Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial

The pharmacology of antiplatelet agents for primary, secondary, and tertiary prevention of ischemic stroke

INTRODUCTION

Ischemic etiology accounts for two thirds of all strokes in which platelet activation and aggregation play a major role. A variety of antiplatelet therapies have been tested for primary, secondary, and tertiary prevention, with certain patient subtypes benefiting more than others from a specific regimen.

AREAS COVERED

This review aims at synthetizing current evidence on pharmacology of antiplatelet agents approved for primary, secondary, and tertiary stroke prevention and their application among possible patient subtypes that may benefit more from their administration.

EXPERT OPINION

Management of ischemic stroke has largely evolved over the past decades. A better understanding of stroke pathophysiology has allowed to identify patients who can benefit most from antiplatelet therapies, with varying degrees of benefit depending on whether these agents are being used for primary, secondary, or tertiary prevention. Importantly, the antiplatelet treatment regimens currently available have expanded and no longer limited to aspirin but include other drugs such as P2Y12 and phosphodiesterase inhibitors, also used in combination, as well as precision medicine approaches using genetic testing aiming at optimizing the safety and efficacy in this population.

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.

Influence of Desialylation on the Drug Binding Affinity of Human Alpha-1-Acid Glycoprotein Assessed by Microscale Thermophoresis

Human serum alpha-1-acid glycoprotein (AAG) is an acute-phase plasma protein involved in the binding and transport of many drugs, especially basic and lipophilic substances. The sialic acid groups that terminate the N-glycan chains of AAG have been reported to change in response to numerous health conditions and may have an impact on the binding of drugs to AAG. In this study, we quantified the binding between native and desialylated AAG and seven drugs from different pharmacotherapeutic groups (carvedilol, diltiazem, dipyridamole, imipramine, lidocaine, propranolol, vinblastine) using microscale thermophoresis (MST). This method was chosen due to its robustness and high sensitivity, allowing precise quantification of molecular interactions based on the thermophoretic movement of fluorescent molecules. Detailed glycan analysis of native and desialylated AAG showed over 98% reduction in sialic acid content for the enzymatically desialylated AAG. The MST results indicate that desialylation generally alters the binding affinity between AAG and drugs, leading to either an increase or decrease in Kd values, probably due to conformational changes of AAG caused by the different sialic acid content. This effect is also reflected in an increased denaturation temperature of desialylated AAG. Our findings indicate that desialylation impacts free drug concentrations differently, depending on the binding affinity of the drug with AAG relative to human serum albumin (HSA). For drugs such as dipyridamole, lidocaine, and carvedilol, which have a higher affinity for AAG, desialylation significantly changes free drug concentrations. In contrast, drugs such as propranolol, imipramine, and vinblastine, which have a strong albumin binding, show only minimal changes. It is noteworthy that the free drug concentration of dipyridamole is particularly sensitive to changes in AAG concentration and glycosylation, with a decrease of up to 15% being observed, underscoring the need for dosage adjustments in personalized medicine.

Dual Antiplatelet Therapy for the Acute Management and Long-term Secondary Prevention of Ischemic Stroke and Transient Ischemic Attack, An Updated Review

To improve the efficacy over antiplatelet monotherapy, dual antiplatelet therapy (DAPT) has been increasingly adopted in the management of non-cardioembolic stroke. For minor ischemic stroke and high-risk transient ischemic attack, the aspirin-clopidogrel combination is now recommended for acute short-term treatment, whereas aspirin-ticagrelor combination may be considered in selected patients, especially those with resistance to clopidogrel. For long-term stroke prevention, aspirin-dipyridamole combination has been used as an alternative to antiplatelet monotherapy, and aspirin or clopidogrel combined with cilostazole may be prescribed for added protection in high-risk patients. In this paper, we review the development of DAPT from a historical perspective and describe the findings from major clinical trials published up until the end of 2023. Using the 2021 American Heart Association guideline for secondary stroke prevention as a basis for our recommendations, we further discuss areas of controversy and more recent developments to provide an updated review for clinicians to consider in their daily practice.

Novel strategies in antithrombotic therapy: targeting thrombosis while preserving hemostasis

Antithrombotic therapy is a delicate balance between the benefits of preventing a thrombotic event and the risks of inducing a major bleed. Traditional approaches have included antiplatelet and anticoagulant medications, require careful dosing and monitoring, and all carry some risk of bleeding. In recent years, several new targets have been identified, both in the platelet and coagulation systems, which may mitigate this bleeding risk. In this review, we briefly describe the current state of antithrombotic therapy, and then present a detailed discussion of the new generation of drugs that are being developed to target more safely existing or newly identified pathways, alongside the strategies to reverse direct oral anticoagulants, showcasing the breadth of approaches. Combined, these exciting advances in antithrombotic therapy bring us closer than we have ever been to the "holy grail" of the field, a treatment that separates the hemostatic and thrombotic systems, preventing clots without any concurrent bleeding risk.

