"AICLA" controlled trial of aspirin and dipyridamole in the secondary prevention of athero-thrombotic cerebral ischemia

Efficacy and safety of antiplatelet therapy for secondary prevention of small subcortical infarction: A systematic review and network meta-analysis

PURPOSE

Small subcortical infarction (SSI) accounts for approximately 25% of ischemic strokes and shares a comparable recurrence rate of cardiovascular events with other stroke subtypes. This study aimed to evaluate the efficacy and safety of various antiplatelet for secondary prevention of SSI by network meta-analysis (NMA).

METHODS

We systematically searched Medline, Embase, Cochrane Library, and Web of Science from inception to October 2024 for randomized controlled trials (RCTs). Efficacy outcomes included: incidence of major adverse cardiovascular events (MACEs), rates of any stroke and ischemic stroke recurrence. Safety outcomes included: incidence of intracranial hemorrhage, severe bleeding, any bleeding events, and mortality.

FINDINGS

A total of 24 RCTs involving 47,507 SSI patients were included in systematic review. The NMA included 19 RCTs (39,137 patients). The NMA demonstrated that Cilostazol showed the best efficacy in preventing MACEs (surface under the cumulative ranking curve (SUCRA): 90.0%). cilostazol significantly reduced the incidence of MACEs compared to aspirin (OR, 0.66; 95% CI, 0.49-0.89), ticlopidine (OR, 0.65; 95% CI, 0.43-1.00), dipyridamole (OR, 0.61; 95% CI, 0.42-0.90), vorapaxar (OR, 0.51; 95% CI, 0.35-0.74), Sarpogrelate (OR, 0.62; 95% CI, 0.40-0.97), and placebo (OR, 0.51; 95% CI, 0.37-0.71). Regarding safety, aspirin plus clopidogrel and vorapaxar was associated with a significantly increased risk of severe bleeding events compared to the control.

DISCUSSION AND CONCLUSIONS

Cilostazol may be the most effective agent for preventing cardiovascular event recurrence. Aspirin plus clopidogrel and vorapaxar may be not recommended due to heightened bleeding risks.

REGISTRATION

International prospective register of systematic reviews (PROSPERO) - CRD42024607819.

Prophylactic Effect of Aspirin and Other Medicine on Cerebral Infarction for Patients with Cardiovascular Diseases Risk Factors: A Systemic Review and Meta-Analysis

Stroke, as a type of cardiovascular disease (CVD) and cerebrovascular disease, has the risk of causing death or disability in patients. Aspirin, as an antipyretic and analgesic drug, can also treat or prevent CVDs. Previous studies have had conflicting results on the preventive effect of aspirin on cerebral infarction for patients with CVD risk factors. This review was carried out through a meticulous search of the Web of Science and PubMed databases. Articles were included or excluded based on predefined criteria. In terms of heterogeneity, a fixed effect model was utilized when I2 was less than 50%. Conversely, if the studies were deemed clinically comparable, a random effect model was implemented. The findings suggest that medical intervention significantly mitigates the risk of cerebral infarction in patients predisposed to CVDs [odds ratio (OR), 0.85; 95% confidence interval (CI), 0.74-0.98; P = 0.03]. Interestingly, the preventive efficacy of medication appears to be higher in men (OR, 0.82; 95% CI, 0.72-0.94; P = 0.004) than in women (OR, 0.84; 95% CI, 0.69-1.01; P = 0.06). However, in terms of stroke prevention, no significant difference was observed between the use of aspirin (OR, 0.90; 95% CI, 0.76-1.06; P = 0.19) and other medications (OR, 0.65; 95% CI, 0.31-1.38; P = 0.26).

Molecular Mechanisms of Ischemic Stroke: A Review Integrating Clinical Imaging and Therapeutic Perspectives

Ischemic stroke poses a significant global health challenge, necessitating ongoing exploration of its pathophysiology and treatment strategies. This comprehensive review integrates various aspects of ischemic stroke research, emphasizing crucial mechanisms, therapeutic approaches, and the role of clinical imaging in disease management. It discusses the multifaceted role of Netrin-1, highlighting its potential in promoting neurovascular repair and mitigating post-stroke neurological decline. It also examines the impact of blood-brain barrier permeability on stroke outcomes and explores alternative therapeutic targets such as statins and sphingosine-1-phosphate signaling. Neurocardiology investigations underscore the contribution of cardiac factors to post-stroke mortality, emphasizing the importance of understanding the brain-heart axis for targeted interventions. Additionally, the review advocates for early reperfusion and neuroprotective agents to counter-time-dependent excitotoxicity and inflammation, aiming to preserve tissue viability. Advanced imaging techniques, including DWI, PI, and MR angiography, are discussed for their role in evaluating ischemic penumbra evolution and guiding therapeutic decisions. By integrating molecular insights with imaging modalities, this interdisciplinary approach enhances our understanding of ischemic stroke and offers promising avenues for future research and clinical interventions to improve patient outcomes.

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

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

Antiplatelet therapy for secondary prevention of lacunar stroke: a systematic review and network meta-analysis

PURPOSE

To comprehensively compare the efficacy of different antiplatelet therapies for secondary prevention of lacunar stroke (LS).

METHODS

The relevant studies were identified by searching PubMed, EMBASE, Web of Science, and Cochrane Collaboration Database up to May 2022. Cardiovascular and cerebrovascular events were chosen to evaluate the efficacy of antiplatelet therapy for secondary prevention. Loop-specific approach and node-splitting analysis were used to evaluate consistency and inconsistency, respectively. The value of the surface under the cumulative ranking (SUCRA) was calculated and ranked. Funnel-plot symmetry was used to evaluate publication bias. The meta-analysis was performed by using STATA 16.0.

RESULTS

Thirteen studies with a total of 33,011 subjects were included in this network meta-analysis. Compared with placebo, aspirin, clopidogrel, cilostazol, ticlopidine, aspirin plus dipyridamole, and aspirin plus clopidogrel were associated with reducing cardiovascular and cerebrovascular events. The SUCRA estimated relative ranking of treatments showed that cilostazol may be the most effective (RR 0.56, 95% CI 0.42-0.74, SUCRA 95.8). No significant inconsistency or publication bias was found in the study.

CONCLUSIONS

This meta-analysis suggests that cilostazol may be a priority option for secondary prevention of patients with LS. These findings still need further study in the future.

An Improved Detection Algorithm for Ischemic Stroke NCCT Based on YOLOv5

Cerebral stroke (CS) is a heterogeneous syndrome caused by multiple disease mechanisms. Ischemic stroke (IS) is a subtype of CS that causes a disruption of cerebral blood flow with subsequent tissue damage. Noncontrast computer tomography (NCCT) is one of the most important IS detection methods. It is difficult to select the features of IS CT within computational image analysis. In this paper, we propose AC-YOLOv5, which is an improved detection algorithm for IS. The algorithm amplifies the features of IS via an NCCT image based on adaptive local region contrast enhancement, which then detects the region of interest via YOLOv5, which is one of the best detection algorithms at present. The proposed algorithm was tested on two datasets, and seven control group experiments were added, including popular detection algorithms at present and other detection algorithms based on image enhancement. The experimental results show that the proposed algorithm has a high accuracy (94.1% and 91.7%) and recall (85.3% and 88.6%) rate; the recall result is especially notable. This proves the excellent performance of the accuracy, robustness, and generalizability of the algorithm.

