Clopidogrel and aspirin after ischemic stroke or transient ischemic attack: an updated systematic review and meta-analysis of randomized clinical trials

Trends in Dual Antiplatelet Therapy of Aspirin and Clopidogrel and Outcomes in Ischemic Stroke Patients Noneligible for POINT/CHANCE Trial Treatment

BACKGROUND

Recent clinical trials established the benefit of dual antiplatelet therapy with aspirin and clopidogrel (DAPT-AC) in early-presenting patients with minor ischemic stroke. However, the impact of these trials over time on the use and outcomes of DAPT-AC among the patients with nonminor or late-presenting stroke who do not meet the eligibility criteria of these trials has not been delineated.

METHODS AND RESULTS

In a multicenter stroke registry, this study examined yearly changes from April 2008 to August 2022 in DAPT-AC use for stroke patients ineligible for CHANCE/POINT (Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events/Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke) clinical trials due to National Institutes of Health Stroke Scale >4 or late arrival beyond 24 hours of onset. A total of 32 118 patients (age, 68.1±13.1 years; male, 58.5%) with National Institutes of Health Stroke Scale of 4 (interquartile range, 1-7) were analyzed. In 2008, DAPT-AC was used in 33.0%, other antiplatelets in 62.7%, and no antiplatelet in 4.3%. The frequency of DAPT-AC was relatively unchanged through 2013, when the CHANCE trial was published, and then increased steadily, reaching 78% in 2022, while other antiplatelets decreased to 17.8% in 2022 (Ptrend<0.001). From 2011 to 2022, clinical outcomes nonsignificantly improved, with an average relative risk reduction of 2%/y for the composite of stroke, myocardial infarction, and all-cause mortality, both among patients treated with DAPT-AC and patients treated with other antiplatelets.

CONCLUSIONS

Use of DAPT-AC in stroke patients with stroke ineligible for recent DAPT clinical trials increased markedly and steadily after CHANCE publication in 2013, reaching deployment in nearly 4 of every 5 patients by 2022. The secondary prevention in patients with ischemic stroke seems to be gradually improving, possibly due to the enhancement of risk factor control.

Deep learning-based white matter lesion volume on CT is associated with outcome after acute ischemic stroke

BACKGROUND

Intravenous thrombolysis (IVT) before endovascular treatment (EVT) for acute ischemic stroke might induce intracerebral hemorrhages which could negatively affect patient outcomes. Measuring white matter lesions size using deep learning (DL-WML) might help safely guide IVT administration. We aimed to develop, validate, and evaluate a DL-WML volume on CT compared to the Fazekas scale (WML-Faz) as a risk factor and IVT effect modifier in patients receiving EVT directly after IVT.

METHODS

We developed a deep-learning model for WML segmentation on CT and validated with internal and external test sets. In a post hoc analysis of the MR CLEAN No-IV trial, we associated DL-WML volume and WML-Faz with symptomatic-intracerebral hemorrhage (sICH) and 90-day functional outcome according to the modified Rankin Scale (mRS). We used multiplicative interaction terms between WML measures and IVT administration to evaluate IVT treatment effect modification. Regression models were used to report unadjusted and adjusted common odds ratios (cOR/acOR).

RESULTS

In total, 516 patients from the MR CLEAN No-IV trial (male/female, 291/225; age median, 71 [IQR, 62-79]) were analyzed. Both DL-WML volume and WML-Faz are associated with sICH (DL-WML volume acOR, 1.78 [95%CI, 1.17; 2.70]; WML-Faz acOR, 1.53 95%CI [1.02; 2.31]) and mRS (DL-WML volume acOR, 0.70 [95%CI, 0.55; 0.87], WML-Faz acOR, 0.73 [95%CI 0.60; 0.88]). Only in the unadjusted IVT effect modification analysis WML-Faz was associated with more sICH if IVT was given (p = 0.046). Neither WML measure was associated with worse mRS if IVT was given.

CONCLUSION

DL-WML volume and WML-Faz had a similar relationship with functional outcome and sICH. Although more sICH might occur in patients with more severe WML-Faz receiving IVT, no worse functional outcome was observed.

CLINICAL RELEVANCE STATEMENT

White matter lesion severity on baseline CT in acute ischemic stroke patients has a similar predictive value if measured with deep learning or the Fazekas scale. Safe administration of intravenous thrombolysis using white matter lesion severity should be further studied.

