Ticagrelor in Acute Stroke or Transient Ischemic Attack in Asian Patients: From the SOCRATES Trial (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes)

Quantitative evaluation of CTP derived time-density alterations versus CTP for collateral status prediction with stroke

BACKGROUND AND OBJECTIVES

Collateral status is a pivotal determinant of clinical outcomes in acute ischemic stroke (AIS); however, its evaluation can be challenging. We investigated the predictive value of CT perfusion (CTP) derived time and density alterations versus CTP for collateral status prediction in AIS.

METHODS

Consecutive patients with anterior circulation occlusion within 24 h were retrospectively included. Time-density curves of the CTP specified ischemic core, penumbra, and the corresponding contralateral unaffected brain were obtained. The collateral status was dichotomised into robust (4-5 scores) and poor (0-3 scores) using multiphase collateral scoring, as described by Menon et al.. Receiver operating characteristic curves and multivariable regression analysis were performed to assess the predictive ability of CTP-designated tissue time and density alterations, CTP for robust collaterals, and favourable outcomes (mRS score of 0-2 at 90 days).

RESULTS

One-hundred patients (median age, 68 years; interquartile range, 57-80 years; 61 men) were included. A smaller ischemic core, shorter peak time delay, lower peak density decrease, lower cerebral blood volume ratio, and cerebral blood flow ratio in the CTP specified ischemic core were significantly associated with robust collaterals (PFDR ≤ 0.004). The peak time delay demonstrated the highest diagnostic value (AUC, 0.74; P < 0.001) with 66.7 % sensitivity and 73.7 % specificity. Furthermore, the peak time delay of less than 8.5 s was an independent predictor of robust collaterals and favourable clinical outcomes.

CONCLUSIONS

Robust collateral status was significantly associated with the peak time delay in the ischemic core. It is a promising image marker for predicting collateral status and functional outcomes in AIS.

A Bayesian approach based on discounting factor for consistency assessment in multi-regional clinical trial

Multi-regional clinical trial (MRCT) has become an increasing trend for its supporting simultaneous global drug development. After MRCT, consistency assessment needs to be conducted to evaluate regional efficacy. The weighted Z-test approach is a common consistency assessment approach in which the weighting parameter W does not have a good practical significance; the discounting factor approach improved from the weighted Z-test approach by converting the estimation of W in original weighted Z-test approach to the estimation of discounting factor D. However, the discounting factor approach is an approach of frequency statistics, in which D was fixed as a certain value; the variation of D was not considered, which may lead to un-reasonable results. In this paper, we proposed a Bayesian approach based on D to evaluate the treatment effect for the target region in MRCT, in which the variation of D was considered. Specifically, we first took D random instead of fixed as a certain value and specified a beta distribution for it. According to the results of simulation, we further adjusted the Bayesian approach. The application of the proposed approach was illustrated by Markov Chain Monte Carlo simulation.

Dual Antiplatelet Therapies and Causes in Minor Stroke or Transient Ischemic Attack: A Prespecified Analysis in the CHANCE-2 Trial

BACKGROUND

It is unclear whether patients with different stroke/transient ischemic attack etiologies benefit differently from gene-directed dual antiplatelet therapy. This study explored the efficacy and safety of ticagrelor-aspirin versus clopidogrel-aspirin in transient ischemic attack or minor stroke with different causes in the CHANCE-2 trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events-II).

METHODS

This was a prespecified analysis of the CHANCE-2 trial, which enrolled 6412 patients with minor stroke or transient ischemic attack who carried CYP2C19 loss-of-function alleles. Patients with centralized evaluation of TOAST (Trial of ORG 10172 in Acute Stroke Treatment) classification of large-artery atherosclerosis, small-vessel occlusion, and stroke of undetermined cause were included. The primary efficacy outcome was new stroke, and the primary safety outcome was severe or moderate bleeding, both within 90 days. Cox proportional hazards models were used to assess the interaction of TOAST classification with the effects of dual antiplatelet therapy with ticagrelor-aspirin versus clopidogrel-aspirin.

RESULTS

A total of 6336 patients were included in this study. In patients administered ticagrelor-aspirin and clopidogrel-aspirin, respectively, stroke recurred in 85 (9.8%) and 88 (10.7%) patients with large-artery atherosclerosis (hazard ratio, 0.86 [95% CI, 0.63-1.18]; P=0.34); 32 (3.6%) and 61 (7.0%) patients with small-vessel occlusion (hazard ratio, 0.51 [95% CI, 0.33-0.79]; P=0.002); and 68 (4.8%) and 87 (5.9%) patients with stroke of undetermined cause (hazard ratio, 0.80 [95% CI, 0.58-1.10]; P=0.17), with P=0.08 for the treatment×cause subtype interaction effect. There were no significant differences in severe or moderate bleeding events in patients with different cause and different treatment.

