Dual antiplatelet therapy after stroke or transient ischaemic attack - how long to treat? The duration of aspirin plus clopidogrel in stroke or transient ischaemic attack: a systematic review and meta-analysis

Time Course for Benefit and Risk of Ticagrelor and Aspirin in Acute Ischemic Stroke or Transient Ischemic Attack

OBJECTIVES

To investigate the short-term time course benefit and risk of ticagrelor with aspirin in acute mild-moderate ischemic stroke or high-risk transient ischemic attack (TIA) in the THALES (The Acute Stroke or Transient Ischemic Attack Treated with Ticagrelor and ASA for Prevention of Stroke and Death) trial.

METHODS

In an exploratory analysis of the THALES trial, we evaluated the cumulative incidence of irreversible efficacy and safety outcomes at different timepoints during the 30-day treatment period. The efficacy outcome was major ischemic events defined as a composite of ischemic stroke or non-hemorrhagic death. The safety outcome was major hemorrhage defined as a composite of intracranial hemorrhage and fatal bleedings. Net clinical impact was defined as the combination of these two endpoints.

RESULTS

This analysis included a total of 11,016 patients (5523 in the ticagrelor-aspirin group and 5493 in the aspirin group) with mean age of 65 years, and 39% were women. The reduction of major ischemic events by ticagrelor occurred in the first week (4.1% vs 5.3%; absolute risk reduction 1.15%, 95% CI 0.36% to 1.94%), and remained throughout the 30-day treatment period. An increase in major hemorrhage was seen during the first week and remained relatively constant in the following weeks (absolute risk increase, approximately 0.3%). Cumulative analysis showed that the net clinical impact favored ticagrelor-aspirin in the first week (absolute risk reduction 0.97%, 95% CI, 0.17% to 1.77%) and remained constant throughout the 30 days.

DISCUSSION

In patients with mild-moderate ischemic stroke or high-risk TIA, the treatment effect of ticagrelor-aspirin was present from the first week. The ischemic benefit of ticagrelor-aspirin outweighs the risk of major hemorrhage throughout the treatment period, which may support the use of 30 days treatment with ticagrelor and aspirin in these patients.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with mild-moderate ischemic stroke or high-risk TIA, the ischemic benefit of ticagrelor-aspirin outweighs the risk of major hemorrhage throughout the 30-day treatment period.

Towards personalized antithrombotic management with drugs and devices across the cardiovascular spectrum

Intravascular thrombus formation and embolization are among the most frequent events leading to a number of cardiovascular conditions with high morbidity and mortality. The underlying causes are stasis of the circulating blood, genetic and acquired coagulation disorders, and reduced antithrombotic or prothrombotic properties of the vascular wall (Virchow's triad). In the venous system, intravascular thrombi can cause venous thrombosis and pulmonary and even peripheral embolism including ischaemic stroke [through a patent foramen ovale (PFO)]. Thrombi in the left atrium and its appendage or ventricle form in the context of atrial fibrillation and infarction, respectively. Furthermore, thrombi can form on native or prosthetic aortic valves, within the aorta (in particular at sites of ulcers, aortic dissection, and abdominal aneurysms), and in cerebral and peripheral arteries causing stroke and critical limb ischaemia, respectively. Finally, thrombotic occlusion may occur in arteries supplying vital organs such the heart, brain, kidney, and extremities. Thrombus formation and embolization can be managed with anticoagulants and devices depending on where they form and embolize and on patient characteristics. Vitamin K antagonists are preferred in patients with mechanical valves, while novel oral anticoagulants are first choice in most other cardiovascular conditions, in particular venous thromboembolism and atrial fibrillation. As anticoagulants are associated with a risk of bleeding, devices such as occluders of a PFO or the left atrial appendage are preferred in patients with an increased bleeding risk. Platelet inhibitors such as aspirin and/or P2Y12 antagonists are preferred in the secondary prevention of coronary artery disease, stroke, and peripheral artery disease either alone or in combination depending on the clinical condition. A differential and personalized use of anticoagulants, platelet inhibitors, and devices is recommended and reviewed in this article.