KEY POINTS

White matter damage is a predisposing risk factor for intracranial hemorrhage in patients with acute ischemic stroke but remains difficult to measure on CT. White matter lesion volume on CT measured with deep learning had a similar association with symptomatic intracerebral hemorrhages and worse functional outcome as the Fazekas scale. A patient-level meta-analysis is required to study the benefit of white matter lesion severity-based selection for intravenous thrombolysis before endovascular treatment.

Antiplatelet Treatment Patterns and Outcomes for Secondary Stroke Prevention in the United Kingdom

INTRODUCTION

Stroke is a leading cause of death and disability worldwide. Antiplatelet therapies are recommended to reduce the risk of recurrent stroke in patients with ischemic stroke/transient ischemic attack (IS/TIA). This study evaluated outpatient antiplatelet treatment patterns and outcomes for secondary stroke prevention (SSP) among UK adults without atrial fibrillation who were hospitalized for IS/TIA.

METHODS

This retrospective observational study utilized data from the UK Clinical Practice Research Datalink linked with Hospital Episode Statistics data (01/01/2011-30/06/2019). Treatment patterns included type and duration of treatments. Treatment outcomes included IS, myocardial infarction, major bleeding, and cardiovascular-related and all-cause mortality. Descriptive statistics were reported.

RESULTS

Of 9270 patients, 13.9% (1292) might not receive antithrombotic therapy within 90 days of hospital discharge. Of 7978 patients who received antiplatelet therapies, most used clopidogrel (74.8%) or aspirin (16.7%) single antiplatelet therapy and clopidogrel + aspirin dual antiplatelet therapy (DAPT, 5.9%). At 1-year post-hospitalization, 36.9, 43.3, and 35.1% of those receiving these treatments discontinued them, respectively, and of the patients initiating DAPT, 62.3% switched to single antiplatelet therapy. At 1-year post-discharge, the incidence rate (per 100 person-years) of IS, myocardial infarction, major bleeding, cardiovascular-related mortality, and all-cause mortality among the treated were 6.5, 0.7, 4.1, 5.0, and 7.3, respectively, and among the untreated were 14.9, 0.7, 8.6, 28.1, and 39.8, respectively.

CONCLUSIONS

In the United Kingdom, 13.9% of patients hospitalized for stroke might not have any antiplatelet treatment to prevent secondary stroke; among the treated, clopidogrel, aspirin, and DAPT were commonly used. These study findings suggest that improved anti-thrombotic therapies for long-term SSP treatment are needed, which may lead to higher treatment and persistence rates and, therefore, improved outcomes in this population.

Human Serum Albumin-enriched Clopidogrel Bisulfate Nanoparticle Alleviates Cerebral Ischemia-Reperfusion Injury in Rats

PURPOSE

Cerebral ischemia-reperfusion (I/R) injury remains a leading cause of mobility and mortality among patients with ischemic stroke. This study aims to develop a human serum albumin (HSA)-enriched nanoparticle platform for solubilizing clopidogrel bisulfate (CLP) for intravenous administration, and to explore the protective effect of HSA-enriched nanoparticles loaded with CLP (CLP-ANPs) against cerebral I/R injury in transient middle cerebral artery occlusion (MCAO) rat model.

METHODS

CLP-ANPs were synthesized via a modified nanoparticle albumin-bound technology, lyophilized, and then characterized by morphology, particle size, zeta potential, drug loading capacity, encapsulation efficiency, stability and in vitro release kinetics. In vivo pharmacokinetic studies were conducted using Sprague-Dawley (SD) rats. Also, an MCAO rat model was established to explore the therapeutic effect of CLP-ANPs on cerebral I/R injury.

RESULTS

CLP-ANPs remained spherical particles with a layer of proteins forming protein corona. Lyophilized CLP-ANPs after dispersion displayed an average size of about 235.6 ± 6.6 nm (PDI = 0.16 ± 0.08) with a zeta potential of about - 13.5 ± 1.8 mV. CLP-ANPs achieved sustained release for up to 168 h in vitro. Next, a single injection of CLP-ANPs dose-dependently reversed the histopathological changes induced by cerebral I/R injury possibly via attenuating apoptosis and reducing oxidative damages in the brain tissues.

CONCLUSIONS

CLP-ANPs represent a promising and translatable platform system for the management of cerebral I/R injury during ischemic stroke.

Risk factors for gastrointestinal bleeding in patients with cerebral infarction after dual antiplatelet therapy

BACKGROUND

To investigate the risk factors for gastrointestinal bleeding in patients with cerebral infarction after dual antiplatelet therapy.