CONCLUSIONS

In this prespecified analysis of the CHANCE-2 trial, the efficacy and safety of ticagrelor-aspirin versus clopidogrel-aspirin in preventing new stroke were consistent in patients with different causes. The influence of stroke cause on benefit of gene-guided antiplatelet therapy should be explored by further trials.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04078737.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Unruptured Intracranial Aneurysm Treated with Stent-Assisted Coil Embolization: A Single-Center Cohort Study

BACKGROUND

Dual antiplatelet therapy (DAPT) of aspirin plus clopidogrel is commonly used in patients with unruptured intracranial aneurysms treated with stent-assisted coil (SAC) embolization. However, the unpredictable clopidogrel efficacy of the 5%-55% nonresponders limits its use. Ticagrelor, as a potential alternative of clopidogrel, is an antiplatelet agent with low resistance rates but uncertain efficacy and safety in these patients.

METHODS

A single-center cohort study was performed to compare the efficacy and safety of ticagrelor with clopidogrel in the DAPT regimen in patients with unruptured intracranial aneurysms and treated with SAC. The patients with clopidogrel resistance identified as inadequate adenosine diphosphate inhibition rate determined by thromboelastography were treated with ticagrelor instead, and both drugs achieved adequate suppression of platelet aggregation when stents were implanted. The occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) and bleeding events was recorded through 6 months follow-up.

RESULTS

Data from 86 patients with 99 unruptured intracranial aneurysms and treated by SAC with clopidogrel were compared with those from 108 patients with 111 aneurysms and treated with ticagrelor. Neither the baseline characteristics nor the incidence of the MACCE or bleeding events differed between the groups. Ticagrelor exerted significantly higher adenosine diphosphate inhibition rate than that of the clopidogrel. Multivariable logistic regression analysis showed that the incidence of MACCE was related to hematocrit and fibrinogen levels.

CONCLUSIONS

Ticagrelor seemed to be as effective and safe as clopidogrel for SAC in unruptured intracranial aneurysms. Hematocrit and fibrinogen levels were independent risk factors for the incidence of MACCE.

Redefining the Roles of Aspirin across the Spectrum of Cardiovascular Disease Prevention

Even before its role in platelet inhibition was fully characterized in the 1980s, aspirin had been incorporated into the cardiovascular disease care algorithm. Early trials examining its use in unstable angina and acute myocardial infarction revealed evidence of its protective role in the secondary prevention of atherosclerotic cardiovascular disease (ASCVD). Large trials assessing use in the primary prevention setting and optimal dosing regimens were studied in the late 1990s and early 2000s. As a cornerstone of cardiovascular care, aspirin was incorporated into primary and secondary ASCVD prevention guidelines in the United States and mechanical heart valve guidelines. However, in recent years, with significant advances in medical and interventional ASCVD therapies, scrutiny has been placed on the bleeding profile of aspirin, and guidelines have adapted to new evidence. Updates in primary prevention guidelines reserve aspirin only for patients at higher ASCVD risk and low bleeding risk - though questions remain in ASCVD risk assessment as risk-enhancing factors have proven difficult to incorporate on a population level. New thoughts regarding aspirin use in secondary prevention - especially with the concomitant use of anticoagulants - have altered recommendations as additional data accrued. Finally, a recommendation for aspirin and vitamin K antagonists with mechanical heart valves has been modified. Despite aspirin losing a foothold in cardiovascular care, new evidence has strengthened claims for its use in women at high risk for preeclampsia.

A randomized pilot study of the efficacy and safety of loading ticagrelor in acute ischemic stroke

BACKGROUND

Ticagrelor is one of the most recent antiplatelet drugs to be approved to treat ischemic heart disease. Its efficacy may exceed aspirin in improving clinical outcomes in patients with acute ischemic stroke who are ineligible for rt-PA.

OBJECTIVES

We evaluated the safety regarding hemorrhagic complications (as a primary endpoint) and the efficacy (as a secondary endpoint) of a 180-mg loading dose of ticagrelor given within 9 h from the onset of the first-ever non-cardioembolic ischemic stroke.

METHODS

We conducted our study on patients aged 18-75 years who presented with their first clinically manifested non-cardioembolic ischemic stroke and were recruited from the emergency department OF Kafr El-Sheik University Hospitals, Egypt. Eligible patients randomly received ticagrelor or aspirin loading and maintenance doses. Screening, randomization, and initiation of treatment all occurred within the first 9 h of stroke onset.

RESULTS

Eighty-five patients received ticagrelor, and 84 received aspirin. Patients who received ticagrelor had a better clinical outcome in terms of NIHSS improvement at 2 days and 1 week of discharge and a favorable mRS score after 1 week of discharge and at 90-day follow-up. There was no significant difference between the two groups regarding hemorrhagic adverse effects.