Antithrombotic Therapy for Primary and Secondary Prevention of Ischemic Stroke: JACC State-of-the-Art Review

Stroke is a devastating condition with significant morbidity and mortality worldwide. Antithrombotic therapy plays a crucial role in both primary and secondary prevention of stroke events. Single or dual antiplatelet therapy is generally preferred in cases of large-artery atherosclerosis and small-vessel disease, whereas anticoagulation is recommended in conditions of blood stasis or hypercoagulable states that mostly result in red thrombi. However, the benefit of antithrombotic therapies must be weighed against the increased risk of bleeding, which can pose significant challenges in the pharmacological management of this condition. This review provides a comprehensive summary of the currently available evidence on antithrombotic therapy for ischemic stroke and outlines an updated therapeutic algorithm to support physicians in tailoring the strategy to the individual patient and the underlying mechanism of stroke.

Drugs targeting adenosine signaling pathways: A current view

Adenosine is an endogenous nucleoside that regulates many physiological and pathological processes. It is derived from either the intracellular or extracellular dephosphorylation of adenosine triphosphate and interacts with cell-surface G-protein-coupled receptors. Adenosine plays a substantial role in protecting against cell damage in areas of increased tissue metabolism and preventing organ dysfunction in pathological states. Targeting adenosine metabolism and receptor signaling may be an effective therapeutic approach for human diseases, including cardiovascular and central nervous system disorders, rheumatoid arthritis, asthma, renal diseases, and cancer. Several lines of evidence have shown that many drugs exert their beneficial effects by modulating adenosine signaling pathways but this knowledge urgently needs to be summarized, and most importantly, actualized. The present review collects pharmaceuticals and pharmacological or diagnostic tools that target adenosine signaling in their primary or secondary mode of action. We overviewed FDA-approved drugs as well as those currently being studied in clinical trials. Among them are already used in clinic A2A adenosine receptor modulators like istradefylline or regadenoson, but also plenty of anti-platelet, anti-inflammatory, or immunosuppressive, and anti-cancer drugs. On the other hand, we investigated dozens of specific adenosine pathway regulators that are tested in clinical trials to treat human infectious and noninfectious diseases. In conclusion, targeting purinergic signaling represents a great therapeutic challenge. The actual knowledge of the involvement of adenosinergic signaling as part of the mechanism of action of old drugs has open a path not only for drug-repurposing but also for new therapeutic strategies.

Current concepts and novel targets for antiplatelet therapy

Platelets have a crucial role in haemostasis and atherothrombosis. Pharmacological control of platelet hyper-reactivity has become a cornerstone in the prevention of thrombo-ischaemic complications in atherosclerotic diseases. Current antiplatelet therapies substantially improve clinical outcomes in patients with coronary artery disease, but at the cost of increased risk of bleeding. Beyond their role in thrombosis, platelets are known to regulate inflammatory (thrombo-inflammatory) and microcirculatory pathways. Therefore, controlling platelet hyper-reactivity might have implications for both tissue inflammation (myocardial ischaemia) and vascular inflammation (vulnerable plaque formation) to prevent atherosclerosis. In this Review, we summarize the pathophysiological role of platelets in acute myocardial ischaemia, vascular inflammation and atherosclerotic progression. Furthermore, we highlight current clinical concepts of antiplatelet therapy that have contributed to improving patient care and have facilitated more individualized therapy. Finally, we discuss novel therapeutic targets and compounds for antiplatelet therapy that are currently in preclinical development, some of which have a more favourable safety profile than currently approved drugs with regard to bleeding risk. These novel antiplatelet targets might offer new strategies to treat cardiovascular disease.

A Contemporary Review of Antiplatelet Therapies in Current Clinical Practice

Antiplatelet therapy plays a crucial role in a number of cardiovascular disorders. We currently have a range of antiplatelet agents in our armamentarium. In this review, we aim to summarise the common antiplatelet agents currently available, and their use in clinic practice. We not only highlight recent trials exploring antiplatelet therapy in atherosclerotic cardiovascular disease, but also in trials related to transcatheter aortic valve implantation and coronavirus disease 2019. Inevitably, the antithrombotic benefits of these drugs are accompanied by an increase in bleeding complications. Therefore, an individualised approach to weighing each patient's thrombotic risk versus bleeding risk is imperative, in order to improve clinical outcomes.

Genotype-guided dual antiplatelet therapy in cerebrovascular disease: assessing the risk and benefits for ethnic populations

INTRODUCTION

Cerebrovascular disease is a leading cause of morbidity and mortality in the world and antiplatelet therapy is a main pharmacologic means of secondary prevention. Clinical information has accumulated about benefit of dual antiplatelet therapy in certain clinical scenarios, genetic causes of antiplatelet resistance and its effect on clinical outcomes, and ethnic and geographic distributions of genetic polymorphisms.