European Stroke Organisation (ESO) guideline on pharmacological interventions for long-term secondary prevention after ischaemic stroke or transient ischaemic attack

Recurrent stroke affects 9% to 15% of people within 1 year. This European Stroke Organisation (ESO) guideline provides evidence-based recommendations on pharmacological management of blood pressure (BP), diabetes mellitus, lipid levels and antiplatelet therapy for the prevention of recurrent stroke and other important outcomes in people with ischaemic stroke or transient ischaemic attack (TIA). It does not cover interventions for specific causes of stroke, including anticoagulation for cardioembolic stroke, which are addressed in other guidelines. This guideline was developed through ESO standard operating procedures and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The working group identified clinical questions, selected outcomes, performed systematic reviews, with meta-analyses where appropriate, and made evidence-based recommendations, with expert consensus statements where evidence was insufficient to support a recommendation. To reduce the long-term risk of recurrent stroke or other important outcomes after ischaemic stroke or TIA, we recommend: BP lowering treatment to a target of <130/80 mmHg, except in subgroups at increased risk of harm; HMGCoA-reductase inhibitors (statins) and targeting a low density lipoprotein level of <1.8 mmol/l (70 mg/dl); avoidance of dual antiplatelet therapy with aspirin and clopidogrel after the first 90 days; to not give direct oral anticoagulant drugs (DOACs) for embolic stroke of undetermined source and to consider pioglitazone in people with diabetes or insulin resistance, after careful consideration of potential risks. In addition to the evidence-based recommendations, all or the majority of working group members supported: out-of-office BP monitoring; use of combination treatment for BP control; consideration of ezetimibe or PCSK9 inhibitors when lipid targets are not achieved; consideration of use of low-dose DOACs in addition to an antiplatelet in selected groups of people with coronary or peripheral artery disease and aiming for an HbA1c level of <53 mmol/mol (7%) in people with diabetes mellitus. These guidelines aim to standardise long-term pharmacological treatment to reduce the burden of recurrent stroke in Europe.

Fifty Years of Acute Ischemic Stroke Treatment: A Personal History

BACKGROUND

It has been 50 years since the first explorations of the physiology of cerebral ischemia by measuring cerebral blood flow (CBF), and 25 years since the approval of tissue plasminogen activator for treating acute ischemic stroke. My personal career began and matured during those eras. Here, I provide my perspective on the evolution of acute stroke research and treatment from 1971 to the present, with some in-depth discussion of the National Institutes of Neurologic Disease and Stroke (NINDS) tissue-type plasminogen activator (tPA) stroke trial and development of mobile stroke units.

SUMMARY

Studies of CBF and metabolism in acute stroke patients revealed graded tissue injury that was dependent on the duration of ischemia. Subsequent animal research unraveled the biochemical cascade of events occurring at the cellular level after cerebral ischemia. After a decade of failed translation, the development of a relatively safe thrombolytic allowed us to achieve reperfusion and apply the lessons from earlier research to achieve positive clinical results. The successful conduct of the NINDS tPA stroke study coupled with positive outcomes from companion tPA studies around the world created the specialty of vascular neurology. This was followed by an avalanche of research in imaging, a focus on enhancing reperfusion through thrombectomy, and improving delivery of faster treatment culminating in mobile stroke units. Key Messages: The last half century has seen the birth and evolution of successful acute stroke treatment. More research is needed in developing new drugs and catheters to build on the advances we have already made with reperfusion and also in evolving our systems of care to get more patients treated more quickly in the prehospital setting. The history of stroke treatment over the last 50 years exemplifies that medical "science" is an evolving discipline worth an entire career's dedication. What was impossible 50 years ago is today's standard of care, what we claim as dogma today will be laughed at a decade from now, and what appears currently impossible will be tomorrow's realities.

Antithrombotic therapies in aortic and peripheral arterial diseases in 2021: a consensus document from the ESC working group on aorta and peripheral vascular diseases, the ESC working group on thrombosis, and the ESC working group on cardiovascular pharmacotherapy

The aim of this collaborative document is to provide an update for clinicians on best antithrombotic strategies in patients with aortic and/or peripheral arterial diseases. Antithrombotic therapy is a pillar of optimal medical treatment for these patients at very high cardiovascular risk. While the number of trials on antithrombotic therapies in patients with aortic or peripheral arterial diseases is substantially smaller than for those with coronary artery disease, recent evidence deserves to be incorporated into clinical practice. In the absence of specific indications for chronic oral anticoagulation due to concomitant cardiovascular disease, a single antiplatelet agent is the basis for long-term antithrombotic treatment in patients with aortic or peripheral arterial diseases. Its association with another antiplatelet agent or low-dose anticoagulants will be discussed, based on patient's ischaemic and bleeding risk as well therapeutic paths (e.g. endovascular therapy). This consensus document aims to provide a guidance for antithrombotic therapy according to arterial disease localizations and clinical presentation. However, it cannot substitute multidisciplinary team discussions, which are particularly important in patients with uncertain ischaemic/bleeding balance. Importantly, since this balance evolves over time in an individual patient, a regular reassessment of the antithrombotic therapy is of paramount importance.

Antithrombotic Therapy for Secondary Prevention in Patients with Non-Cardioembolic Stroke or Transient Ischemic Attack: A Systematic Review

Stroke embodies one of the leading causes of death and disability worldwide. We aimed to provide a comprehensive insight into the effectiveness and safety of antiplatelet agents and anticoagulants in the secondary prevention of ischemic stroke or transient ischemic attack. A systematic search for randomized controlled trials, comparing antiplatelet or anticoagulant therapy versus aspirin or placebo among patients with ischemic stroke or transient ischemic attack, was performed in order to summarize data regarding the different regimens. Keyword-based searches in the MEDLINE, EMBASE, and Cochrane Library databases were conducted until the 1st of January 2021. Our search explored 46 randomized controlled trials involving ten antiplatelet agents, six combinations with aspirin, and four anticoagulant therapies. The review of the literature reflects that antiplatelet therapy improves outcome in patients with ischemic stroke or transient ischemic attack. Monotherapy proved to be an effective and safe choice, especially in patients with a high risk of bleeding. Intensified antiplatelet regimens further improve stroke recurrence; however, bleeding rate increases while mortality remains unaffected. Supplementing the clinical judgment of stroke treatment, assessment of bleeding risk is warranted to identify patients with the highest benefit of treatment intensification.

Aspirin in the Prevention of Cardiovascular Disease and Cancer

More than a century after its synthesis, daily aspirin, given at a low dose, is a milestone treatment for the secondary prevention of cardiovascular disease (CVD). Its role in primary prevention of CVD is still debated. Older randomized controlled trials showed that aspirin reduced the low incidence of myocardial infarction but correspondingly increased the low incidence of serious gastrointestinal bleeds without altering mortality. More recent trials see the benefit attenuated, perhaps obscured by other cardioprotective practices, while the bleeding risk remains, especially in older patients. Indirect evidence, both preclinical and clinical, suggests that aspirin may protect against sporadic colorectal cancer and perhaps other cancers. However, further studies are still necessary to warrant the consumption of aspirin for primary prevention of CVD and cancer by apparently healthy individuals.