CONCLUSION

This pilot study found that ticagrelor had a better clinical outcome than aspirin based on NIHSS and mRS in acute ischemic stroke patients who received it within 9 h from symptom onset and had a shorter hospital stay duration. Ticagrelor was non-inferior to aspirin regarding hemorrhagic complications.

TRIAL REGISTRATION

We registered our trial on ClinicalTrials.gov, named after "ticagrelor versus aspirin in ischemic stroke," and with a clinical trial number (NCT03884530)-March 21, 2019.

Genotype-Guided Dual Antiplatelet Use for Transient Ischemic Attack and Minor Stroke by Imaging Status: Subgroup Analysis of the CHANCE-2 Trial

OBJECTIVE

This study was performed to investigate whether ticagrelor/aspirin versus clopidogrel/aspirin can further reduce the residual risk of stroke recurrence in patients with positive diffusion-weighted imaging (DWI) in the High-Risk Patients with Acute Nondisabling Cerebrovascular Events II (CHANCE-2) trial.

METHODS

Patients with DWI data in the CHANCE-2 trial were included and divided into those with and without acute infarction according to their DWI findings. The primary efficacy outcome and safety outcome were stroke recurrence and moderate to severe bleeding within 3 months of follow-up, respectively.

RESULTS

Of the 6,412 patients enrolled in the CHANCE-2 trial, 5,796 (90.4%) patients with DWI data were included in the subgroup analysis. A total of 4,369 patients (75.4%) had an acute infarction on DWI. Patients with positive DWI had higher risk of recurrent stroke (8.1%) than those without infarction (2.2%) within 3-month follow-up. Compared with clopidogrel/aspirin, ticagrelor/aspirin was associated with lower risk of stroke in patients with positive DWI (hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.52-0.80, p < 0.001) than in those negative DWI (HR = 1.22, 95% CI = 0.55-2.72, p = 0.63), with a significant interaction association (p for interaction = 0.049). The risk of moderate to severe bleeding was similar between ticagrelor/aspirin and clopidogrel/aspirin treatment in the different groups.

INTERPRETATION

Our study demonstrates that imaging evaluation should be emphasized before targeting the best candidates for genotype-guided dual antiplatelet therapy in future clinical research and practice. ANN NEUROL 2023.

Effect of CYP2C19 genetic polymorphism on the pharmacodynamics and clinical outcomes for patients treated with ticagrelor: a systematic review with qualitative and quantitative meta-analysis

BACKGROUND

Studies show inconsistent results regarding the impact of CYP2C19 genotype on the pharmacodynamics (PD) and clinical outcomes of ticagrelor. With the implementation of genotype-guided individualized antiplatelet therapy, the association between CYP2C19 polymorphism and the efficacy and safety of ticagrelor for patients is still worthy of exploring and studying.

METHODS

This systematic review protocol has been registered in the PROSPERO network (No. CRD 42020158920). Electronic databases of PubMed, EmBase, and the Cochrane Library were systematically searched from inception to January 6th, 2022 to select studies investigating the impact of CYP2C19 genotype on PD and clinical outcomes of ticagrelor. The results were presented as odds ratio (OR) or weight mean difference with its 95% confidence interval (CI) by using the random-effects model. Trial sequential analysis (TSA) was used to control risk of random errors and detect the robustness of outcomes.

RESULTS

Eight studies recruited a total of 6405 patients treated with ticagrelor. Mostly trials reported no significant effect of any or no CYP2C19 loss-of-function (LOF) allele (*2 or *3) on all the endpoints. Compared with no LOF allele carriers, subgroup analysis suggested any LOF allele in Asian patients was associated with a significant decreased risk of bleeding events (OR: 0.41; 95% CI: 0.22-0.75; P = 0.004). Furthermore, any LOF allele carriers didn't yield any impact on the risk of MACEs (OR: 1.11; 95% CI: 0.76-1.64; P = 0.586), stroke (OR: 1.71; 95% CI: 0.99-2.96; P = 0.054), definite stent thrombosis (OR: 0.88; 95% CI: 0.17-4.60; P = 0.882), bleeding (OR: 0.63; 95% CI: 0.27-1.46; P = 0.281), myocardial infarction (OR: 0.81; 95% CI: 0.30-2.20; P = 0.682), and revascularization (OR: 0.81; 95% CI: 0.33-2.00; P = 0.649) in all patients. The results of TSA were indicated that more further trials would be required.