[Current opportunities for secondary prevention of atherothrombotic stroke]

The article is devoted to an urgent medical and social problem - secondary prevention of atherothrombotic stroke and contains current evidence on the use of combined antiplatelet and anticoagulant therapy. In the COMPASS study, the dual-pathway thrombosis inhibition scheme using rivaroxaban in combination with acetylsalicylic acid (ASA) compared with ASA monotherapy demonstrated in patients with established atherosclerotic diseases of the circulatory system, a decrease in the total risk of stroke, death from cardiovascular causes and myocardial infarction by 24%; reduced risk of recurrent stroke by 67%. The incidence of repeated ischemic stroke (IS) in the combination therapy group was 1.1% per year, in the ASA group - 3.4% per year. The total incidence of adverse outcomes included in the combined indicator «net clinical benefit» in the rivaroxaban group in combination with ASA was 20% lower than in the ASA group and confirms the advantages of combination therapy in the prevention of recurrent noncardioembolic IS.

Impact of multiple cardiovascular medications on mortality after an incidence of ischemic stroke or transient ischemic attack

BACKGROUND

To manage the risk factors and to improve clinical outcomes, patients with stroke commonly receive multiple cardiovascular medications. However, there is a lack of evidence on the optimum combination of medication therapy in the primary care setting after ischemic stroke. Therefore, this study aimed to investigate the effect of multiple cardiovascular medications on long-term survival after an incident stroke event (ischemic stroke or transient ischemic attack (TIA)).

METHODS

This study consisted of 52,619 patients aged 45 and above with an incident stroke event between 2007 and 2016 in The Health Improvement Network database. We estimated the risk of all-cause mortality in patients with multiple cardiovascular medications versus monotherapy using a marginal structural model.

RESULTS

During an average follow-up of 3.6 years, there were 9230 deaths (7635 in multiple cardiovascular medication groups and 1595 in the monotherapy group). Compared with patients prescribed monotherapy only, the HRs of mortality were 0.82 (95% CI 0.75-0.89) for two medications, 0.65 (0.59-0.70) for three medications, 0.61 (0.56-0.67) for four medications, 0.60 (0.54-0.66) for five medications and 0.66 (0.59-0.74) for ≥ six medications. Patients with any four classes of antiplatelet agents (APAs), lipid-regulating medications (LRMs), angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs), beta-blockers, diuretics and calcium channel blockers (CCBs) had the lowest risk of mortality (HR 0.51, 95% CI 0.46-0.57) versus any one class. The combination containing APAs, LRMs, ACEIs/ARBs and CCBs was associated with a 61% (95% CI 53-68%) lower risk of mortality compared with APAs alone.

CONCLUSION

Our results suggested that combination therapy of four or five cardiovascular medications may be optimal to improve long-term survival after incident ischemic stroke or TIA. APAs, LRMs, ACEIs/ARBs and CCBs were the optimal constituents of combination therapy in the present study.

[The new Epoch of Antithrombotic Therapy in the Long-Term Prevention of a non-Cardioembolic Stroke]

This article presents current opinions on the role of antithrombotic therapy in secondary prevention of cardiovascular diseases (CVD) in patients after noncardioembolic stroke or a transient ischemic attack on the background of sinus rhythm. This review analytically analyses evidence-based data on antithrombotic drugs used for this secondary prevention. Despite the fact that acetylsalicylic acid (ASA) is still a "gold standard" for prevention of noncardioembolic stroke, the search for rational combinations of antithrombotic drugs to increase the effectiveness of preventive treatment is relevant. The question whether the rivaroxaban treatment as monotherapy or in combination with ASA is more effective than the ASA monotherapy for secondary prevention of cardiovascular complications (CVC) was addressed in the COMPASS study. In that study, three regimens of antithrombotic therapy were compared in patients with stable atherosclerotic CVD: rivaroxaban (2.5 mg twice a day) in combination with ASA (100 mg/day); rivaroxaban (5 mg twice a day); and ASA (100 mg/day). Risk for development of major CVC (death, stroke, myocardial infarction (IM)) was lower (p<0.001) in the rivaroxaban+ASA combination treatment group than in the ASA monotherapy group; however, the risk of major bleedings was somewhat higher. Total risk based on the definition of "pure clinical benefit" was lower for the rivaroxaban+ASA combination treatment than for the ASA monotherapy. The rivaroxaban monotherapy did not result in a significant decrease in the risk of major CVC compared to the ASA monotherapy but significantly increased the risk of major bleedings. Incidence of repeated ischemic stroke for a year was 1.1% for the combination therapy, 2.6% for the rivaroxaban therapy, and 3.4% for the ASA monotherapy with significant differences between the combination treatment group and the ASA monotherapy group (p<0.01). Relative risk of repeated stroke was 67% lower for the combination therapy group compared to the ASA monotherapy group. The combination of rivaroxaban (2.5 mg twice a day) and ASA (100 mg) opens a new epoch of antithrombotic treatment for primary and secondary prevention of stroke in patients with a stable atherosclerotic CVD and sinus rhythm.