METHODS

Cerebral infarction patients who received dual antiplatelet therapy during January 2019 and December 2021 in Nanchang University Affiliated Ganzhou Hospital were included. Patients were divided into a bleeding group and a nonbleeding group. Propensity score matching was used to match the data between the two groups. The risk factors for cerebral infarction with gastrointestinal bleeding after receiving dual antiplatelet therapy were analyzed by conditional logistic regression.

RESULTS

There were 2370 cerebral infarction patients who received dual antiplatelet therapy included in the study. There were significant differences between the bleeding group and the nonbleeding group in terms of sex, age, smoking, drinking, hypertension, coronary heart disease, diabetes and peptic ulcer before matching. After matching, 85 patients were included in the bleeding group and nonbleeding group, and there was no significant difference between the two groups in terms of sex, age, smoking, drinking, previous cerebral infarction, hypertension, coronary heart disease, diabetes, gout or peptic ulcer. Conditional logistic regression analysis showed that long-term use of aspirin and severity of cerebral infarction were risk factors for gastrointestinal bleeding in cerebral infarction patients receiving dual antiplatelet therapy, whereas the use of PPI was a protective factor against gastrointestinal bleeding.

CONCLUSIONS

Long-term use of aspirin and severity of cerebral infarction are risk factors for gastrointestinal bleeding in cerebral infarction patients receiving dual antiplatelet therapy. The use of PPIs could reduce the risk of gastrointestinal bleeding.

P2Y12 inhibitors plus aspirin for acute treatment and secondary prevention in minor stroke and high-risk transient ischemic attack: A systematic review and meta-analysis

BACKGROUND

Aspirin is a cornerstone of preventive treatment for stroke recurrence, but during the last few years the role of dual antiplatelet therapy (DAPT) is much more emerging.

OBJECTIVE

This systematic review aimed to compare early use of P2Y12 inhibitors (clopidogrel/ticagrelor) plus aspirin to aspirin alone for acute treatment and secondary prevention in acute non-cardioembolic minor ischemic stroke or TIA.

METHODS

A systematic search on MEDLINE and EMBASE was performed. Treatment effects were estimated with RRs and 95% CI. We used RevMan 5.4 for data analyses. We assessed methodological quality of selected studies according to Rob2 tools and quality of evidence with GRADE approach.

RESULTS

Four RCTs were included, enrolling 21,459 patients. Compared to aspirin alone, DAPT was superior in reducing stroke recurrence (RR 0.74, 95% CI 0.67-0.82, P <0.00001, absolute risk difference by 2%, NNT 50) and disabling stroke defined as mRS>2 (RR 0.84, 95% CI 0.75-0.95, P = 0.004), with no impact on all causes of mortality (RR 1.30, 95% CI 0.90-1.89, P = 0.16). An increased risk of major bleeding was emerged (RR 2.54, 95% CI 1.65-3.92, P <0.0001, absolute risk difference by 0,4%, NNH 250), in particular with ticagrelor, but there was no correlation between therapy duration and bleeding risk, as appeared from one-month (RR 3.06, 95% CI 1.64 to 5.69) and three-month (RR 2.09, 95% CI 1.18 to 3.69) follow-up analysis.

CONCLUSIONS

Early administration of P2Y12 inhibitors plus aspirin in patients with acute non-cardioembolic minor ischemic stroke or TIA reduced the incidence of ischemic stroke recurrence, impacting more significantly than the increased bleeding risk and influencing patients' quality of life by reducing disabling stroke.

Contemporary antiplatelet therapy for secondary stroke prevention: a narrative review of current literature and guidelines

Antiplatelet therapy is one of the mainstays for secondary stroke prevention. This narrative review aimed to highlight the current evidence and recommendations of antiplatelet therapy for stroke prevention.We conducted advanced literature search for antiplatelet therapy. Landmark studies and randomised controlled trials evaluating antiplatelet therapy for secondary stroke prevention are reviewed. Results from Cochrane systematic review, pooled data analysis and meta-analysis are discussed.Single-antiplatelet therapy (SAPT) with aspirin, aspirin/extended-release dipyridamole or clopidogrel reduces the risk of recurrent ischaemic stroke in patients with non-cardioembolic ischaemic stroke or transient ischaemic attack (TIA). Dual-antiplatelet therapy (DAPT) with aspirin and clopidogrel or ticagrelor for 21-30 days is more effective than SAPT in patients with minor acute noncardioembolic ischaemic stroke or high-risk TIA. Prolonged use of DAPT is associated with higher risk of haemorrhage without reduction in stroke recurrence than SAPT. Compared with placebo, aspirin reduces the relative risk of recurrent stroke by approximately 22%. Aspirin/dipyridamole and cilostazol are superior to aspirin but associated with significant side effects. Cilostazol or ticagrelor might be more effective than aspirin or clopidogrel in patients with intracranial stenosis.SAPT is indicated for secondary stroke prevention in patients with non-cardioembolic ischaemic stroke or TIA. DAPT with aspirin and clopidogrel or ticagrelor for 21-30 days followed by SAPT is recommended for patients with minor acute noncardioembolic stroke or high-risk TIA. Selection of appropriate antiplatelet therapy should also be based on compliance, drug tolerance or resistance.

