly, aspirin plus ticagrelor is superior to aspirin monotherapy for the prevention of recurrent ischemic stroke, although this combination is associated with a higher risk of hemorrhagic complications when compared to other dual antiplatelet regimens. Among patients who carry CYP2C19 genetic polymorphisms associated with a slow bioactivation of clopidogrel, short-term treatment with aspirin plus ticagrelor is superior to aspirin plus clopidogrel for the reduction of recurrent stroke; however, the use of ticagrelor is associated with a higher risk of any bleeding. In patients with symptomatic intracranial stenosis, aggressive medical management in addition to dual antiplatelet therapy up to 90 days is recommended. Antiplatelet therapy has an essential role in the management of ischemic stroke. The specific antiplatelet regimen should be individualized based on the stroke characteristics, time from symptom onset, and patient-specific predisposition to develop hemorrhagic complications.