Management of carotid stenosis for primary and secondary prevention of stroke: state-of-the-art 2020: a critical review

Carotid atherosclerotic plaque is encountered frequently in patients at high cardiovascular risk, especially in the elderly. When plaque reaches 50% of carotid lumen, it induces haemodynamically significant carotid stenosis, for which management is currently at a turning point. Improved control of blood pressure, smoking ban campaigns, and the widespread use of statins have reduced the risk of cerebral infarction to <1% per year. However, about 15% of strokes are still secondary to a carotid stenosis, which can potentially be detected by effective imaging techniques. For symptomatic carotid stenosis, current ESC guidelines put a threshold of 70% for formal indication for revascularization. A revascularization should be discussed for symptomatic stenosis over 50% and for asymptomatic carotid stenosis over 60%. This evaluation should be performed by ultrasound as a first-line examination. As a complement, computed tomography angiography (CTA) and/or magnetic resonance angiography are recommended for evaluating the extent and severity of extracranial carotid stenosis. In perspective, new high-risk markers are currently being developed using markers of plaque neovascularization, plaque inflammation, or plaque tissue stiffness. Medical management of patient with carotid stenosis is always warranted and applied to any patient with atheromatous lesions. Best medical therapy is based on cardiovascular risk factors correction, including lifestyle intervention and a pharmacological treatment. It is based on the tri-therapy strategy with antiplatelet, statins, and ACE inhibitors. The indications for carotid endarterectomy (CEA) and carotid artery stenting (CAS) are similar: for symptomatic patients (recent stroke or transient ischaemic attack ) if stenosis >50%; for asymptomatic patients: tight stenosis (>60%) and a perceived high long-term risk of stroke (determined mainly by imaging criteria). Choice of procedure may be influenced by anatomy (high stenosis, difficult CAS or CEA access, incomplete circle of Willis), prior illness or treatment (radiotherapy, other neck surgery), or patient risk (unable to lie flat, poor AHA assessment). In conclusion, neither systematic nor abandoned, the place of carotid revascularization must necessarily be limited to the plaques at highest risk, leaving a large place for optimized medical treatment as first line management. An evaluation of the value of performing endarterectomy on plaques considered to be at high risk is currently underway in the ACTRIS and CREST 2 studies. These studies, along with the next result of ACST-2 trial, will provide us a more precise strategy in case of carotid stenosis.

Multiple versus fewer antiplatelet agents for preventing early recurrence after ischaemic stroke or transient ischaemic attack

BACKGROUND

Stroke is a leading cause of morbidity and mortality worldwide. Antiplatelet agents are considered to be the cornerstone for secondary prevention of stroke, but the role of using multiple antiplatelet agents early after stroke or transient ischaemic attack (TIA) to improve outcomes has not been established.

OBJECTIVES

To determine the effectiveness and safety of initiating, within 72 hours after an ischaemic stroke or TIA, multiple antiplatelet agents versus fewer antiplatelet agents to prevent stroke recurrence. The analysis explores the evidence for different drug combinations.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched 6 July 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 7 of 12, 2020) (last searched 6 July 2020), MEDLINE Ovid (from 1946 to 6 July 2020), Embase (1980 to 6 July 2020), ClinicalTrials.gov, and the WHO ICTRP. We also searched the reference lists of identified studies and reviews and used the Science Citation Index Cited Reference search for forward tracking of included studies.

SELECTION CRITERIA

We selected all randomised controlled trials (RCTs) that compared the use of multiple versus fewer antiplatelet agents initiated within 72 hours after stroke or TIA.

DATA COLLECTION AND ANALYSIS

We extracted data from eligible studies for the primary outcomes of stroke recurrence and vascular death, and secondary outcomes of myocardial infarction; composite outcome of stroke, myocardial infarction, and vascular death; intracranial haemorrhage; extracranial haemorrhage; ischaemic stroke; death from all causes; and haemorrhagic stroke. We computed an estimate of treatment effect and performed a test for heterogeneity between trials. We analysed data on an intention-to-treat basis and assessed bias for all studies. We rated the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 15 RCTs with a total of 17,091 participants. Compared with fewer antiplatelet agents, multiple antiplatelet agents were associated with a significantly lower risk of stroke recurrence (5.78% versus 7.84%, risk ratio (RR) 0.73, 95% confidence interval (CI) 0.66 to 0.82; P < 0.001; moderate-certainty evidence) with no significant difference in vascular death (0.60% versus 0.66%, RR 0.98, 95% CI 0.66 to 1.45; P = 0.94; moderate-certainty evidence). There was a higher risk of intracranial haemorrhage (0.42% versus 0.21%, RR 1.92, 95% CI 1.05 to 3.50; P = 0.03; low-certainty evidence) and extracranial haemorrhage (6.38% versus 2.81%, RR 2.25, 95% CI 1.88 to 2.70; P < 0.001; high-certainty evidence) with multiple antiplatelet agents. On secondary analysis of dual versus single antiplatelet agent therapy, benefit for stroke recurrence (5.73% versus 8.06%, RR 0.71, 95% CI 0.62 to 0.80; P < 0.001; moderate-certainty evidence) was maintained as well as risk of extracranial haemorrhage (1.24% versus 0.40%, RR 3.08, 95% CI 1.74 to 5.46; P < 0.001; high-certainty evidence). The composite outcome of stroke, myocardial infarction, and vascular death (6.37% versus 8.77%, RR 0.72, 95% CI 0.64 to 0.82; P < 0.001; moderate-certainty evidence) and ischaemic stroke (6.30% versus 8.94%, RR 0.70, 95% CI 0.61 to 0.81; P < 0.001; high-certainty evidence) were significantly in favour of dual antiplatelet therapy, whilst the risk of intracranial haemorrhage became less significant (0.34% versus 0.21%, RR 1.53, 95% CI 0.76 to 3.06; P = 0.23; low-certainty evidence).

AUTHORS' CONCLUSIONS

Multiple antiplatelet agents are more effective in reducing stroke recurrence but increase the risk of haemorrhage compared to one antiplatelet agent. The benefit in reduction of stroke recurrence seems to outweigh the harm for dual antiplatelet agents initiated in the acute setting and continued for one month. There is lack of evidence regarding multiple versus multiple antiplatelet agents. Further studies are required in different populations to establish comprehensive safety profiles and long-term outcomes to establish duration of therapy.

Short- vs. long-term dual antiplatelet therapy in secondary prevention for ischaemic stroke: a network metanalysis

AIMS

This review aimed to compare the efficacy and safety of short-term (≤3 months) and long-term (≥1 year) dual-antiplatelet therapy (DAPT) in secondary prevention for ischaemic stroke.