The Efficacy and Safety of Cilostazol vs. Aspirin for Secondary Stroke Prevention: A Systematic Review and Meta-Analysis

Background

Cilostazol is often used in Asia-Pacific countries for stroke prevention. The current systematic review and meta-analysis aimed to evaluate the effectiveness, safety, and adverse outcomes of cilostazol monotherapy compared to aspirin monotherapy for secondary stroke prevention.

Methods

The researchers conducted a comprehensive research in multiple databases (PubMed, Embase, and Cochrane library) of randomized controlled trials from conception to December 2020. The primary efficacy outcome was the occurrence of any stroke, the primary safety outcome was the bleeding risk, and the primary adverse outcome was the rate of headache and dizziness. The Mantel-Haenszel method was used to calculate a random-effects prediction. Cilostazol and aspirin were compared using a pooled risk assessment with 95% CIs.

Results

Six studies involving 5,617 patients were included in this review. Compared with aspirin monotherapy, cilostazol was associated with significantly lower rates of any strokes (RR: 0.67; 95% CI: 0.55–0.82) and significantly lower bleeding rates [risk ratio (RR): 0.53; 95% CI: 0.37–0.74]. However, compared with aspirin monotherapy, cilostazol was associated with significantly higher rates of headache (RR: 1.77; 95% CI: 1.41–2.20) and dizziness (RR: 1.28; 95% CI: 1.08–1.52).

Conclusions

Consistent with previous studies, cilostazol monotherapy is superior to aspirin monotherapy in reducing the rate of any strokes and the bleeding risk after having a stroke. However, the use of cilostazol monotherapy is associated with several adverse life outcomes such as headaches and dizziness.

Efficacy and safety of clopidogrel and/or aspirin for ischemic stroke/transient ischemic attack: An overview of systematic reviews and meta-analysis

OBJECTIVE

Patients experiencing acute ischemic stroke or transient ischemic attack are commonly treated with clopidogrel and/or aspirin (mono- and dual-antiplatelet therapy) to minimize the risk for recurrent stroke. Updated data from systematic studies can be used to guide practice. The present study aimed to compare findings from systematic reviews and meta-analyses addressing the efficacy and safety of clopidogrel or aspirin - alone or in combination - in patients experiencing acute ischemic stroke or transient ischemic attack.

METHODS

The Cochrane Library, PubMed, Ovid, Scopus, EBSCO, and CINAHL databases were searched for relevant studies published from inception to 2020. Data from each study were extracted independently using a predefined data abstraction form. The Risk of Bias in Systematic Reviews tool and A Measurement Tool to Assess Systematic Reviews 2 were used to evaluate risk of bias and the quality of the included studies.

RESULTS

Seven studies, published between 2010 and 2020, were eligible for analysis. The included studies evaluated a wide range of outcomes, including recurrent stroke, myocardial infarction, recurrent ischemic stroke, vascular mortality and vascular events, bleeding events, all-cause mortality, functional disability, and quality of life. The risk of bias and methodological validity of the included studies ranged from low to high according to ROBIS and AMSTAR 2 parameters. Results revealed that clopidogrel plus aspirin was more effective than aspirin alone in reducing the risk for recurrent stroke (ischemic or hemorrhagic), with high-quality evidence. However, compared with aspirin, dual treatment increased major bleeding events (intracranial bleeding and extracranial bleeding), supported by high-quality evidence.

CONCLUSIONS

High-quality evidence suggested that clopidogrel plus aspirin was more efficient than monotherapy, although the risk for hemorrhagic stroke was relatively higher in combined therapy regimens lasting >1 month.

Analysis of CYP2C19 genetic variants with ischaemic events in UK patients prescribed clopidogrel in primary care: a retrospective cohort study

OBJECTIVE

To determine whether CYP2C19 loss-of-function (LoF) alleles increase risk of ischaemic stroke and myocardial infarction (MI) in UK primary care patients prescribed clopidogrel.