AREAS COVERED

This review covers literature related to the pharmacogenomics of antiplatelet agents with a focus on ethnic variability, antiplatelet resistance, and dual antiplatelet therapy in cerebrovascular disease.

EXPERT OPINION

Selecting patients for dual antiplatelet therapy and specific agents require consideration of multiple factors. Ethnic factors should be considered in certain circumstances, but additional research is needed to determine the generalizability of the findings.

Antithrombotic therapy in antiphospholipid syndrome with arterial thrombosis: a systematic review and network meta-analysis

Introduction

The optimal secondary thromboprophylactic strategies for patients with antiphospholipid syndrome (APS) and arterial thrombosis remain controversial. This study aimed to evaluate the comparative efficacy and safety of various antithrombotic strategies in APS with arterial thrombosis.

Methods

A comprehensive literature search was conducted using OVID MEDLINE, EMBASE, Web of Science, and the Cochrane Controlled Register of Trials (CENTRAL) from inception until 30 September 2022, with no language restrictions. The inclusion criteria for eligible studies were as follows: inclusion of APS patients with arterial thrombosis, treatment with either antiplatelet agents, warfarin, direct oral anticoagulants (DOACs), or a combination of these therapies, and reporting of recurrent thrombotic events.

Results

We conducted a frequentist random-effects network meta-analysis (NMA) involving 13 studies with a total of 719 participants, comprising six randomized and seven non-randomized studies. In comparison to single antiplatelet therapy (SAPT), the combined use of antiplatelet and warfarin demonstrated a significant reduction in the risk of recurrent overall thrombosis, with a risk ratio (RR) of 0.41 (95% CI 0.20 to 0.85). Dual antiplatelet therapy (DAPT) showed a lower risk of recurrent arterial thrombosis compared to SAPT although the difference did not reach statistical significance, with an RR of 0.29 (95% CI 0.08 to 1.07). DOAC was associated with a significant increase in the risk of recurrent arterial thrombosis, with an RR of 4.06 (95% CI 1.33 to 12.40) when compared to SAPT. There was no significant difference in major bleeding among various antithrombotic strategies.

Discussion

Based on this NMA, the combination of warfarin and antiplatelet therapy appears to be an effective approach in preventing recurrent overall thrombosis in APS patients with a history of arterial thrombosis. While DAPT may also show promise in preventing recurrent arterial thrombosis, further studies are needed to confirm its efficacy. Conversely, the use of DOACs was found to significantly increase the risk of recurrent arterial thrombosis.

Contemporary Antiplatelet and Anticoagulant Therapies for Secondary Stroke Prevention: A Narrative Review of Current Literature and Guidelines

PURPOSE OF REVIEW

Stroke is a leading cause of death and disability worldwide. The annual incidence of new or recurrent stroke is approximately 795,000 cases per year in the United States, of which 87% are ischemic in nature. In addition to the management of modifiable high-risk factors to reduce the risk of recurrent stroke, antithrombotic agents (antiplatelets and anticoagulants) play an important role in secondary stroke prevention. This review will discuss the published literature on the use of antiplatelets and anticoagulants in secondary prevention of acute ischemic stroke and transient ischemic attack (TIA), including their pharmacology, efficacy, and adverse effects. We will also highlight the role of dual antiplatelet therapy (DAPT) in secondary stroke prevention, along with supporting literature.

RECENT FINDINGS

Single antiplatelet therapy (SAPT) with aspirin or clopidogrel reduces the risk of recurrent ischemic stroke in patients with non-cardioembolic ischemic stroke or TIA. However, as shown in recent trials, short-term DAPT with aspirin and clopidogrel or ticagrelor for 21-30 days is more effective than SAPT in patients with minor acute non-cardioembolic stroke or high-risk TIA. Although short-term DAPT is highly effective in preventing recurrent stroke, a more prolonged course can increase bleeding risks without additional benefit. DAPT for 90 days, followed by aspirin monotherapy for patients with large vessel intracranial atherosclerotic disease, is suitable for secondary stroke prevention. However, patients need to be monitored for both minor (e.g., bruising) and major (e.g., intracranial) bleeding complications. Conversely, oral warfarin and newer direct oral anticoagulant (DOACs) such as dabigatran, rivaroxaban, apixaban, and edoxaban are the agents of choice for secondary stroke prevention in patients with non-valvular cardioembolic strokes. DOACs may be preferred over warfarin due to decreased bleeding risks, including ICH, lack of need for international normalized ratio monitoring, no dietary restrictions, and limited drug-drug interactions. The choice between different antiplatelets and anticoagulants for prevention of ischemic stroke depends on the underlying stroke mechanism, cytochrome P450 2C19 polymorphisms, bleeding risk profile, compliance, drug tolerance, and drug resistance. Physicians must carefully weigh each patient's relative benefits and bleeding risks before initiating an antiplatelet/anticoagulant treatment regimen. Further studies are warranted to study the optimal duration of DAPT in symptomatic intracranial atherosclerosis since the benefit is most pronounced in the short term while the bleeding risk remains high during the extended duration of therapy.