METHODS AND RESULTS

We searched MEDLINE, EMBASE (Ovid), PubMed, Cochrane Library, ClinicalTrials.gov, and Google Advanced Search for randomized controlled trials. The population consisted of patients with recent ischaemic stroke or transient ischaemic attack. The intervention was DAPT with a combination of aspirin, clopidogrel, and dipyridamole compared to either aspirin or clopidogrel in monotherapy. The primary outcome was the rate of all recurrent stroke (ischaemic and haemorrhagic). Secondary outcomes were ischaemic stroke, all bleeding, severe bleeding, all-cause death, cardiovascular death, and myocardial infarction. Data were pooled by network metanalysis and pairwise metanalyses. Sixteen studies with 55 261 participants were included. Compared to aspirin, DAPT with aspirin clopidogrel decreased the risk of recurrent stroke [short-term odds ratio (OR) 0.67, 95% confidence interval (CI) 0.58-0.77; long-term OR 0.84, 95% CI 0.70-1.01] at the expense of increased risk of bleeding (short-term OR 1.76, 95% CI 1.26-2.46; long-term OR 2.25, 95% CI 1.97-2.57). Dual antiplatelet therapy with aspirin clopidogrel and clopidogrel in monotherapy had similar long-term risk of recurrent stroke (OR 0.98, 95% CI 0.83-1.14), but DAPT was associated with increased risk of bleeding (OR 2.77, 95% CI 2.21-3.46). Network metanalysis showed that short-term aspirin clopidogrel DAPT had the best risk-benefit profile, followed by long-term aspirin clopidogrel DAPT and clopidogrel alone. Aspirin dipyridamole DAPT was less effective.

CONCLUSION

Short-term DAPT had better risk-benefit profile than long-term DAPT.

Treatment Approaches to Lacunar Stroke

Lacunar strokes are appropriately named for their ability to cavitate and form ponds or "little lakes" (Latin: lacune -ae meaning pond or pit is a diminutive form of lacus meaning lake). They account for a substantial proportion of both symptomatic and asymptomatic ischemic strokes. In recent years, there have been several advances in the management of large vessel occlusions. New therapies such as non-vitamin K antagonist oral anticoagulants and left atrial appendage closure have recently been developed to improve stroke prevention in atrial fibrillation; however, the treatment of small vessel disease-related strokes lags frustratingly behind. Since Fisher characterized the lacunar syndromes and associated infarcts in the late 1960s, there have been no therapies specifically targeting lacunar stroke. Unfortunately, many therapeutic agents used for the treatment of ischemic stroke in general offer only a modest benefit in reducing recurrent stroke while adding to the risk of intracerebral hemorrhage and systemic bleeding. Escalation of antithrombotic treatments beyond standard single antiplatelet agents has not been effective in long-term lacunar stroke prevention efforts, unequivocally increasing intracerebral hemorrhage risk without providing a significant benefit. In this review, we critically review the available treatments for lacunar stroke based on evidence from clinical trials. For several of the major drugs, we summarize the adverse effects in the context of this unique patient population. We also discuss the role of neuroprotective therapies and neural repair strategies as they may relate to recovery from lacunar stroke.

Use of oral anticoagulant drugs is associated with carotid intraplaque hemorrhage in atherosclerosis patients: a meta-analysis

Patients with carotid atherosclerosis, especially the elderly population, take antithrombotic medicine regularly. However, no previous meta-analysis has focused on one of the possible side effects of such drugs, namely intraplaque hemorrhage (IPH). To determine whether antiplatelet drugs or anticoagulants are associated with an increased risk of carotid IPH. We searched Pubmed, Embase, Ovid MEDLINE, Cochrane Library for relevant studies that were published in English, from January 1st, 1989 to January 1st, 2019. We pooled the odds ratio (OR) with 95% confidence interval (CI) from individual studies and conducted quality assessment, heterogeneity, publication bias analysis and sensitivity analysis. A total of four cross-sectional studies, involving 2714 participants with carotid atherosclerotic plaques was included into this meta-analysis. We found a significant association between the use of anticoagulants and higher risk of carotid IPH (OR 1.95; 95% CI 1.16-3.30, P = 0.92; I2 = 0). No significant association was found between the use of antiplatelet drugs and increased risk of carotid IPH (OR 1.34; 95% CI 0.68-2.61, P = 0.03; I2 = 65%). Our meta-analysis reveals that it is the use of oral anticoagulants rather than antiplatelet drugs that may be associated with an increased risk of carotid IPH in atherosclerosis patients.

Comparative efficacy and safety of antiplatelet agents in cerebral ischemic disease: A network meta-analysis

We performed a network meta-analysis (NMA) to enhance the corresponding evidence of the relative efficacy and safety of different antiplatelet agents in cerebral ischemic disease. PubMed and EMBASE were searched systematically for relevant studies. Outcomes were compared using odds ratios and 95% credible intervals. Each agent was ranked according to the value of surface under the cumulative ranking curve (SUCRA). Publication bias was evaluated by funnel plots, while consistency between direct and indirect comparison was analyzed by node-splitting and heat plots. Besides, the clustering technique was used to categorize similar agents. A number of 44 eligible studies with 148 578 patients were included in this NMA. In terms of efficacy (including mortality, recurrent stroke, and vascular event), all six interventions were better than placebo. clopidogrel (Clop) and aspirin (ASA)+Clop were the best two interventions from SUCRA. However, the performance of ASA+Clop declined significantly when considering safety (including myocardial infarction, all-cause withdrawal, and intracranial hemorrhage), especially worse in intracranial hemorrhage. In conclusion, Clop was potentially the most preferable treatment for preventing cerebral ischemic in terms of efficacy and safety. However, the addition of ASA was associated with a potential increase in intracranial hemorrhage, therefore, combination therapy of ASA and Clop should be introduced with caution although it may be more effective than the monotherapy of ASA.

Use of Antiplatelet Agents in the Neurosurgical Patient

Antiplatelet agents used to treat neurovascular disease include aspirin; P2Y12 receptor antagonists clopidogrel, prasugrel, and ticagrelor; ADP antagonist ticlopidine; phosphodiesterase inhibitor dipyridamole; and glycoprotein IIb/IIIa inhibitors abciximab, eptifibatide, and tirofiban. Numerous studies have been performed evaluating their efficacy in stroke, extracranial carotid artery disease and dissection, intracranial atherosclerotic disease, and moyamoya disease. The rapid technological advancements in endovascular neurosurgical devices have also made antiplatelet therapy a necessary part of treating intracranial aneurysms. This article presents the relevant data supporting the use of antiplatelet agents in vascular neurosurgery and recommendations based on the described studies.

Effect of Antiplatelet Therapy (Aspirin + Dipyridamole Versus Clopidogrel) on Mortality Outcome in Ischemic Stroke

The optimal regimen of antiplatelet therapy for secondary prevention in noncardioembolic ischemic stroke remains controversial. We aimed to determine which regimen was associated with the greatest reduction in adverse outcomes. We analysed prospectively collected data from the Norfolk and Norwich University Hospital Stroke Register. The sample population consisted of 3,572 participants (mean age 74.96 ± 12.67) with ischemic stroke, who were consecutively admitted between 2003 and 2015. Patients were placed on one of three antiplatelet regimens at hospital discharge; aspirin monotherapy, aspirin plus dipyridamole and clopidogrel. Clopidogrel and aspirin plus dipyridamole were compared to aspirin. A direct comparison between clopidogrel and aspirin plus dipyridamole was also performed. Outcomes included all-cause mortality and a combined end point of all-cause mortality and incidence of major adverse cardiac events (stroke or myocardial infarction). Cox-regression models adjusted for potential confounders at the following time periods after discharge; 0 to 90 days, 91 to 365 days, and 1 to 3 years. Aspirin plus dipyridamole was associated with a lower risk of mortality at 0 to 90 days; hazard ratio (HR) 0.62 (0.43 to 0.91). Clopidogrel was associated with a lower risk of mortality at 1 to 3 years; HR of 0.39 (0.26 to 0.60). Similar HRs were observed for the corresponding time points in the composite outcome. In conclusion, patients with noncardioembolic stroke may gain maximum benefits from aspirin plus dipyridamole initially (≤1 year) with a subsequent switch to clopidogrel, with regard to mortality and major adverse cardiac eventsoutcomes.