The Role of Clopidogrel in 2020: A Reappraisal

Antiplatelet therapy is the mainstay of treatment and secondary prevention of cardiovascular disease (CVD), including acute coronary syndrome (ACS), transient ischemic attack (TIA) or minor stroke, and peripheral artery disease (PAD). The P2Y12 inhibitors, of which clopidogrel was the first, play an integral role in antiplatelet therapy and therefore in the treatment and secondary prevention of CVD. This review discusses the available evidence concerning antiplatelet therapy in patients with CVD, with a focus on the role of clopidogrel. In combination with aspirin, clopidogrel is often used as part of dual antiplatelet therapy (DAPT) for the secondary prevention of ACS. Although newer, more potent P2Y12 inhibitors (prasugrel and ticagrelor) show a greater reduction in ischemic risk compared with clopidogrel in randomized trials of ACS patients, these newer P2Y12 inhibitors are often associated with an increased risk of bleeding. Deescalation of DAPT by switching from prasugrel or ticagrelor to clopidogrel may be required in some patients with ACS. Furthermore, real-world studies of ACS patients have not confirmed the benefits of the newer P2Y12 inhibitors over clopidogrel. In patients with very high-risk TIA or stroke, short-term DAPT with clopidogrel plus aspirin for 21-28 days, followed by clopidogrel monotherapy for up to 90 days, is recommended. Clopidogrel monotherapy may also be used in patients with symptomatic PAD. In conclusion, there is strong evidence supporting the use of clopidogrel antiplatelet therapy in several clinical settings, which emphasizes the importance of this medication in clinical practice.

Proposed antithrombotic strategy for acute ischemic stroke with large-artery atherosclerosis: focus on patients with high-risk transient ischemic attack and mild-to-moderate stroke

An effective antithrombotic strategy is required to prevent the recurrence and aggravation of large-artery atherosclerosis (LAA) stroke, especially in high-risk transient ischemic attack (TIA) and acute mild ischemic stroke. Based on clinical evidence, atherosclerotic thrombosis theory, antithrombotic treatment guidelines of acute myocardial infarction (AMI), and previous studies, a new antithrombotic strategy "early administration, enhanced therapy, combination therapy, short-term therapy, and sequential therapy" was proposed in this study. Multicenter randomized trials are needed in the future to verify the efficacy of the strategy.

Aspirin plus clopidogrel versus aspirin mono-therapy for ischemic stroke: a meta-analysis

Objectives. Stroke is a common condition after a transient ischemic attack (TIA) or minor ischemic stroke (IS). Adding clopidogrel to aspirin may yield more beneficial outcomes than aspirin mono-therapy; meanwhile, the risk of bleeding in the acute phase remains poorly understood. Therefore, there is increasing emphasis on the risks and benefits of clopidogrel with aspirin compared with aspirin mono-therapy in an effort to treat TIA/IS. Design. We searched several electronic databases, including PubMed, Cochrane, and Embase, to identify eligible randomized controlled trials (RCTs) based on the index words comparing dual-antiplatelet therapy to aspirin mono-therapy for secondary stroke prevention updated to December, 2018. Results. A total of 11 RCTs met our inclusion criteria. The pooled analysis showed that clopidogrel plus aspirin was associated with a trend toward a reduction in recurrent IS (RR = 0.72, 95%CI = 0.65-0.81, p < .001), but not the recurrent stroke rate (RR = 0.81, 95% CI = 0.63-1.03, p = .09) than aspirin mono-therapy. There were differences in bleeding episodes (RR = 1.81, 95%CI = 1.65-1.99, p < .001), moderate-severe major bleeding (RR = 1.64, 95% CI = 1.24-2.16, p = .0005), or mild bleeding (RR = 2.25, 95%CI = 1.54-3.31, p < .001) between the study groups. Meanwhile, no benefit of reducing the risk of intracranial hemorrhage with dual-antiplatelet therapy was found in TIA/IS patients (RR = 1.44, 95% CI = 0.95-2.19, p = .09). Conclusions. The addition of clopidogrel to aspirin for patients with TIA or IS appeared to significantly reduce the risk of IS recurrence with a possible increase in the risk of bleeding compared with aspirin alone.