CONCLUSIONS

This qualitative and quantitative study suggested Asian patients carrying any CYP2C19 LOF allele might have a lower risk of bleeding events comparing with no LOF allele carriers when treated with ticagrelor. However, we did not prove an important role of CYP2C19 genotype on the risk of PD and clinical endpoints in the whole cohort. In future, more large-scale prospective studies and more different ethnic populations should be included.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Intracranial Stenting or Flow-Diverter Treatment for Unruptured Cerebral Aneurysms: A Single-Center Cohort Study

BACKGROUND AND PURPOSE

Ticagrelor is a novel P2Y12 antagonist, and little is known about its efficacy and safety in the endovascular treatment of aneurysms. This study evaluated the efficacy and safety of ticagrelor versus clopidogrel for stent-assisted coiling or flow-diversion treatment in patients with unruptured cerebral aneurysms.

MATERIALS AND METHODS

From November 2003 to February 2019, two hundred one patients (mean age, 57.5 years; 156 women) with 233 unruptured aneurysms underwent stent-assisted coiling or flow-diversion treatment. All patients received antiplatelet therapy of aspirin plus clopidogrel (clopidogrel group, 121 patients with 140 aneurysms) or aspirin plus ticagrelor (ticagrelor group, 80 patients with 93 aneurysms). The clinical and radiologic data in each group were retrospectively reviewed and compared.

RESULTS

Two hundred thirty-six procedures were performed, including stent-assisted coiling (n = 101) and flow diversion (n = 135). At 90 days, the primary outcome-a composite of any stroke and death-occurred in 9.9% of the clopidogrel group and 8.6% of the ticagrelor group (P = .822). Ischemic stroke occurred in 10 (7.0%) of the clopidogrel group and 7 (7.5%) of the ticagrelor group (P > .999). Disabling stroke occurred in 4 (2.8%) in the clopidogrel group and in 4 (4.3%) in the ticagrelor group (P = .716). Ninety-day death occurred in 3 (2.1%) in the clopidogrel group and 1 (1.1%) in the ticagrelor group (P > .999). Any bleeding at 90 days occurred in 13 (9.2%) in the clopidogrel group and 6 (6.5%) in the ticagrelor group (P = .479).

CONCLUSIONS

Ticagrelor appears to be as effective and safe as clopidogrel in stent-assisted coiling or flow-diversion treatment for unruptured cerebral aneurysms.

A pilot study of the ticagrelor role in ischemic stroke secondary prevention

INTRODUCTION

Ticagrelor is one of the most recent antiplatelet drugs used to treat ischemic heart disease. Its efficacy may equal or exceed aspirin in improving clinical outcomes in patients with acute ischemic stroke who are ineligible for rt-PA.

AIM OF THE WORK

We aimed at evaluating the safety (as a primary endpoint) and efficacy (as a secondary endpoint) of a 180 mg loading dose of ticagrelor given within 9 h from the onset of first-ever ischemic stroke.

METHODS

We conducted an open-label, randomized prospective controlled clinical trial between May 2019 and September 2020 on patients who presented with their first-ever ischemic stroke and were recruited from the emergency department, of Kafr el-sheik University Hospitals, Egypt. Eligible patients randomly received aspirin or ticagrelor loading and maintenance doses. Treatment began within 9 h of stroke onset.

RESULTS

Aspirin was given to 84 patients; ticagrelor was given to 85. There was no significant difference between the 2 groups regarding the hemorrhagic and nonhemorrhagic complications. Patients who received ticagrelor had a better outcome regarding NIHSS improvement at 2 days and 1 week or discharge and a favorable mRS score after 1 week or discharge and at 90-day follow-up.

CONCLUSION

Ticagrelor was noninferior to aspirin regarding safety profile. Compared with aspirin, ticagrelor had a better clinical outcome based on NIHSS and mRS in first-ever acute ischemic stroke patients who received it within 9 h from symptom onset, leading to a shorter hospital stay.

Clopidogrel with aspirin in High-risk patients with Acute Non-disabling Cerebrovascular Events II (CHANCE-2): rationale and design of a multicentre randomised trial

Background

In patients with a minor ischaemic stroke or transient ischaemic attack (TIA), separate trials have shown that dual antiplatelet therapy with clopidogrel plus aspirin (clopidogrel–aspirin) or ticagrelor plus aspirin (ticagrelor–aspirin) are more effective than aspirin alone in stroke secondary prevention. However, these two sets of combination have not been directly compared. Since clopidogrel was less effective in stroke patients who were CYP2C19 loss-of-function (LOF) allele carriers, whether ticagrelor–aspirin is clinically superior to clopidogrel–aspirin in this subgroup of patients with stroke is unclear.

Aim

To describe the rationale and design considerations of the Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events (CHANCE-2) trial.