DESIGN

Retrospective cohort analysis.

SETTING

Primary care practices in the UK from January 1999 to September 2017.

PARTICIPANTS

7483 European-ancestry adults from the UK Biobank study with genetic and linked primary care data, aged 36-79 years at time of first clopidogrel prescription.

INTERVENTIONS

Clopidogrel prescription in primary care, mean duration 2.6 years (range 2 months to 18 years).

MAIN OUTCOME MEASURE

Hospital inpatient-diagnosed ischaemic stroke, MI or angina while treated with clopidogrel.

RESULTS

28.7% of participants carried at least one CYP2C19 LoF variant. LoF carriers had higher rates of incident ischaemic stroke while treated with clopidogrel compared with those without the variants (8 per 1000 person-years vs 5.2 per 1000 person-years; HR 1.53, 95% CIs 1.04 to 2.26, p=0.031). LoF carriers also had increased risk of MI (HR 1.14, 95% CI 1.04 to 1.26, p=0.008). In combined analysis LoF carriers had increased risk of any ischaemic event (stroke or MI) (HR 1.17, 95% CI 1.06 to 1.29, p=0.002). Adjustment for aspirin coprescription produced similar estimates. In lifetables using observed incidence rates, 22.5% (95% CI 14.4% to 34.0%) of CYP2C19 LoF carriers on clopidogrel were projected to develop an ischaemic stroke by age 79 (oldest age in the study), compared with 15.4% (95% CI 11.4% to 20.5%) in non-carriers, that is, 7.1% excess stroke incidence in LoF carriers by age 79.

CONCLUSIONS

A substantial proportion of the UK population carry genetic variants that reduce metabolism of clopidogrel to its active form. In family practice patients on clopidogrel, CYP2C19 LoF variants are associated with substantially higher incidence of ischaemic events. Genotype-guided selection of antiplatelet medications may improve outcomes in patients carrying CYP2C19 genetic variants.

Aquaporins in platelet function

Structurally, aquaporins (AQPs) are small channel proteins with monomers of ~ 30 kDa that are assembled as tetramers to form pores on cell membranes. Aquaporins mediate the conduction of water but at times also small solutes including glycerol across cell membranes and along osmotic gradients. Thirteen isoforms of AQPs have been reported in mammalian cells, and several of these are likely expressed in platelets. Osmotic swelling mediated by AQP1 sustains the calcium entry required for platelet phosphatidylserine exposure and microvesiculation, through calcium permeable stretch-activated or mechanosensitive cation channels. Notably, deletion of AQP1 diminishes platelet procoagulant membrane dynamics in vitro and arterial thrombosis in vivo, independent of platelet granule secretion and without affecting hemostasis. Water entry into platelets promotes procoagulant activity, and AQPs may also be critical for the initiation and progression of venous thrombosis. Platelet AQPs may therefore represent valuable targets for future development of a new class of antithrombotics, namely, anti-procoagulant antithrombotics, that are mechanistically distinct from current antithrombotics. However, the structure of AQPs does not make for easy targeting of these channels, hence they remain elusive drug targets. Nevertheless, thrombosis data in animal models provide compelling reasons to continue the pursuit of AQP-targeted antithrombotics. In this review, we discuss the role of aquaporins in platelet secretion, aggregation and procoagulation, the challenge of drugging AQPs, and the prospects of targeting AQPs for arterial and venous antithrombosis.

Benefits and Risks of Dual Versus Single Antiplatelet Therapy for Secondary Stroke Prevention: A Systematic Review for the 2021 Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack

BACKGROUND

Dual antiplatelet therapy (DAPT) after ischemic stroke or transient ischemic attack may reduce recurrent stroke but also increase severe bleeding compared with single antiplatelet therapy (SAPT). The American Heart Association/American Stroke Association convened an evidence review committee to perform a systematic review and meta-analysis of the benefits and risks of DAPT compared with SAPT for secondary ischemic stroke prevention.

METHODS

The Medline, Embase, and Cochrane databases were searched on December 5, 2019, to identify phase III or IV randomized controlled trials (n≥100) from December 1999 to December 2019. We calculated unadjusted relative risks (RRs) and performed meta-analyses of studies based on the duration of treatment (short [≤90 days] versus long [>90 days]).