Dual antiplatelet therapy with cilostazol in stroke patients with extracranial arterial stenosis or without arterial stenosis: A subgroup analysis of the CSPS.com trial

BACKGROUND

We previously reported that dual antiplatelet therapy (DAPT) with cilostazol was superior to aspirin or clopidogrel for the prevention of recurrent stroke and vascular events in a subgroup analysis of intracranial arterial stenosis in the Cilostazol Stroke Prevention Study for Antiplatelet Combination (CSPS.com), a randomized controlled trial.

AIMS

We conducted another subgroup analysis to investigate the benefit of DAPT with cilostazol in patients with extracranial arterial stenosis (ECAS) and those without arterial stenosis.

METHODS

We compared the risk of recurrent ischemic stroke, vascular events, and major bleeding between DAPT with cilostazol plus aspirin or clopidogrel and aspirin or clopidogrel alone in patients with ischemic stroke between 8 and 180 days before starting trial treatment and ECAS or without arterial stenosis.

RESULTS

The median follow-up period was 1.4 years. The risk of recurrent ischemic stroke (hazard ratio (HR): 1.04, 95% confidence interval (CI): 0.42-2.57) and vascular events (HR: 0.97, 95% CI: 0.42-2.24) did not differ between the two groups for the 253 patients with ECAS, whereas they were lower (HR: 0.36, 95% CI: 0.18-0.74 and HR: 0.47, 95% CI: 0.26-0.85, respectively) in the DAPT group for the 944 patients without arterial stenosis. The risk of major bleeding did not differ between the groups in patients with ECAS (HR: 0.58, 95% CI: 0.05-6.39) or without arterial stenosis (HR: 0.79, 95% CI: 0.27-2.26).

CONCLUSION

DAPT with cilostazol might be beneficial for prevention of recurrent stroke and vascular events in patients without arterial stenosis but not in those with ECAS.

DATA ACCESS STATEMENT

We will make the deidentified participant data from this research available to the scientific community with as few restrictions as feasible, while retaining exclusive use until the publication of major output.

Dual Antiplatelet Therapy With Cilostazol for Secondary Prevention in Lacunar Stroke: Subanalysis of the CSPS.com Trial

BACKGROUND

The effectiveness of long-term dual antiplatelet therapy (DAPT) to prevent recurrent strokes in patients with lacunar stroke remains unclarified. Therefore, this study aimed to compare and to elucidate the safety and effectiveness of DAPT and single antiplatelet therapy (SAPT) in preventing recurrence in chronic lacunar stroke.

METHODS

CSPS.com (Cilostazol Stroke Prevention Study for Antiplatelet Combination) was a prospective, multicenter, randomized controlled trial. In this prespecified subanalysis, 925 patients (mean age, 69.5 years; 69.4% men) with lacunar stroke were selected from 1884 patients with high-risk noncardioembolic stroke, enrolled in the CSPS.com trial after 8 to 180 days following stroke. Patients were randomly assigned to receive either SAPT or DAPT using cilostazol and were followed for 0.5 to 3.5 years. The primary efficacy outcome was the first recurrence of ischemic stroke. The safety outcomes were severe or life-threatening bleeding.

RESULTS

The DAPT group receiving cilostazol and either aspirin or clopidogrel and SAPT group receiving aspirin or clopidogrel alone comprised 464 (50.2%) and 461 (49.8%) patients, respectively. Ischemic stroke occurred in 12 of 464 patients (1.84 per 100 patient-years) in the DAPT group and 31 of 461 patients (4.42 per 100 patient-years) in the SAPT group, during follow-up. After adjusting for multiple potential confounding factors, ischemic stroke risk was significantly lower in the DAPT group than in the SAPT group (hazard ratio, 0.43 [95% CI, 0.22-0.84]). The rate of severe or life-threatening hemorrhage did not differ significantly between the groups (2 patients [0.31 per 100 patient-years] versus 6 patients [0.86 per 100 patient-years] in the DAPT and SAPT groups, respectively; hazard ratio, 0.36 [95% CI, 0.07-1.81]).

CONCLUSIONS

In patients with lacunar stroke, DAPT using cilostazol had significant benefits in reducing recurrent ischemic stroke incidence compared with SAPT without increasing the risk of severe or life-threatening bleeding.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01995370. URL: https://www.umin.ac.jp/ctr; Unique identifier: UMIN000012180.