Peripheral interventions and antiplatelet therapy: Role in current practice

Peripheral arterial disease (PAD) is a common disorder associated with a high risk of cardiovascular mortality and continues to be under-recognized. The major risk factors for PAD are similar to those for coronary and cerebrovascular disease. Management includes exercise program, pharmacologic therapy and revascularization including endovascular and surgical approach. The optimal revascularization strategy, endovascular or surgical intervention, is often debated due to the paucity of head to head randomized controlled studies. Despite significant advances in endovascular interventions resulting in increased utilization over surgical bypass, significant challenges still remain. Platelet activation and aggregation after percutaneous transluminal angioplasty of atherosclerotic arteries are important risk factors for re-occlusion/restenosis and life-threatening thrombosis following endovascular procedures. Antiplatelet agents are commonly prescribed to reduce the risk of myocardial infarction, stroke and death from cardiovascular causes in patients with PAD. Despite an abundance of data demonstrating efficacy of antiplatelet therapy in coronary artery disease and cerebrovascular disease, there is a paucity of clinical information, clinical guidelines and randomized controlled studies in the PAD population. Hence, data on antiplatelet therapy in coronary interventions is frequently extrapolated to peripheral interventions. The aim of this review article is to elucidate the current data on revascularization and the role and duration of antiplatelet and anticoagulant therapy in re-vascularized lower limb PAD patients.

The Efficacy and Safety of 3 Types of Interventions for Stroke Prevention in Patients With Cardiovascular and Cerebrovascular Diseases: A Network Meta-analysis

PURPOSE

The goal of this study was to compare the relative efficacy and safety of different types of interventions for stroke prevention in patients with cardiovascular and cerebrovascular diseases.

METHODS

This network meta-analysis (NMA) was conducted with a random effects model of Bayesian framework using Stata version 12.0. Odds ratios (ORs) and their credible intervals (CrIs) were applied for the efficacy and safety evaluation of various medical interventions, including aspirin, dipyridamole, ticlopidine, warfarin, and apixaban. In addition, the ranking of probability of every clinical outcome was estimated by comparing the surface under the cumulative ranking curve.

FINDINGS

Compared with dabigatran, both edoxaban and aspirin + warfarin exhibited a higher rate of all-cause stroke (OR, 2.84 [95% CrI, 1.17-6.97]; OR, 3.42 [95% CrI, 1.20-9.84]). With respect to intracranial hemorrhage, aspirin + clopidogrel yielded worse outcomes than 7 treatments, including placebo, apixaban, aspirin, aspirin + dipyridamole, cilostazol, clopidogrel, and dabigatran (OR, 2.21 [95% CrI, 1.45-3.40]; OR, 2.11 [95% CrI, 1.05-4.17]; OR, 1.53 [95% CrI, 1.11-2.15]; OR, 1.78 [95% CrI, 1.01-3.03]; OR, 4.17 [95% CrI, 1.37-14.28]; OR, 1.85 [95% CrI, 1.22-2.86]; and OR, 2.56 [95% CrI, 1.37-4.76]). In terms of ischemic stroke, dabigatran provided better efficacy than placebo, aspirin, and aspirin + dipyridamole (OR, 0.36 [95% CrI, 0.18-0.72]; OR, 0.43 [95% CrI, 0.21-0.84]; and OR, 0.41 [95% CrI, 0.17-0.94]). As for mortality, dabigatran resulted in a lower mortality compared with aspirin, aspirin + clopidogrel, edoxaban, and warfarin (OR, 0.48 [95% CrI, 0.23-0.97]; OR, 0.40 [95% CrI, 0.17-0.92]; OR, 0.27 [95% CrI, 0.10-0.72]; and OR, 0.52 [95% CrI, 0.28-0.92]).

IMPLICATIONS

There are still some limitations to our NMA research. For instance, the lack of direct evidence for some therapies resulted in inconsistencies, particularly for warfarin compared with placebo and clopidogrel under different end points. Moreover, the included randomized controlled trials for patients with cardiovascular and cerebrovascular diseases are relatively broad, involving atrial fibrillation, myocardial infarction, and large-artery atherosclerosis stroke. Although further research is needed, dabigatran is highly recommended based on the present NAM for the treatment of cardiovascular and cerebrovascular diseases due to the drug's efficacy and safety.

Secondary Stroke Prevention with Antiplatelet Drugs: Have We Reached the Ceiling?

Patients with transient ischemic attack (TIA) or ischemic stroke carry a risk of recurrent stroke of between 5% and 20% per year. In patients with TIA or ischemic stroke of non-cardiac origin, antiplatelet drugs are able to decrease the relative risk of stroke by 11–15% and the risk of stroke, myocardial infarction, and vascular death by 15–22%. Aspirin is the most widely used drug. It is affordable and effective. Low doses of 50–325 mg aspirin are as effective as high doses and cause less gastrointestinal side-effects. The combination of aspirin with slow-release dipyridamole is superior to aspirin alone for stroke prevention but not for the prevention of cardiac events. The risk of major bleeding complications is not increased with the combination, which suggests that dipyridamole might act in another way than as antiplatelet drug. Clopidogrel is not superior to aspirin in unselected stroke patients but is superior in patients at high risk of recurrence. The combination of aspirin plus clopidogrel is not more effective than clopidogrel alone, but carries a higher bleeding risk. The most effective antiplatelet drugs, the GP IIb/IIIa antagonists, are not superior to aspirin and carry a higher risk of bleeding. These results indicate that any antiplatelet therapy with a more potent drug than aspirin will only have a marginally higher efficacy, which might be offset by a higher bleeding rate. Therefore, selection of patients who might benefit from antiplatelet therapy other than aspirin is important.

Antiplatelet Agents for the Secondary Prevention of Ischemic Stroke or Transient Ischemic Attack: A Network Meta-Analysis

Stroke can cause high morbidity and mortality, and ischemic stroke (IS) and transient ischemic attack (TIA) patients have a high stroke recurrence rate. Antiplatelet agents are the standard therapy for these patients, but it is often difficult for clinicians to select the best therapy from among the multiple treatment options. We therefore performed a network meta-analysis to estimate the efficacy of antiplatelet agents for secondary prevention of recurrent stroke. We systematically searched 3 databases (PubMed, Embase, and Cochrane) for relevant studies published through August 2015. The primary end points of this meta-analysis were overall stroke, hemorrhagic stroke, and fatal stroke. A total of 30 trials were included in our network meta-analysis and abstracted data. Among the therapies evaluated in the included trials, the estimates for overall stroke and hemorrhagic stroke for cilostazol (Cilo) were significantly better than those for aspirin (odds ratio [OR] = .64, 95% credibility interval [CrI], .45-.91; OR = .23, 95% CrI, .08-.58). The estimate for fatal stroke was highest for Cilo plus aspirin combination therapy, followed by Cilo therapy. The results of our meta-analysis indicate that Cilo significantly improves overall stroke and hemorrhagic stroke in IS or TIA patients and reduces fatal stroke, but with low statistical significance. Our results also show that Cilo was significantly more efficient than other therapies in Asian patients; therefore, future trials should focus on Cilo treatment for secondary prevention of recurrent stroke in non-Asian patients.