Design

CHANCE-2 is a randomised, double-blind, double-dummy, placebo-controlled, multicentre trial that compares two dual antiplatelet strategies for minor stroke or TIA patients who are CYP2C19 LOF allele carriers: ticagrelor (180 mg loading dose on day 1 followed by 90 mg twice daily on days 2–90) or clopidogrel (300 mg loading dose on day 1 followed by 75 mg daily on days 2–90), plus open-label aspirin with a dose of 75–300 mg on day 1 followed by 75 mg daily on day 2–21. All will be followed for 1 year.

Study outcomes

The primary efficacy outcome is any stroke (ischaemic or haemorrhagic) within 3 months and the primary safety outcome is any severe or moderate bleeding event within 3 months.

Discussion

The CHANCE-2 trial will evaluate whether ticagrelor–aspirin is superior to clopidogrel–aspirin for minor stroke or TIA patients who are CYP2C19 LOF allele carriers.

Trial registration number

NCT04078737.

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.

Antiplatelet effect of ticagrelor with aspirin in acute minor stroke and transient ischemic attack stratified by CYP2C19 metabolizer status: subgroup analysis of the PRINCE trial

Studies on antiplatelet effect of ticagrelor/aspirin and clopidogrel/aspirin in patients with acute minor stroke and transient ischemic attack (TIA) stratified by CYP2C19 metabolizer status is limited. We gained data from the Platelet Reactivity In Non-disabling Cerebrovascular Events study. Platelet reactivity was tested at baseline, 2 hours, 24 hours, 7 days and 90 days after initial dose, including high on-treatment platelet reactivity (HOPR), which was defined as P2Y12 reaction unit >208, and percentage inhibition of platelet aggregation (IPA). A total of 365 patients were included. There were 199 (54.5%) individuals classified as carriers of CYP2C19 loss-of-function alleles. For carriers and non-carriers, the proportions of HOPR were significantly lower in those with ticagrelor/aspirin compared with those with clopidogrel/aspirin at 2 hours, 24 hours, 7 days, respectively (all p<0.05). IPA was higher at all time points except at baseline in patients with ticagrelor/aspirin compared with those with clopidogrel/aspirin in both carriers and non-carriers of CYP2C19 lose-of-function alleles (all p<0.05). Our findings showed that ticagrelor/aspirin therapy possessed greater platelet inhibition and more rapid onset in platelet inhibition compared with clopidogrel/aspirin therapy both in carriers and non-carriers of CYP2C19 lose-of-function alleles with acute minor stroke or TIA.

Antithrombotic Therapy to Prevent Recurrent Strokes in Ischemic Cerebrovascular Disease: JACC Scientific Expert Panel

Stroke survivors carry a high risk of recurrence. Antithrombotic medications are paramount for secondary prevention and thus crucial to reduce the overall stroke burden. Appropriate antithrombotic agent selection should be based on the best understanding of the physiopathological mechanism that led to the initial ischemic injury. Antiplatelet therapy is preferred for lesions characterized by atherosclerosis and endothelial injury, whereas anticoagulant agents are favored for cardiogenic embolism and highly thrombophilic conditions. Large randomized controlled trials have provided new data to support recommendations for the evidence-based use of antiplatelet agents and anticoagulant agents after stroke. In this review, the authors cover recent trials that have altered clinical practice, cite systematic reviews and meta-analyses, review evidence-based recommendations based on older landmark trials, and indicate where there are still evidence-gaps and new trials being conducted.

Ticagrelor plus aspirin versus clopidogrel plus aspirin for platelet reactivity in patients with minor stroke or transient ischaemic attack: open label, blinded endpoint, randomised controlled phase II trial

OBJECTIVE

To test the hypothesis that ticagrelor plus aspirin is safe and superior to clopidogrel plus aspirin for reducing high platelet reactivity at 90 days and stroke recurrence in patients with minor stroke or transient ischaemic attack, particularly in carriers of the CYP2C19 loss-of-function allele and patients with large artery atherosclerosis.

DESIGN

Open label, blinded endpoint, randomised controlled phase II trial.

SETTING

Prospective studies conducted at 26 centres in China, August 2015 to March 2017.

PARTICIPANTS

675 patients with acute minor stroke or transient ischaemic attack.

INTERVENTION

Ticagrelor (180 mg loading dose, 90 mg twice daily thereafter) or clopidogrel (300 mg loading dose, 75 mg daily thereafter) on a background of aspirin (100 mg daily for the first 21 days) within 24 hours of symptom onset.

MAIN OUTCOME MEASURES

Primary outcome was the proportion of patients with high platelet reactivity at 90 days. High platelet reactivity was defined as P2Y12 reaction units of more than 208. Secondary outcomes included high platelet reactivity at 90 days (7 days either way) in patients carrying genetic variants that would affect clopidogrel metabolism, and any stroke (ischaemic or haemorrhagic) recurrence at 90 days (7 days either way), six months, and one year.