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.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Platelet function testing using the Multiplate analyzer after administration of aspirin in Aachen minipigs

Knowledge of platelet function in pigs and the effectiveness of antiplatelet therapy is important to ensure proper transferability from animal studies to humans. Our aim was to (1) characterize baseline platelet function of Aachen minipigs using the bedside Multiplate analyzer, (2) compare baseline platelet function with Göttingen minipigs, and (3) characterize platelet inhibition within the first 5 minutes after intravenous administration of acetylsalicylic acid (ASA). We characterized the baseline platelet function and hematological parameters in 9 Aachen minipigs. Historical data of 8 unmedicated Göttingen minipigs were used for comparison of baseline values. Platelet inhibition in Aachen minipigs was tested 1-5 minutes after intravenous administration of 500 mg ASA. Multiplate examinations included the following tests: ASPI test (to assess the effect of ASA), adenosine-diphosphate-test (ADP test) and thrombin receptor activating peptide test (TRAP test). Median values and interquartile range (IQR) of the Multiplate baseline tests in Aachen minipigs were as follows: ASPI: 39 U (IQR = 21-71), ADP: 70 U (IQR = 48-73), and TRAP: 8 U (IQR = 6-9), whereas the values in Göttingen minipigs were as follows: ASPI: 70.5 U (IQR = 60-78), ADP: 51 U (IQR = 45-66), and TRAP: 6.5 U (IQR = 4-8). ASPI values of Göttingen minipigs were significantly higher than those of Aachen minipigs (p = 0.046). Intravenous administration of ASA in Aachen minipigs resulted in significant platelet inhibition after 1 minute, which remained stable over a period of 5 minutes (p≤0.038). Aachen minipigs appeared to have a high variance in arachidonic acid-mediated platelet aggregation. In Aachen minipigs, intravenous ASA administration resulted in immediate platelet inhibition.

Quantitative Proteomics of Medium-Sized Extracellular Vesicle-Enriched Plasma of Lacunar Infarction for the Discovery of Prognostic Biomarkers

Lacunar infarction (LACI), a subtype of acute ischemic stroke, has poor mid- to long-term prognosis due to recurrent vascular events or incident dementia which is difficult to predict using existing clinical data. Herein, we aim to discover blood-based biomarkers for LACI as a complementary prognostic tool. Convalescent plasma was collected from forty-five patients following a non-disabling LACI along with seventeen matched control subjects. The patients were followed up prospectively for up to five years to record an occurrence of adverse outcome and grouped accordingly (i.e., LACI-no adverse outcome, LACI-recurrent vascular event, and LACI-cognitive decline without any recurrence of vascular events). Medium-sized extracellular vesicles (MEVs), isolated from the pooled plasma of four groups, were analyzed by stable isotope labeling and 2D-LC-MS/MS. Out of 573 (FDR < 1%) quantified proteins, 146 showed significant changes in at least one LACI group when compared to matched healthy control. A systems analysis revealed that major elements (~85%) of the MEV proteome are different from the proteome of small-sized extracellular vesicles obtained from the same pooled plasma. The altered MEV proteins in LACI patients are mostly reduced in abundance. The majority of the shortlisted MEV proteins are not linked to commonly studied biological processes such as coagulation, fibrinolysis, or inflammation. Instead, they are linked to oxygen-glucose deprivation, endo-lysosomal trafficking, glucose transport, and iron homeostasis. The dataset is provided as a web-based data resource to facilitate meta-analysis, data integration, and targeted large-scale validation.

Antiplatelet treatment for acute secondary prevention of non-cardioembolic minor stroke / transient ischaemic attack: an update for the acute physician

Acute stroke is the leading cause of disability in the UK and a leading cause of mortality worldwide. The majority of patients with ischaemic stroke present with minor deficits or transient ischaemic attack (TIA), and are often first seen by patient-facing clinicians. Urgent evaluation and treatment are important as many patients are at high risk of major vascular events and death within hours to days after the index event. This narrative review summarises the evidence on four antiplatelet treatments for non-cardioembolic stroke prevention: aspirin, clopidogrel, dipyridamole and ticagrelor. Each of these drugs has a unique mechanism and has been tested as a single agent or in combination. Aspirin, when given early is beneficial and short-term treatment with aspirin and clopidogrel has been shown to be more effective in high-risk TIA / minor stroke. This review concludes by highlighting gaps in evidence, including scope for future trials that could potentially change clinical practice.

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.

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.

Antiplatelet Therapy in Atherothrombotic Diseases: Similarities and Differences Across Guidelines

Antiplatelet therapy, mainly consisting of aspirin and P2Y₁₂ receptor antagonists, is the cornerstone of the pharmacological treatment and prevention of atherothrombotic diseases. Its use, especially in secondary cardiovascular prevention, has significantly improved patient clinical outcomes in the last decades. Primary safety endpoint (i.e., bleeding complications) remain a major drawback of antiplatelet drugs. National and international societies have published and regularly updated guidelines for antiplatelet therapy aiming to provide clinicians with practical recommendations for a better handling of these drugs in various clinical settings. Many recommendations find common ground between international guidelines, but certain strategies vary across the countries, particularly with regard to the choice of molecules, dosage, and treatment duration. In this review, we detail and discuss the main antiplatelet therapy indications in the light of the different published guidelines and the significant number of recently published clinical trials and meta-analyses and highlight the areas that deserve further investigation in order to improve antiplatelet therapy in patients with atherothrombotic diseases.