RESULTS

Three short-duration randomized controlled trials were identified that enrolled mostly patients with minor stroke or high risk transient ischemic attack. In these trials, DAPT, compared with SAPT, was associated with a lower 90-day risk of recurrent ischemic stroke (pooled RR, 0.68 [95% CI, 0.55-0.83], I ²=37.1%). There was no significant increase in major bleeding with DAPT in short-duration trials (pooled RR, 1.88 [95% CI, 0.93-3.83], I ²=8.9%). In 2 long-duration treatment randomized controlled trials (mean treatment duration, 18-40 months), DAPT was not associated with a significant reduction in recurrent ischemic stroke (pooled RR, 0.89 [95% CI, 0.79-1.02], I ²=1.4%), but was associated with a higher risk of major bleeding (pooled RR, 2.42 [95% CI, 1.37-4.30], I ²=75.5%).

CONCLUSIONS

DAPT was more effective than SAPT for prevention of secondary ischemic stroke when initiated early after the onset of minor stroke/high-risk transient ischemic attack and treatment duration was <90 days. However, when the treatment duration was longer and initiated later after stroke or transient ischemic attack onset, DAPT was not more effective than SAPT for ischemic stroke prevention and it increased the risk of bleeding.

Polymorphisms of genes related to phase-I metabolic enzymes affecting the clinical efficacy and safety of clopidogrel treatment

Introduction: Clopidogrel is an antiplatelet medication described as a prodrug, which cannot exert the antiplatelet effect until being biotransformed to the active metabolite. It is commonly used to reduce the risk of blood coagulation in patients diagnosed with acute coronary syndrome, or ischemic stroke.Area covered: We reviewed published articles in PubMed and Google Scholar that focused on the mutations of CYP2C19, CYP3A4, CYP2C9, CYP2B6, and CYP1A2 genes related to clopidogrel clinical efficacy and safety.Expert opinion: Based on current pharmacogenetic studies, patients carrying CYP2C19*2, CYP2C19*3, CYP2C9*3, and CYP2B6*5 alleles may not respond to clopidogrel due to poor platelet inhibition efficacy revealed among them. In contrast, carriers of CYP2C19*17, CYP3A4*1G, and CYP1A2*1C alleles showed a more significant antiplatelet effect in clopidogrel users and expected to have a protective role as a genetic factor against cardiovascular events. Genotyping for either CYP2C19, CYP3A4, CYP2C9, CYP2B6, or CYP1A2 variants is not recommended when considering clopidogrel treatment for patients, as some trials showed specific non-genetic factors (e.g. age and diabetes) that could affect clopidogrel responsiveness. Instead, platelets inhibition tests could be used as predictors of the clinical efficacy of clopidogrel treatment. Other P2Y12 receptor inhibitors should be considered as alternative medications.

The 2020 breakthroughs in early secondary prevention: dual antiplatelet therapy versus single antiplatelet therapy

PURPOSE OF REVIEW

Single antiplatelet therapy represents an established treatment in secondary prevention of ischemic strokes and transient ischemic attacks (TIAs). In contrast with coronary artery disease, the use of dual antiplatelet therapy (DAPT) for secondary prevention in patients with acute cerebral ischemia (ACI) remains under debate. In this narrative review, we present and analyse the most recent findings concerning the potential efficacy and safety of DAPT therapy after ischemic strokes or TIA.

RECENT FINDINGS

Following the publication of the three (CHANCE, POINT and THALES) large, randomized-controlled, clinical trials (RCTs) that showed efficacy of early DAPT for the secondary prevention after minor AIS or TIA, short-term DAPT use is becoming the most prevalent choice of treatment. Notably, DAPT is even more popular after AIS attributed to large artery atherosclerosis given randomized data from small RCTs supporting the use of DAPT in patients with extracranial or intracranial atherosclerosis and microembolization detected by transcranial Doppler. Recent subanalysis of data from the randomized trials aim to identify specific patient subgroups, which are determined by genetic, imaging or clinical characteristics, and for whom DAPT appears to be more beneficial. The potential role of different antiplatelet agents (aspirin, clopidogrel, ticagrelor) is also discussed.

SUMMARY

DAPT has recently proven its efficacy for the early secondary prevention of AIS patients with minor stroke severity and high-risk TIA patients. However, the length of DAPT is still controversial, as well as the individualized selection of AIS or TIA patients with the lower risk of bleeding and with the greater benefit in prevention of ischemic cerebrovascular and cardiovascular events.

Continuation of aspirin perioperatively for lung resection: a propensity matched analysis

PURPOSE

To clarify the safety and effectiveness of continuing aspirin during the perioperative period of lung resection.