Antiplatelet Therapy in Acute Mild-Moderate Ischemic Stroke (ATAMIS): a parallel, randomised, open-label, multicentre, prospective study

Background

A recent study shows that dual antiplatelet therapy with clopidogrel plus aspirin is superior to aspirin monotherapy for minor stroke, which is defined as a National Institutes of Health Stroke Scale (NIHSS)score of ≤3. However, acute mild-moderate ischaemic stroke (4≤NIHSS≤10) still needs aggressive antiplatelet intervention to prevent deterioration and recurrence of stroke. The efficacy and safety of dual antiplatelet therapy versus aspirin monotherapy in the population are not clear. A multicentre clinical trial is designed to evaluate the efficacy and safety of clopidogrel plus aspirin therapy versus aspirin monotherapy within 48 hours of symptom onset of mild-moderate ischaemic stroke.

Methods/Design

The study is a randomised, open-label, multicentre, prospective trial with a target enrolment of 2700 patients from 60 centres in Northeast China. A treatment allocation identification number to each enrolled patient will be provided by a random number generator. The follow-up time for the clopidogrel plus aspirin and aspirin monotherapy groups is 90 days. The primary efficacy endpoint is a stroke progression event, which is defined as ≥4 point increase in the NIHSS score in 48 hours. The second efficacy endpoints include new ischaemic stroke within 90 days, change in the NIHSS score within 14 days, modified Rankin Scale score on day 90 and other vascular or death events within 90 days. The safety endpoints include mucocutaneous haemorrhage, organ haemorrhage and intracranial haemorrhage, adverse events and severe adverse events. χ² test, t-test (or Mann-Whitney test), survival analysis and Cox proportional hazards models will be conducted. The findings of the study may provide an important evidence for clinical practice for these patients.

Discussion

The trial will be conducted under a rational design and will provide valuable evidence on the appropriate treatment for this population.

Ethics and dissemination

The study was reviewed and approved by the Ethics Committee of the General Hospital of Shen-Yang Military Region (no K(2016) 6).

Trial registration number

NCT02869009; Pre-results.

Clinical significances and features of prompt brain CT scan after intracranial artery stenting: analysis of 501 cases

Cerebral hemorrhage is a serious complication of intracranial artery stenting that could be fatal without timely identification and treatment. Prompt brain CT scan would help to evaluate whether cerebral hemorrhage occurs, however, the diverse features of the CT scan immediately after stenting could influence the judgement sometimes. Therefore, we analyzed and summarized these features to help to determine the clinical significance of these CT features. The prompt CT features after stenting were classified into three types. Type I indicates that no high-density shadows. Type II indicates that high-density shadows scattered in the infarct areas and/or subarachnoid spaces without mass effect. Type III indicates high-density shadows scattered in and/or out of the infarct areas and/or subarachnoid space with obvious mass effects. Based on this classification, the patients in both Type I and II would continue the double anti-platelet treatment (DAPT) and anti-coagulation treatment, while the later need closer monitoring. However, patients in Type III must immediately withdraw the DAPT and anti-coagulation treatment with close monitoring and surgical intervention was needed when necessary. Nineteen (3.79%) patients were classified into Type III, and 5 (1.00%) of the 19 were accepted surgical intervention. Two of these patients died (0.40%). The prompt CT scan timely distinguishing the cerebral hemorrhage was necessary after intracranial artery stent angioplasty. Additionally, based on the different prompt CT features to take different therapeutic strategies after stenting would achieve better outcomes for ischemic stroke or transient ischemic stroke (TIA) patients underwent intracranial artery endovascular therapy.