Investigational drugs for ischemic stroke: what's in the clinical development pipeline for acute phase and prevention?

INTRODUCTION

Stroke is a leading cause of disability and mortality and its burden expected to increase. The only approved drug for acute ischemic stroke is the intravenous thrombolytic alteplase. The risk of bleeding complications is one of the reasons for the undertreatment of eligible patients. Numerous drugs are currently being developed to improve safety-efficacy.

AREAS COVERED

We reviewed literature from January 1^st, 2000, to 15^th January 2022 for the development and testing of novel drugs with the aim of targeting treatment at prevention of ischemic stroke: PubMed, MEDLINE, Google Scholar, and ClinicalTrial.gov.

EXPERT OPINION

The pathophysiology of ischemic stroke involves multiple pathways causing cerebral artery obstruction and brain tissue ischemia. Data suggest that tenecteplase is a more promising fibrinolytic agent with a superior efficacy-safety profile, compared to the currently approved alteplase. Current guidelines consider a short-term cycle of mannitol or hypertonic saline to be advisable in patients with space-occupying hemispheric infarction. Regarding primary and secondary prevention, research is primarily focused on identifying mechanisms to improve the safety-efficacy profile using a "hemostasis-sparing" approach. Further evaluation on those agents that have already shown promise for their risk/benefit profiles, would benefit greatly a neurologist's capacity to successfully prevent and treat ischemic stroke patients.

2022 Prevention of chronic non-communicable diseases in Of the Russian Federation. National guidelines

.

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.

Trends in Mortality Due to Myocardial Infarction, Stroke, and Pulmonary Embolism in Patients Receiving Dialysis

IMPORTANCE

During the past decades, improvements in the prevention and management of myocardial infarction, stroke, and pulmonary embolism have led to a decline in cardiovascular mortality in the general population. However, it is unknown whether patients receiving dialysis have also benefited from these improvements.

OBJECTIVE

To assess the mortality rates for myocardial infarction, stroke, and pulmonary embolism in a large cohort of European patients receiving dialysis compared with the general population.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, adult patients who started dialysis between 1998 and 2015 from 11 European countries providing data to the European Renal Association Registry were and followed up for 3 years. Data were analyzed from September 2020 to February 2022.

EXPOSURES

Start of dialysis.

MAIN OUTCOMES AND MEASURES

The age- and sex-standardized mortality rate ratios (SMRs) with 95% CIs were calculated by dividing the mortality rates in patients receiving dialysis by the mortality rates in the general population for 3 equal periods (1998-2003, 2004-2009, and 2010-2015).

RESULTS

In total, 220 467 patients receiving dialysis were included in the study. Their median (IQR) age was 68.2 (56.5-76.4) years, and 82 068 patients (37.2%) were female. During follow-up, 83 912 patients died, of whom 7662 (9.1%) died because of myocardial infarction, 5030 (6.0%) died because of stroke, and 435 (0.5%) died because of pulmonary embolism. Between the periods 1998 to 2003 and 2010 to 2015, the SMR of myocardial infarction decreased from 8.1 (95% CI, 7.8-8.3) to 6.8 (95% CI, 6.5-7.1), the SMR of stroke decreased from 7.3 (95% CI, 7.0-7.6) to 5.8 (95% CI, 5.5-6.2), and the SMR of pulmonary embolism decreased from 8.7 (95% CI, 7.6-10.1) to 5.5 (95% CI, 4.5-6.6).

CONCLUSIONS AND RELEVANCE

In this cohort study of patients receiving dialysis, mortality rates for myocardial infarction, stroke, and pulmonary embolism decreased more over time than in the general population.

Antiplatelet Use in Ischemic Stroke

Objective:

A literature review of antiplatelet agents for primary and secondary stroke prevention, including mechanism of action, cost, and reasons for lack of benefit.

Data sources:

Articles were gathered from MEDLINE, Cochrane Reviews, and PubMed databases (1980-2021). Abstracts from scientific meetings were considered. Search terms included ischemic stroke, aspirin, clopidogrel, dipyridamole, ticagrelor, cilostazol, prasugrel, glycoprotein IIb/IIIa inhibitors.

Study selection and data extraction:

English-language original and review articles were evaluated. Guidelines from multiple countries were reviewed. Articles were evaluated independently by 2 authors.

Data synthesis:

An abundance of evidence supports aspirin and clopidogrel use for secondary stroke prevention. In the acute phase (first 21 days postinitial stroke), these medications have higher efficacy for preventing further stroke when combined, but long-term combination therapy is associated with higher hemorrhage rates. Antiplatelet treatment failure is influenced by poor adherence and genetic polymorphisms. Antiplatelet agents such as cilostazol may provide extra benefit over clopidogrel and aspirin, in certain racial groups, but further research in more diverse ethnic populations is needed.