Antiplatelet regimens in the long-term secondary prevention of transient ischaemic attack and ischaemic stroke: an updated network meta-analysis

OBJECTIVE

To examine the comparative efficacy and safety of different antiplatelet regimens in patients with prior non-cardioembolic ischaemic stroke or transient ischaemic attack.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

As on 31 March 2015, all randomised controlled trials that investigated the effects of antiplatelet agents in the long-term (≥ 3 months) secondary prevention of non-cardioembolic transient ischaemic attack or ischaemic stroke were searched and identified.

OUTCOME MEASURES

The primary outcome measure of efficacy was serious vascular events (non-fatal stroke, non-fatal myocardial infarction and vascular death). The outcome measure of safety was any bleeding.

RESULTS

A total of 36 randomised controlled trials (82,144 patients) were included. Network meta-analysis showed that cilostazol was significantly more effective than clopidogrel (OR 0.77, 95% credible interval 0.60-0.98) and low-dose (75-162 mg daily) aspirin (0.69, 0.55-0.86) in the prevention of serious vascular events. Aspirin (50 mg daily) plus dipyridamole (400 mg daily) and clopidogrel reduced the risk of serious vascular events compared with low-dose aspirin; however, the difference was not statistically significant. Furthermore, low-dose aspirin was as effective as higher daily doses. Cilostazol was associated with a significantly lower bleeding risk than most of the other regimens. Moreover, aspirin plus clopidogrel was associated with significantly more haemorrhagic events than other regimens. Direct comparisons showed similar results as the network meta-analysis.

CONCLUSIONS

Cilostazol was significantly more effective than aspirin and clopidogrel alone in the long-term prevention of serious vascular events in patients with prior non-cardioembolic ischaemic stroke or transient ischaemic attack. Cilostazol was associated with a significantly lower bleeding risk than low-dose aspirin (75-162 mg daily) and aspirin (50 mg daily) plus dipyridamole (400 mg daily). Low-dose aspirin was as effective as higher daily doses. However, further large, randomised, controlled, head-to-head trials are needed, especially in non-Asian ethnic groups.

Comparative Efficacy and Safety of Nine Anti-Platelet Therapies for Patients with Ischemic Stroke or Transient Ischemic Attack: a Mixed Treatment Comparisons

Anti-platelet treatments, an effective anti-thrombotic therapy, are widely used in non-cardioembolic ischemic stroke or transient ischemic attack (TIA), including aspirin, cilostazol, clopidogrel, and other mono or dual therapies, while the optimal choice remains uncertain. All the literatures of 38 eligible randomized control trials were searched in PubMed, Embase, and China National Knowledge Internet (CNKI) without language limitation. And, nine anti-platelet therapies were assessed, including aspirin, clopidogrel, cilostazol, ticlopidine, triflusal, terutroban, sarpogrelate, dipyridamole plus aspirin, and clopidogrel plus aspirin. Additionally, we extract data of composite vascular events, major bleeding, ischemic stroke, intracranial hemorrhage, and all-cause death, as indicators of efficacy and safety. And among them, composite vascular events were the primary outcome. The binary outcomes were expressed as odds ratios (ORs) with corresponding 95 % confidence intervals (CIs). Both traditional meta-analysis and network meta-analysis were performed. Besides, for each outcome, the rank order was applied to reflect the superiority of every therapy compared with others, using the surface under the cumulative ranking curve (SUCRA). A cluster analysis was also conducted. Through the network meta-analysis, the synthesized data shows that cilostazol performed best on composite vascular events compared with placebo (OR = 0.62, 95 % CI 0.46-0.83) and aspirin (OR = 0.71, 95 % CI 0.53-0.95). In terms of ischemic stroke, clopidogrel plus aspirin seems the optimal, and it has significant difference between placebo (OR = 0.53, 95 % CI 0.35-0.74) and aspirin (OR = 0.75, 95 % CI 0.61-0.95). Meanwhile, cilostazol is also the first rank in major bleeding, especially when it is in contrast to aspirin (OR = 0.13, 95 % CI 0.02-0.70) and clopidogrel plus aspirin (OR = 0.09, 95 % CI 0.01-0.50). There is no significant difference among these nine treatments and placebo, as to all-cause death and intracranial hemorrhage. According to the cluster analysis, cilostazol can be the best choice with comprehensive assessment of composite vascular events, ischemic stroke and major bleeding. Based on this network meta-analysis, cilostazol was recommended as the optimal choice with good performance in both efficacy and safety for patient with ischemic stroke or TIA among nine anti-platelet therapies.

Long-Term Antiplatelet Mono- and Dual Therapies After Ischemic Stroke or Transient Ischemic Attack: Network Meta-Analysis

BACKGROUND

The latest guidelines do not make clear recommendations on the selection of antiplatelet therapies for long-term secondary prevention of stroke. We aimed to integrate the available evidence to create hierarchies of the comparative efficacy and safety of long-term antiplatelet therapies after ischemic stroke or transient ischemic attack.

METHODS AND RESULTS

We performed a network meta-analysis of randomized controlled trials to compare 11 antiplatelet therapies in patients with ischemic stroke or transient ischemic attack. In December 2014, we searched Medline, Embase, and the Cochrane Library database for trials. The search identified 24 randomized controlled trials including a total of 85 667 patients with antiplatelet treatments for at least 1 year. Cilostazol significantly reduced stroke recurrence in comparison with aspirin (odds ratio 0.66, 95% credible interval 0.44 to 0.92) and dipyridamole (odds ratio 0.57, 95% credible interval 0.34 to 0.95), respectively. Cilostazol also significantly reduced intracranial hemorrhage compared with aspirin, clopidogrel, terutroban, ticlopidine, aspirin plus clopidogrel, and aspirin plus dipyridamole. Aspirin plus clopidogrel could not significantly reduce stroke recurrence compared with monotherapies but caused significantly more major bleeding than all monotherapies except terutroban. The pooled estimates did not change materially in the sensitivity analyses of the primary efficacy outcome.

CONCLUSIONS

Long-term monotherapy was a better choice than long-term dual therapy, and cilostazol had the best risk-benefit profile for long-term secondary prevention after stroke or transient ischemic attack. More randomized controlled trials in non-East Asian patients are needed to determine whether long-term use of cilostazol is the best option for the prevention of recurrent stroke.