RESULTS

At 90 days, high platelet reactivity occurred in 35 (12.5%) of 280 patients in the ticagrelor/aspirin group and 86 (29.7%) of 290 patients in the clopidogrel/aspirin group (risk ratio 0.40; 95% confidence interval 0.28 to 0.56; P<0.001), and in 10.8% versus 35.4% (0.31; 0.18 to 0.49; P<0.001) of patients carrying CYP2C19 loss-of-function alleles. Stroke occurred in 21 (6.3%) of 336 patients in the ticagrelor/aspirin group and 30 (8.8%) of 339 patients in the clopidogrel/aspirin group (hazard ratio 0.70; 95% confidence interval 0.40 to 1.22; P=0.20). Patients with large artery atherosclerosis in the ticagrelor/aspirin group had a lower stroke recurrence at 90 days than those in the clopidogrel/aspirin group (6.0% v 13.1%; hazard ratio 0.45, 95% confidence interval 0.20 to 0.98; P=0.04). No difference was seen in the rates of major or minor haemorrhagic events between the ticagrelor/aspirin and clopidogrel/aspirin groups (4.8% v 3.5%; P=0.42).

CONCLUSION

Patients with minor stroke or transient ischaemic attack who are treated with ticagrelor plus aspirin have a lower proportion of high platelet reactivity than those who are treated with clopidogrel plus aspirin, particularly for those who are carriers of the CYP2C19 loss-of-function allele. The results of this study should be evaluated further in large scale, phase III trials and in different populations.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02506140.

Comparative Effectiveness of Aspirin and Clopidogrel Versus Aspirin in Acute Minor Stroke or Transient Ischemic Attack

Background and Purpose- This study aimed to compare the effectiveness of dual antiplatelet therapy with clopidogrel-aspirin to that of aspirin monotherapy in patients with acute minor cerebral ischemia using a prospective, nationwide, multicenter, stroke registry database in South Korea. Methods- CHANCE trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events)-like patients who met eligibility criteria modeled on the CHANCE trial eligibility criteria, including (1) acute minor ischemic stroke defined as National Institutes of Health Stroke Scale score ≤3 or lesion positive transient ischemic attack within 24 hours of onset and (2) noncardioembolic stroke mechanism. Propensity scores using the inverse probability of treatment weighting was used to adjust for baseline imbalances. The primary outcome was the composite of all stroke (ischemic and hemorrhagic), myocardial infarction, and vascular death by 3 months. Results- Among 5590 patients meeting the eligibility criteria, age was 64±13 year and 62.6% were male. Aspirin and combination of clopidogrel-aspirin were administered in 66.1% and 33.9% of patients, respectively. In unadjusted analysis, rates of the 3-month primary vascular event outcome were lower with clopidogrel-aspirin versus aspirin, 9.9% versus 12.2% (hazard ratio, 0.79 [0.67-0.95]). In propensity-weighted Cox proportional hazards regression with robust estimation, clopidogrel-aspirin was associated with a lower risk of the primary vascular event outcome (hazard ratio, 0.76 [0.63-0.92]) and all stroke events (hazard ratio, 0.74 [0.61-0.90]). Among 6 predefined subgroup analyses, 3 showed potential modification of treatment effect, with lesser benefit associated with the absence of prior antiplatelet use (Pinteraction=0.01) and younger age (<75 years, Pinteraction=0.07), and absence of benefit associated with small vessel occlusion subtype (Pinteraction=0.08). Conclusions- Dual antiplatelet therapy with aspirin and clopidogrel was associated with reduced stroke, myocardial infarction, and vascular death in the 3 months following a presenting minor, noncardioembolic ischemic stroke. Benefits may be particularly magnified in patients with a history of prior antiplatelet therapy, older age, and nonsmall vessel disease stroke mechanism.

Advances in Stroke Prevention

There have been recent advances in stroke prevention in nutrition, blood pressure control, antiplatelet therapy, anticoagulation, identification of high-risk asymptomatic carotid stenosis, and percutaneous closure of patent foramen ovale. There is evidence that the Mediterranean diet significantly reduces the risk of stroke and that B vitamins lower homocysteine, thus preventing stroke. The benefit of B vitamins to lower homocysteine was masked by harm from cyanocobalamin among study participants with impaired renal function; we should be using methylcobalamin instead of cyanocobalamin. Blood pressure control can be markedly improved by individualized therapy based on phenotyping by plasma renin and aldosterone. Loss of function mutations of CYP2D19 impair activation of clopidogrel and limits its efficacy; ticagrelor can avoid this problem. New oral anticoagulants that are not significantly more likely than aspirin to cause severe bleeding, and prolonged monitoring for atrial fibrillation (AF), have revolutionized the prevention of cardioembolic stroke. Most patients (~90%) with asymptomatic carotid stenosis are better treated with intensive medical therapy; the few that could benefit from stenting or endarterectomy can be identified by a number of approaches, the best validated of which is transcranial Doppler (TCD) embolus detection. Percutaneous closure of patent foramen ovale has been shown to be efficacious but should only be implemented in selected patients; they can be identified by clinical clues to paradoxical embolism and by TCD estimation of shunt grade. “Treating arteries instead of treating risk factors,” and recent findings related to the intestinal microbiome and atherosclerosis point the way to promising advances in future.