Relevance to patient care and clinical practice:

This review presents the data available on the use of different antiplatelet agents poststroke. Dual therapy, recurrence after initiation of secondary preventative therapy, and areas for future research are discussed.

Conclusions:

Although good evidence exists for the use of certain antiplatelet agents postischemic stroke, there are considerable opportunities for future research to investigate personalized therapies. These include screening patients for platelet polymorphisms that confer antiplatelet resistance and for randomized trials including more racially diverse populations.

Effects of Dose Titration on Dipyridamole-Induced Headache: A Randomized, Double-Blind Clinical Trial

PURPOSE

The aim of this study is to investigate the effect of gradual dipyridamole titration and the incidence of dipyridamole-induced headache in patients with ischemic stroke or transient ischemic attack (TIA).

METHODS

A randomized, double-blind, double-placebo, parallel group, phase 4 clinical trial (KCT0005457) was conducted between July 1, 2019, and February 25, 2020, at 15 medical centers in South Korea. The study included patients aged >19 years diagnosed with a noncardioembolic ischemic stroke or TIA within the previous 3 weeks. The participants were randomized 1:1:1 to receive Adinox® (aspirin 25 mg/dipyridamole 200 mg) and aspirin (100 mg) once daily for the first 2 weeks followed by Adinox® twice daily for 2 weeks (titration group), Adinox® twice daily for 4 weeks (standard group), and aspirin 100 mg once daily for 4 weeks (control group). The primary endpoint was incidence of headache over 4 weeks. The key secondary endpoint was mean cumulative headache.

RESULTS

Ninety-six patients were randomized into the titration (n = 31), standard (n = 32), and control (n = 33) groups. The titration and standard groups (74.1% vs. 74.2%, respectively) showed no difference in the primary endpoint. However, the mean cumulated headache was significantly lower in the titration group than in the standard group (0.31 ± 0.46 vs. 0.58 ± 0.51, p = 0.023). Further, adverse drug reactions were more common in the standard group than in the titration group (28.1% vs. 9.7%, respectively, p = 0.054), although not significantly different.

CONCLUSION

The titration strategy was effective in lowering the incidence of cumulative dipyridamole-induced headache.

Antiplatelet therapy in cardiovascular disease: current status and future directions

Antiplatelet medications remain a cornerstone of therapy for atherosclerotic cardiovascular and cerebrovascular diseases. In primary prevention (patients with cardiovascular risk factors but no documented events, symptoms or angiographic disease), there is little evidence of benefit of any antiplatelet therapy, and such therapy carries the risk of excess bleeding. Where there is documented disease (secondary prevention), stable patients benefit from long-term antiplatelet monotherapy, aspirin being first choice in those with coronary heart disease and clopidogrel in those with cerebrovascular disease; moreover, recent evidence shows that low-dose rivaroxaban in combination with aspirin confers added benefit, in patients with stable cardiovascular and peripheral arterial disease. In patients with acute cerebrovascular disease, aspirin combined with clopidogrel reduces subsequent risk, while in acute coronary syndrome, dual antiplatelet therapy comprising aspirin and a P2Y₁₂ inhibitor (clopidogrel, prasugrel or ticagrelor) confers greater protection than aspirin monotherapy, with prasugrel and ticagrelor offering greater antiplatelet efficacy with faster onset of action than clopidogrel. Although greater antiplatelet efficacy is advantageous in preventing thrombotic events, this must be tempered by increased risk of bleeding which may be a particular issue in certain patient groups, as will be discussed. We will also discuss possible future approaches to personalisation of antiplatelet therapy.

Antithrombotic Therapy in the Prevention of Stroke

OVERVIEW

Ischemic stroke is a leading cause of death and disability throughout the world. Antithrombotic therapy, which includes both antiplatelet and anticoagulant agents, is a primary medication of choice for the secondary prevention of stroke. However, the choices vary with the need to incorporate evolving, newer information into the clinical scenario. There is also the need to factor in co-morbid medical conditions as well as the cost ramifications for a particular patient as well as compliance with the regimen. Pertinent Updates: In the acute setting, dual antiplatelet therapy from three weeks to up to three months has become recognized as a reasonable approach for patients with either minor stroke or transient ischemic attack or those with symptoms associated with higher-grade intracranial stenosis. This approach is favored for non-cardioembolic stroke as a cardiogenic mechanism tends to be best managed with attention to the cardiac condition as well as anticoagulant therapy. Risk stratification for recurrent stroke is important in weighing potential risk versus benefits. For example, prolonged dual antiplatelet therapy, with a combination such as aspirin and clopidogrel or aspirin and ticagrelor, tends to have negation of the potential clinical benefit of stroke prevention, over time, by the enhanced bleeding risk. Anticoagulant choices are now impacted by newer agents, initially identified as novel oral anticoagulants (NOACs), which also became associated with "non-vitamin K" agents as they are no longer considered novel. Alternatively, they are now often identified as direct oral anticoagulants (DOACs). They tend to be viewed as superior or non-inferior to warfarin with the caveat that warfarin is still viewed as the agent of choice for stroke prevention in patients with mechanical heart valves.