METHODS

We analyzed, retrospectively, consecutive patients who underwent lung resection between 2008 and 2017. To investigate the safety of aspirin continuation, patients who continued taking aspirin perioperatively (Group C) were matched to other patients (Group O), using a propensity score, and bleeding outcomes were compared. To assess the effect of aspirin interruption, Group C was matched to a group of patients whose aspirin regimen was interrupted (Group I), and the postoperative complications related to thromboembolism were compared.

RESULTS

Among 3393 patients, 52 continued on aspirin (Group C) perioperatively, whereas 184 had their aspirin discontinued (Group I). Comparing the matched cohorts extracted from Group C and Group O (n = 45), there were no significant differences in bleeding outcomes. Comparing the matched cohorts extracted from Group C and Group I (n = 40), group C had fewer postoperative complications related to thromboembolism (0% vs. 7.5%, p = 0.039).

CONCLUSION

Bleeding complications did not increase by continuing aspirin, but thromboembolic complications increased when the aspirin regimen was interrupted during the perioperative period of lung resection. Thus, in the absence of a prohibitive bleeding risk, the continuation of aspirin during the perioperative period of lung resection appears to be desirable.

Dual Antiplatelet Therapy in Patients with High Cardiovascular Risk

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Stroke Thrombolysis in Patients Taking Ticagrelor -Two Successful Cases and a Review of the Literature

BACKGROUND

Ticagrelor is a novel antiplatelet agent that is frequently used for secondary prevention in coronary artery disease and has emerging evidence in stroke after the recent results of SOCRATES and THALES trials. The use of intravenous thrombolysis with alteplase in acute ischemic stroke (AIS) patients on ticagrelor is a topic of debate as the safety profile of ticagrelor in this setting is not well established.

METHODS

We identified consecutive AIS patients taking ticagrelor who received intravenous alteplase at a comprehensive stroke center from January 2016 to December 2019. We then performed a literature search to capture all known published cases of intravenous thrombolysis in stroke patients on ticagrelor.

RESULTS

Of the 3896 patients who were treated for AIS at our local comprehensive stroke center during this time period, two patients received intravenous alteplase while on ticagrelor. Both patients had posterior circulation acute strokes and were successfully treated with intravenous alteplase without a systemic or intracranial bleeding event. Only five other cases of intravenous thrombolysis in AIS patients on ticagrelor have been reported in the literature. Among these cases, four of the five cases had a hemorrhagic complication.

CONCLUSION

Despite prior reports of hemorrhagic complications with use of IV alteplase in setting of pre-treatment with ticagrelor, we report the safe use of intravenous thrombolysis in two cases presenting with acute ischemic stroke. Until safety is established in large studies, decision for thrombolysis should be made on case-by-case basis.

Investigation of the interaction between proton pump inhibitors and clopidogrel using VerifyNow P2Y12 assay

BACKGROUND

Randomized trials and observation studies have revealed conflicting results regarding the interaction between clopidogrel and proton pump inhibitors (PPIs). The aim of our study was to provide laboratory evidence regarding whether PPIs blunt the antiplatelet reactivity of clopidogrel.

METHODS

We included records of Asian patients who received clopidogrel treatment for cardiovascular or cerebrovascular events and the VerifyNow P2Y12 assay for platelet reactivity monitoring. The responsiveness of antiplatelet effect to clopidogrel was analyzed according to 3 criteria:Results: Patients treated without PPIs did not differ significantly from those concomitantly treated with PPIs in terms of levels of PI (25.7% ± 24.3% vs 23.0 ± 25.3%, P = .4315), PRU (187.3 ± 74.0 vs 197.4 ± 77.3, P = .3373), or responsiveness to antiplatelet (adjusted absolute risk, 3.5%; 95% confidence interval, - 10.7 to 17.7%; P = .6297). Patients treated with lansoprazole, esomeprazole, pantoprazole, and rabeprazole exhibited no significant differences in PRU or PI levels compared with those treated without PPIs. By contrast, patients treated with dexlansoprazole exhibited a significantly decreased level of PI (25.7% ± 24.3% vs 14.0% ± 21.6%, P = .0297) and responsiveness to clopidogrel under the criterion PI > 20% (adjusted absolute risk: 10.5%; 95% confidence interval: 2.6% to 43.6%; P = .0274).

CONCLUSION

No robust interaction between clopidogrel and PPIs was found, but caution should be exercised in the concomitant use of dexlansoprazole and clopidogrel in Asians.