Significance of Nonfocal Symptoms in Patients With Transient Ischemic Attack

Background and Purpose- Patients with transient ischemic attack (TIA) occasionally show nonfocal symptoms, such as unconsciousness, amnesia, and unsteadiness. The purpose of this study was to clarify the characteristics and prognosis of patients with TIA with nonfocal symptoms, using data from the PROMISE-TIA (Prospective Multicenter Registry to Identify Subsequent Cardiovascular Events After Transient Ischemic Attack). Methods- Patients with TIA within 7 days of onset were consecutively enrolled in the Japanese nationwide registry. Factors associated with nonfocal symptoms and 1-year risks of ischemic stroke and coronary artery diseases were assessed in multivariate-adjusted models. Results- We studied 1362 patients with TIA (879 men; mean age, 69±12 years), including 219 (16%) with nonfocal symptoms. Patients with TIA with nonfocal symptoms were more likely to show acute ischemic lesions in the posterior circulation on diffusion-weighted imaging (multivariate-adjusted odds ratio, 3.07; 95% confidence interval, 1.57-5.82) and arterial stenosis or occlusion in the posterior circulation on vascular examination (odds ratio, 1.94; 95% confidence interval, 1.19-3.09) than those without nonfocal symptoms. Although 1-year risk of ischemic stroke did not differ significantly between groups (adjusted hazard ratio, 0.79; 95% confidence interval, 0.42-1.37), risk of coronary artery disease was higher in patients with TIA with nonfocal symptoms (hazard ratio, 3.37; 95% confidence interval, 1.14-9.03). Conclusions- Both acute ischemic lesions and arterial stenosis and occlusion in the posterior circulation were more frequently observed in patients with TIA with nonfocal symptoms.

Dual versus mono antiplatelet therapy for acute non-cardioembolic ischaemic stroke or transient ischaemic attack: a systematic review and meta-analysis

Objective

Recent years have seen new evidence on the efficacy and safety of dual antiplatelet therapy for secondary stroke prevention. We updated a meta-analysis of randomised controlled trials evaluating dual antiplatelet versus monotherapy for patients with acute non-cardioembolic ischaemic stroke (IS) or transient ischaemic attack (TIA).

Methods

We searched PubMed and identified randomised controlled trials evaluating dual antiplatelet versus monotherapy for acute non-cardioembolic IS or TIA within 3 days of ictus up to May 2018. Risk ratio (RR) with 95% CI were calculated using random effects models. Clinical endpoints included stroke recurrence, composite vascular events and major bleeding.

Results

18 randomised controlled trials including 15 515 patients were pooled in the meta-analysis. When compared with monotherapy among patients with acute IS or TIA, dual antiplatelet therapy reduced the risk of stroke recurrence (RR 0.69; 95% CI 0.61 to 0.78; p<0.001) and composite vascular events (RR 0.72; 95% CI 0.64 to 0.80; p<0.001). Dual therapy was associated with a significant increase in the risk of major bleeding (RR 1.77; 95% CI 1.09 to 2.87; p=0.02) when all trial data were combined. However, when all previous trials before the completion of the POINT trial were analysed, dual antiplatelet versus monotherapy was not associated with a significant increase in the risk of major bleeding (RR 1.46; 95% CI 0.77 to 2.75; p=0.25).

Conclusions

Among patients with acute non-cardioembolic IS or TIA within 3 days of ictus, dual antiplatelet therapy was associated with a reduction in stroke recurrence, and composite vascular events, when compared with monotherapy. However, a significant increase in the risk of major bleeding was observed.

Antiplatelet therapy after stroke: should it differ in the acute and chronic phase after stroke

PURPOSE OF REVIEW

Reviewing existing evidence regarding well tolerated and effective antiplatelet treatment in patients with acute or chronic, noncardioembolic ischemic stroke and transient ischemic attack (TIA).

RECENT FINDINGS

For patients with high-risk stroke or TIA, for instance, minor stroke or high-risk TIA, or stroke of atherosclerotic origin with evidence suggesting risk of artery-to-artery embolism or with high-grade, symptomatic arterial stenosis, early initiated, short-term dual antiplatelet (e.g. aspirin and clopidogrel) is effective in reducing the risk of recurrent stroke and other vascular events which does not increase the risk of severe or fatal bleeding, as compared with mono antiplatelet therapy. However, long-term application of aggressive antiplatelet therapies after a noncardioembolic stroke or TIA increases the bleeding risks. Triple antiplatelet therapy is not appropriate for noncardioembolic stroke or TIA, in view of the high bleeding risk. In addition, emerging antiplatelets such as ticagrelor and cilostazol may work better in certain subgroups of stroke patients, which warrants further investigation.