Secondary stroke prevention: challenges and solutions

Stroke is the leading cause of disability in the USA and a major cause of mortality worldwide. One out of four strokes is recurrent. Secondary stroke prevention starts with deciphering the most likely stroke mechanism. In general, one of the main goals in stroke reduction is to control vascular risk factors such as hypertension, diabetes, dyslipidemia, and smoking cessation. Changes in lifestyle like a healthy diet and aerobic exercise are also recommended strategies. In the case of cardioembolism due to atrial fibrillation, mechanical valves, or cardiac thrombus, anticoagulation is the mainstay of therapy. The role of anticoagulation is less evident in the case of bioprosthetic valves, patent foramen ovale, and dilated cardiomyopathy with low ejection fraction. Strokes due to larger artery atherosclerosis account for approximately a third of all strokes. In the case of symptomatic extracranial carotid stenosis, surgical intervention as close as possible in time to the index event seems highly beneficial. In the case of intracranial large artery atherosclerosis, the best medical therapy consists of antiplatelets, high-dose statins, aggressive controls of vascular risk factors, and lifestyle modifications, with no role for intracranial arterial stenting or angioplasty. For patients with small artery occlusion (ie, lacunar stroke), the therapy is similar to that used in patients with intracranial large artery atherosclerosis. Despite the constant new evidence on how to best treat patients who have suffered a stroke, the risk of stroke recurrence remains unacceptably high, thus evidencing the need for novel therapies.

Antiplatelet strategies for secondary prevention of stroke and TIA

Stroke is a major public health issue, and stroke recurrence accounts for a quarter of all events. Antiplatelet therapy has been extensively studied for secondary stroke prevention and is established as effective in this high-risk population. Several agents have been evaluated in this setting, both in isolation and combination. The most widely used antiplatelet medications are aspirin, clopidogrel, and aspirin plus extended-release dipyridamole. However, new agents and combinations continue to be evaluated. A detailed review of the evidence supporting various antiplatelet regimens for secondary stroke prevention is outlined with special focus on recent developments that may impact clinical management of patients with stroke or TIA.

Prevention and Management of Cerebral Small Vessel Disease

Lacunar infarcts/lacunes, white matter hyperintensities (WMH), and cerebral microbleeds (CMBs) are considered various manifestations of cerebral small vessel disease (SVD). Since the exact mechanisms of these manifestations differ, their associated risk factors differ. High blood pressure is the most consistent risk factor for all of these manifestations. However, a "J curve" phenomenon in terms of blood pressure probably exists for WMH. The association between cholesterol levels and lacunar infarcts/lacunes or WMH was less consistent and sometimes conflicting; a low cholesterol level probably increases the risk of CMBs. Homocysteinemia appears to be associated with WMH. It is noteworthy that the risk factors profile may also differ between different lacunar patterns and CMBs located at different parts of the brain. Thrombolysis, antihypertensives, and statins are used to treat patients with symptomatic lacunar infarction, just as in those with other stroke subtypes. However, it should be remembered that bleeding risks increase in patients with extensive WMH and CMBs after thrombolysis therapy. According to the Secondary Prevention of Small Subcortical Strokes trial results, a blood pressure reduction to <130 mmHg is recommended in patients with symptomatic lacunar infarction. However, an excessive blood pressure decrease may induce cognitive decline in older patients with extensive WMH. Dual antiplatelet therapy (aspirin plus clopidogrel) should be avoided because of the excessive risk of intracerebral hemorrhage. Although no particular antiplatelet is recommended, drugs such as cilostazol or triflusal may have advantages for patients with SVD since they are associated with less frequent bleeding complications than aspirin.

Efficacy of antiplatelet therapy in secondary prevention following lacunar stroke: pooled analysis of randomized trials

BACKGROUND AND PURPOSE

Lacunar stroke accounts for ≈25% of ischemic stroke, but optimal antiplatelet regimen to prevent stroke recurrence remains unclear. We aimed to evaluate the efficacy of antiplatelet agents in secondary stroke prevention after a lacunar stroke.

METHODS

We searched MEDLINE, Embase, and the Cochrane library for randomized controlled trials that reported risk of recurrent stroke or death with antiplatelet therapy in patients with lacunar stroke. We used random effects meta-analysis and evaluated heterogeneity with I(2).

RESULTS

We included 17 trials with 42,234 participants (mean age 64.4 years, 65% male) and follow up ranging from 4 weeks to 3.5 years. Compared with placebo, any single antiplatelet agent was associated with a significant reduction in recurrence of any stroke (risk ratio [RR] 0.77, 0.62-0.97, 2 studies) and ischemic stroke (RR 0.48, 0.30-0.78, 2 studies), but not for the composite outcome of any stroke, myocardial infarction, or death (RR 0.89, 0.75-1.05, 2 studies). When other antiplatelet agents (ticlodipine, cilostazol, and dipyridamole) were compared with aspirin, there was no consistent reduction in stroke recurrence (RR 0.91, 0.75-1.10, 3 studies). Dual antiplatelet therapy did not confer clear benefit over monotherapy (any stroke RR 0.83, 0.68-1.00, 3 studies; ischemic stroke RR 0.80, 0.62-1.02, 3 studies; composite outcome RR 0.90, 0.80-1.02, 3 studies).

CONCLUSIONS

Our results suggest that any of the single antiplatelet agents compared with placebo in the included trials is adequate for secondary stroke prevention after lacunar stroke. Dual antiplatelet therapy should not be used for long-term stroke prevention in this stroke subtype.

Total burden of intraplaque hemorrhage in coronary arteries relates to the use of coumarin-type anticoagulants but not platelet aggregation inhibitors

Intraplaque hemorrhage (IPH) is a crucial factor in progression and destabilization of an atherosclerotic plaque. Anti-thromboembolic drugs are widely used as prophylactic treatment against arterial and venous thrombotic diseases, but a major complication is bleeding. We investigated the association between exposure to anti-thromboembolic therapy and IPH in postmortem coronary arteries. Coronary arteries with postmortem angiographically confirmed extensive atherosclerosis were obtained at autopsy from patients who had received oral anticoagulants (n = 10), platelet aggregation inhibitors (n = 10), or no anti-thrombotic drugs (n = 10) before death. Coronary arteries were cut at 3-mm interval, and all plaque-containing segments were immunohistochemically screened for IPH and microvessels. These data were related to overall plaque composition and the use of anti-thromboembolic therapies. IPH was found in 483 out of 904 (53 %) coronary segments with advanced atherosclerotic plaques and more frequently in patients on oral anticoagulants (174/284, 61 %) than in patients on anti-platelets (198/376, 53 %) or without therapy (111/244, 46 %) (P = 0.02 and P = 0.001, respectively). Also, intraplaque microvascular leakage was more frequently observed in patients on anticoagulants than in non-treated patients (P = 0.03). Finally, the IPH appeared to be larger in plaques of patients on anticoagulant treatment (P < 0.001). Density of intraplaque microvessels was highest in plaques of patients on platelet inhibitors (P < 0.05), but this was not associated with increased hemorrhagic burden. Prophylactic therapy with oral coumarin-type anticoagulants appears to be associated with a higher hemorrhagic burden in atherosclerotic coronary arteries, which may lead to increase in plaque volume over time, in this selected subgroup of patients.