The need of a multicomponent guiding approach to personalize clopidogrel treatment

Patients bearing polymorphisms termed CYP2C19 loss of function (LoF) alleles and ABCB1-C3435T may do not properly respond to standard dosage of clopidogrel and have an increased risk of thrombosis. Moreover, co-administration of proton pump inhibitors (PPIs) and clopidogrel may attenuate the antiplatelet effect. The role of pharmacogenetics and PPIs/clopidogrel drug-drug interaction has been extensively investigated in patients with acute coronary syndrome after stent implantation (ACS/PCI), while data in patients undergoing vascular surgery are scarce. Here we have performed a systematic review to evaluate the available literature in such a clinical setting and have discussed the controversies about the use of CYP2C19 pharmacogenetics and platelet function testing to personalize clopidogrel treatment. In addition, we have made a comparison of the literature data with our findings concerning patients eligible for vascular surgery and treated with clopidogrel, in whom we used a combined management based on the CYP2C19 and ABCB1 pharmacogenetic testing with monitoring of therapeutic adherence and PPIs-clopidogrel interaction. Both our data and those produced during both observational studies and randomized clinical trials confirm the validity of pharmacogenetics to personalize clopidogrel treatment and stress the importance to make a drug monitoring considering all the known variables, potentially responsible for treatment failure. However, the American Heart Association and the European Cardiovascular Society recommend against the routine use of clopidogrel pharmacogenetic testing. An update of the international guidelines on antiplatelet therapy, incorporating the evidence related to CYP2C19 pharmacogenetics and PPIs-clopidogrel drug-drug interactions is warranted both in ACS/PCI patients and subjects undergoing vascular surgery.

Ipsilateral Nonstenotic Carotid Disease in Minor Ischemic Stroke: an Exploratory Analysis of The POINT Randomized Clinical Trial

BACKGROUND AND AIM

Ipsilateral nonstenotic carotid disease is increasingly recognized as an etiology of ischemic stroke, however tailored treatment strategies are lacking. We aimed to examine clinical characteristics and treatment effects in patients with minor ischemic stroke associated with ipsilateral nonstenotic carotid disease in the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial.

METHODS

We performed an exploratory analysis of the interaction of the treatment effects of aspirin plus clopidogrel versus aspirin monotherapy, stratified by presence of ipsilateral nonstenotic carotid disease in patients with minor ischemic stroke in the POINT trial.

RESULTS

For this exploratory analysis, 167 patients presenting with ischemic stroke and ipsilateral nonstenotic carotid disease, defined as 1%-49% carotid stenosis ipsilateral to the corresponding territory of ischemic stroke, and 833 patients no carotid disease were included. Compared to patients with no carotid disease, patients with ipsilateral nonstenotic carotid disease were older (68.5 ± 11.3 years versus 61.3 ± 12.8 years; P < 0.001), and had a higher prevalence of hypertension (76.6% versus 59.2%, P < 0.001), ischemic heart disease (13.8% versus 5.4%, P < 0.001), and tobacco use (past: 34.1% versus 25.2%, P = 0.005; present: 27.5% versus 22.8%, P = 0.005). 5.4% of patients with ipsilateral nonstenotic carotid disease had recurrent ischemic stroke within 14 days. Patients receiving dual antiplatelet therapy had a numerical reduction in recurrent ischemic stroke compared to patients receiving aspirin monotherapy, however the exploratory analysis was underpowered to detect a statistically significant difference in treatment effect (HR 0.50, 95% CI 0.18-1.40, P = 0.19).

CONCLUSION

Patients with minor ischemic stroke and ipsilateral nonstenotic carotid disease had a high risk of early stroke recurrence in the POINT trial. Dual antiplatelet therapy provided a non-statistically significant reduction in recurrent ischemic stroke with no difference in safety outcomes compared to aspirin monotherapy. Further study is needed to determine if early and short duration dual antiplatelet therapy is beneficial for all patients with ipsilateral nonstenotic carotid disease.

Novel Antiplatelet Therapies for Atherothrombotic Diseases

Antiplatelet therapies are an essential tool to reduce the risk of developing clinically apparent atherothrombotic disease and are a mainstay in the therapy of patients who have established cardiovascular, cerebrovascular, and peripheral artery disease. Strategies to intensify antiplatelet regimens are limited by concomitant increases in clinically significant bleeding. The development of novel antiplatelet therapies targeting additional receptor and signaling pathways, with a focus on maintaining antiplatelet efficacy while preserving hemostasis, holds tremendous potential to improve outcomes among patients with atherothrombotic diseases.