SUMMARY

Antiplatelet therapies should differ in the acute and chronic phases among patients with high-risk stroke or TIA when more aggressive antiplatelet treatment is reasonable in the acute phase, but no solid evidence supports different antiplatelet strategies in acute and chronic phases in patients with low-risk noncardioembolic stroke.

Ticagrelor - toward more efficient platelet inhibition and beyond

Novel antiplatelet drugs, including ticagrelor, are being successively introduced into the therapy of atherothrombotic conditions due to their superiority over a standard combination of clopidogrel with acetylsalicylic acid in patients with acute coronary syndromes (ACS). A P2Y12 receptor antagonist, ticagrelor, is unique among antiplatelet drugs, because ticagrelor inhibits the platelet P2Y12 receptor in a reversible manner, and because it demonstrates a wide palette of advantageous pleiotropic effects associated with the increased concentration of adenosine. The pleiotropic effects of ticagrelor comprise cardioprotection, restoration of the myocardium after an ischemic event, promotion of the release of anticoagulative factors and, eventually, anti-inflammatory effects. Beyond the advantageous effects, the increased concentration of adenosine is responsible for some of ticagrelor's adverse effects, including dyspnea and bradycardia. Large-scale clinical trials demonstrated that both standard 12-month therapy and long-term use of ticagrelor reduce the risk of cardiovascular events in patients with ACS, but at the expense of a higher risk of major bleeding. Further trials focused on the use of ticagrelor in conditions other than ACS, including ischemic stroke, peripheral artery disease and status after coronary artery bypass grafting. The results of these trials suggest comparable efficacy and safety of ticagrelor and clopidogrel in extra-coronary indications, but firm conclusions are anticipated from currently ongoing studies. Here, we summarize current evidence on the superiority of ticagrelor over other P2Y12 antagonists in ACS, discuss the mechanism underlying the drug-drug interactions and pleiotropic effects of ticagrelor, and present future perspectives of non-coronary indications for ticagrelor.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5–10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.

Medical Treatment of Intracranial Atherosclerosis: An Update

For patients with symptomatic intracranial atherosclerosis (ICAS), antithrombotic agents are the mainstay of therapy. Anticoagulation (warfarin) is not widely used since it is not more effective than aspirin and carries a high risk of bleeding. New oral anticoagulants are showing promise, but their use has not been investigated in appropriate clinical trials. Since the recurrent stroke risk is high with aspirin monotherapy, dual antiplatelets are considered in the early stage of symptomatic ICAS. Based on the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) and Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) results, aspirin plus clopidogrel has been recommended. However, this combination was not superior to aspirin monotherapy in patients with ICAS in the CHANCE substudy. Progression of ICAS is common, and it is associated with recurrent strokes. In the Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis (TOSS) study, aspirin plus cilostazol was more effective than aspirin monotherapy in preventing progression. The TOSS II trial showed that the overall change in stenosis was better with aspirin plus cilostazol than with aspirin plus clopidogrel. Aside from antithrombotic therapy, risk factor management is critical for secondary prevention, and high blood pressure is clearly linked to recurrent stroke. However, blood pressure may have to be cautiously managed in the early stage of stroke. Considering that ICAS is the major cause of stroke worldwide, further investigations are needed to establish optimal management strategies for patients with ICAS.

Recent advances in preventing stroke recurrence

Recent advances in secondary stroke prevention include new evidence in hypertension, nutrition, anticoagulation, antiplatelet therapy, intracranial stenosis, percutaneous closure of patent foramen ovale, and lipid-lowering therapy. Individualized therapy for hypertension based on phenotyping with plasma renin and aldosterone markedly improves blood pressure control in patients with resistant hypertension. A Mediterranean diet can reduce the risk of stroke by nearly half. The diagnosis and treatment of metabolic vitamin B12 deficiency, and B vitamins to lower homocysteine, can reduce the risk of stroke by approximately 30%. There are problems with clopidogrel that can be overcome by using ticagrelor, and new anticoagulant drugs markedly improve anticoagulation for stroke prevention, particularly in atrial fibrillation. There are pharmacokinetic problems with dabigatran that deserve attention. Intensive medical therapy is better than stenting for intracranial stenosis, and new therapies directed at proprotein convertase subtilisin–kexin type 9 (PCSK9) will revolutionize lipid-lowering therapy. In the past, it was estimated that rational therapy could reduce recurrent stroke by about 80%. With recent advances, we should be able to do even better.