Dual antiplatelet therapy after noncardioembolic ischemic stroke or transient ischemic attack: pros and cons

Dual antiplatelet therapy simultaneously blocks different platelet activation pathways and might thus be more potent at inhibiting platelet activation and more effective at reducing major ischemic vascular events compared to antiplatelet monotherapy. Aspirin plus clopidogrel dual therapy is now the standard therapy for patients with acute coronary syndrome and for those undergoing percutaneous coronary intervention. However, dual antiplatelet therapy carries an increased risk of bleeding. Patients with ischemic stroke or transient ischemic attack (TIA) are generally older and likely to have a fragile cerebrovascular bed, which further increases the risk of systemic major bleeding events and intracranial hemorrhage. Clinical trials and meta-analyses suggest that in comparison to antiplatelet monotherapy, dual antiplatelet therapy initiated early after noncardioembolic ischemic stroke or TIA further reduces the rate of recurrent stroke and major vascular events without significantly increasing the rate of major bleeding events. In contrast, studies of long-term therapy in patients with noncardioembolic ischemic stroke or TIA have yielded inconsistent data regarding the benefit of dual antiplatelet therapy over monotherapy. However, the harm associated with major bleeding events, including intracranial hemorrhage, which is generally more disabling and more fatal than ischemic stroke, is likely to increase with dual antiplatelet therapy. Physicians should carefully assess the benefits and risks of dual antiplatelet therapy versus antiplatelet monotherapy when managing patients with ischemic stroke or TIA.

Advancements in understanding the mechanisms of symptomatic lacunar ischemic stroke: translation of knowledge to prevention strategies

Symptomatic lacunar ischemic stroke (25% of all brain infarctions) results from occlusion of a single penetrating artery by microatheromas or lipohyalinosis and rarely from an intracranial atheromatous branch disease. Recurrent lacunar stroke may be associated with more severe clinical features and has been involved in producing lacunar state and vascular subcortical dementia. In the first multicenter randomized clinical trial (SPS3) focused on stroke prevention among patients with recent lacunar stroke, the addition of clopidogrel to aspirin not only did not reduced significantly the risk of recurrent stroke, but also increased significantly the likelihood of hemorrhage and fatal outcome. If lacunar stroke is primarily non-atherothromboembolic, secondary prevention aimed at preventing atheroma progression may not be very effective. The efficacy of drugs that improve endothelial function in lacunar stroke patients remains to be studied in the future.

European Stroke Prevention Study 2: A study of low-dose acetylsalicylic acid and of high dose dipyridamole in secondary prevention of cerebro-vascular accidents

In spite of some data being added to our knowledge of the effect of antiplatelets in secondary prevention of brain ischemic lesion in recent years, the main reasons to perform a second European Stroke Prevention Study (ESPS 2), which started in 1987-1988, were: (a) clarify the relative roles of aspirin (ASA) and dipyridamole (DP) alone or in combination; (b) confirm the efficacy of small doses of ASA and, so doing, decrease the number of drop-outs due to ASA side effects; (c) join information to the effect of antiplatelets in complete stroke. General characteristics of the sample of 6602 patients are presented and compared with other major trials and series. The patients in the four treatment arms (aspirin, dipyridamole, aspirin + dipyridamole and placebo) are compared. The more relevant features and risk factors known to influence long term prognosis are described and discussed. The small proportion of patients included with TIA (23.7%) and the comparability among treatment groups are stressed. No relevant differences have been found, among groups, on the sex or age distribution, prevalence of hypertension, diabetes, previous vascular events or atrial fibrillation, nor in the characteristics of the accident leading to the inclusion in trial.

Unique experiences with intercontinental trials in stroke - part II

Supported by the Canadian Medical Research Council we performed a randomized trial extending from Newfoundland to British Columbia. With others a number of observations showed that aspirin will reduce stroke. With National Institute of Neurological Disorders and Stroke support we learned who would benefit and not from surgery in these stroke threatened carotid diseased patients. We evaluated the upper limits of acceptability of complications beyond which harm was done. Amassing this large data base of approximately 5000 individuals, followed for five years, previously unknown carotid phenomena were observed: 1. Ischemic stroke occurs in patients with prolapsing mitral valves; 2. There is risk of stroke in patients with residual thrombi in the occluded stump of the carotid artery; 3. We detected a lower risk than expected in patients with nearly occluded carotid arteries. We support the contention of Yusuf and Cairns' that Canada needs to give more financial support to purely clinical research. It pays off !

Aspirin and clopidogrel for prevention of ischemic stroke

This review examines the role of platelets in ischemic stroke, platelet activation mechanisms, aspirin's rise as an antithrombotic agent, clopidogrel's appearance on the stage, a possible role for combination therapy, antiplatelet resistance, practical considerations, and future directions. Reviewed in this chapter are issues central to optimal antiplatelet therapy: efficacy, safety, resistance, and biochemical/laboratory testing. Current guidelines do not recommend combination aspirin and clopidogrel use, however recent research indicates dual antiplatelet therapy with combined aspirin and clopidogrel may have specific roles in secondary prevention of ischemic stroke. A cautious and analytical interpretation of the literature is advised before application of this knowledge to clinical practice. The best recommendation at this time is to follow the published guidelines for secondary prevention of ischemic stroke.

Plasminogen activators and ischemic stroke: conditions for acute delivery

Appropriate acute treatment with plasminogen activators (PAs) can significantly increase the probability of minimal or no disability in selected ischemic stroke patients. There is a great deal of evidence showing that intravenous recombinant tissue PAs (rt-PA) infusion accomplishes this goal, recanalization with other PAs has also been demonstrated in the development of this treatment. Recanalization of symptomatic, documented carotid or vertebrobasilar arterial territory occlusions have also been achieved by local intra-arterial PA delivery, although only a single prospective double-blinded randomized placebo-controlled study has been reported. The increase in intracerebral hemorrhage with these agents by either delivery approach underscores the need for careful patient selection, dose-appropriate safety and efficacy, proper clinical trial design, and an understanding of the evolution of cerebral tissue injury due to focal ischemia. Principles underlying the evolution of focal ischemia have been expanded by experience with acute PA intervention. Several questions remain open that concern the manner in which PAs can be applied acutely in ischemic stroke and how injury development can be limited.

Genetic dissection of platelet function in health and disease using systems biology

Technological advances in protein and genetic analysis have altered the means by which platelet disorders can be characterized and studied in health and disease. When integrated into a single analytical framework, these collective technologies are referred to as systems biology, a unified approach that links platelet function with genomic/proteomic studies to provide insight into the role of platelets in broad human disorders such as cardiovascular and cerebrovascular disease. This article reviews the historical progression of these applied technologies to analyze platelet function, and demonstrates how these approaches can be systematically developed to provide new insights into platelet biomarker discovery.

Platelet systems biology using integrated genetic and proteomic platforms

Platelets retain megakaryocyte-derived mRNA, an abundant and diverse array of miRNAs, and have evolved unique adaptive signals for maintenance of genetic and protein diversity. Quiescent platelets generally display minimal translational activity, although maximally-activated platelets retain the capacity for protein synthesis. Progressive data using multiple platelet activation models clearly demonstrate that platelet responses to the majority (if not all) agonists are highly variable within the population, demonstrating considerable heritability in siblings, twins, and families with premature coronary artery disease. Research from our laboratory has adapted global profiling strategies to close the knowledge gap currently existing between genetic variability and platelet phenotypic responsiveness. We have applied iterative algorithms for genetic biomarker discovery and class prediction models of platelet phenotypes, with the goal of systematically analyzing integrated mRNA/miRNA/proteomic datasets for identification of regulatory networks that define phenotypic variability in platelet responses. This approach has the potential to define platelet genetic biomarkers predictive of thrombohemorrhagic outcomes in both normal and widely disparate clinical conditions.