Canadian stroke best practice recommendations: Secondary prevention of stroke, sixth edition practice guidelines, update 2017

The 2017 update of The Canadian Stroke Best Practice Recommendations for the Secondary Prevention of Stroke is a collection of current evidence-based recommendations intended for use by clinicians across a wide range of settings. The goal is to provide guidance for the prevention of ischemic stroke recurrence through the identification and management of modifiable vascular risk factors. Recommendations include those related to diagnostic testing, diet and lifestyle, smoking, hypertension, hyperlipidemia, diabetes, antiplatelet and anticoagulant therapies, carotid artery disease, atrial fibrillation, and other cardiac conditions. Notable changes in this sixth edition include the development of core elements for delivering secondary stroke prevention services, the addition of a section on cervical artery dissection, new recommendations regarding the management of patent foramen ovale, and the removal of the recommendations on management of sleep apnea. The Canadian Stroke Best Practice Recommendations include a range of supporting materials such as implementation resources to facilitate the adoption of evidence to practice, and related performance measures to enable monitoring of uptake and effectiveness of the recommendations. The guidelines further emphasize the need for a systems approach to stroke care, involving an interprofessional team, with access to specialists regardless of patient location, and the need to overcome geographic barriers to ensure equity in access within a universal health care system.

Anti-GPVI Fab SAR264565 effectively blocks GPVI function in ex vivo human platelets under arterial shear in a perfusion chamber

INTRODUCTION

Glycoprotein VI (GPVI) is the major platelet receptor for collagen-mediated platelet adhesion and activation. SAR264565 is an anti-GPVI-Fab, binds to GPVI with high affinity, and blocks GPVI function in human platelets in vitro.

METHODS

The effect of SAR26456 on platelet responsiveness in the blood of 21 healthy male subjects was investigated using Sakariassen's ex vivo thrombogenesis perfusion chamber model on a collagen-coated surface under conditions mimicking arterial flow. Ex vivo effects of SAR264565 (10 and 100 μg/mL) were investigated before administration of aspirin or clopidogrel to study subjects (baseline), after aspirin (2× 300 mg) administration alone, and after combined aspirin (2× 300 mg)/clopidogrel (600 mg) administration. Additional ex vivo and in vitro platelet tests were also performed.

RESULTS

Addition of SAR264565 to the perfusion chamber dose-dependently reduced platelet and fibrin deposition, reaching statistical significance at 100 μg/mL (415 ± 67 compared to 137 ± 36 platelets/cm², [p < 0.01] and fibrin 0.095 ± 0.014 compared to 0.032 ± 0.008 μg/cm², [p < 0.001]). Aspirin administration caused an additive and dose-dependent reduction of SAR264565-induced platelet and fibrin deposition. Combined aspirin/clopidogrel administration did not lead to additional SAR264565-induced inhibition of platelet or fibrin deposition.

CONCLUSION

GPVI antagonism by the anti-GPVI-Fab fragment SAR264565 dose-dependently inhibits platelet adhesion and fibrin formation on a collagen surface under arterial shear. Additive inhibition is observed after prior aspirin administration with no further amplification on top of a combination of aspirin with clopidogrel. Ex vivo antiplatelet tests confirmed a selective inhibiting effect of SAR264565 on collagen-induced platelet activation.

Risks and benefits of clopidogrel–aspirin in minor stroke or TIA

Objective:

To investigate the short-term time course risks and benefits of clopidogrel with aspirin in minor ischemic stroke or TIA.

Methods:

Data were derived from the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. The primary outcome was a new ischemic stroke. Safety outcomes included any bleeding and moderate to severe bleeding. Time course analyses were performed for the outcomes of both stroke and bleeding.

Results:

A total of 145 (71.1%), 13 (6.4%), and 12 (5.9%) of 204 new ischemic strokes in the clopidogrel–aspirin group vs 223 (75.6%), 19 (6.4%), and 8 (2.7%) of 295 in the aspirin alone group occurred at the first, second, and third week, respectively. A total of 23 (38.3%), 15 (25.0%), and 9 (15.0%) of 60 bleeding cases in the clopidogrel–aspirin group vs 15 (36.6%), 8 (19.5%), and 3 (7.3%) of 41 in the aspirin alone group occurred at the first, second, and third week, respectively. Clopidogrel–aspirin treatment numerically reduced the risk of ischemic stroke within the first 2 weeks. From the 10th day, the number of any bleeding cases caused by dual antiplatelets outweighed that of new stroke reduced by dual antiplatelets.

Conclusions:

Clopidogrel–aspirin treatment may have a benefit of reducing stroke risk outweighing the potential risk of increased bleeding especially within the first 2 weeks compared with aspirin alone in patients with minor stroke or TIA.

Clinicaltrials.gov identifier:

NCT00979589.

Classification of evidence:

This study provides Class II evidence that for patients with minor stroke or TIA, the reduction of stroke risk from clopidogrel plus aspirin within the first 2 weeks outweighs the risk of bleeding compared with aspirin alone.