CONCLUSION

Based upon cumulative information from multiple clinical trials of secondary prevention of stroke, there is an increasing array of approaches in an effort to provide optimal management. Antithrombotic therapy, including in combination with anticoagulant therapy, continues to evolve with the general caveat that "one size does not fit all". In view of this, we desire to provide an evidence-based approach for the prevention of stroke with antithrombotic agents.

Assessment of Nonfatal Myocardial Infarction as a Surrogate for All-Cause and Cardiovascular Mortality in Treatment or Prevention of Coronary Artery Disease: A Meta-analysis of Randomized Clinical Trials

IMPORTANCE

Although nonfatal myocardial infarction (MI) is associated with an increased risk of mortality, evidence validating nonfatal MI as a surrogate end point for all-cause or cardiovascular (CV) mortality is lacking.

OBJECTIVE

To examine whether nonfatal MI may be a surrogate for all-cause or CV mortality in patients with or at risk for coronary artery disease.

DATA SOURCES

In this meta-analysis, PubMed was searched from inception until December 31, 2020, for randomized clinical trials of interventions to treat or prevent coronary artery disease reporting mortality and nonfatal MI published in 3 leading journals.

STUDY SELECTION

Randomized clinical trials including at least 1000 patients with 24 months of follow-up.

DATA EXTRACTION AND SYNTHESIS

Trial-level correlations between nonfatal MI and all-cause or CV mortality were assessed for surrogacy using the coefficient of determination (R2). The criterion for surrogacy was set at 0.8. Subgroup analyses based on study subject (primary prevention, secondary prevention, mixed primary and secondary prevention, and revascularization), era of trial (before 2000, 2000-2009, and 2010 and after), and follow-up duration (2.0-3.9, 4.0-5.9, and ≥6.0 years) were performed.

MAIN OUTCOMES AND MEASURES

All-cause or CV mortality and nonfatal MI.

RESULTS

A total of 144 articles randomizing 1 211 897 patients met the criteria for inclusion. Nonfatal MI did not meet the threshold for surrogacy for all-cause (R2 = 0.02; 95% CI, 0.00-0.08) or CV (R2 = 0.11; 95% CI, 0.02-0.27) mortality. Nonfatal MI was not a surrogate for all-cause mortality in primary (R2 = 0.01; 95% CI, 0.001-0.26), secondary (R2 = 0.03; 95% CI, 0.00-0.20), mixed primary and secondary prevention (R2 = 0.001; 95% CI, 0.00-0.08), or revascularization trials (R2 = 0.21; 95% CI, 0.002-0.50). For trials enrolling patients before 2000 (R2 = 0.22; 95% CI, 0.08-0.36), between 2000 and 2009 (R2 = 0.02; 95% CI, 0.00-0.17), and from 2010 and after (R2 = 0.01; 95% CI, 0.00-0.09), nonfatal MI was not a surrogate for all-cause mortality. Nonfatal MI was not a surrogate for all-cause mortality in randomized clinical trials with 2.0 to 3.9 (R2 = 0.004; 95% CI, 0.00-0.08), 4.0 to 5.9 (R2 = 0.06; 95% CI, 0.001-0.16), or 6.0 or more years of follow-up (R2 = 0.30; 95% CI, 0.01-0.55).

CONCLUSIONS AND RELEVANCE

The findings of this meta-analysis do not appear to establish nonfatal MI as a surrogate for all-cause or CV mortality in randomized clinical trials of interventions to treat or prevent coronary artery disease.

Intracranial Atherosclerotic Disease: Current Concepts in Medical and Surgical Management

PURPOSE OF THE REVIEW

This article reviews the current concepts in intracranial atherosclerotic disease (ICAD) as a common etiology of ischemic stroke; pathophysiologic mechanisms of ischemic stroke; diagnostic evaluation; and therapeutic modalities, including maximal medical therapy (MMT), percutaneous transluminal angioplasty and stenting (PTAS), and bypass surgery.

RECENT FINDINGS

Data from recent studies demonstrate that proper patient selection and timing of procedure and standardized PTAS techniques by experienced operators resulted in acceptably low periprocedural adverse events for patients who failed MMT.

SUMMARY

ICAD is a common cause of ischemic stroke. Complex pathology and high rates of recurrent and disabling ischemic strokes despite currently available treatments make ICAD the most challenging to treat of all ischemic stroke etiologies. Randomized trials previously showed that MMT, which involves the use of combinations of antiplatelet medications, targeted control of hypertension and serum low-density lipoprotein cholesterol, and adequate management of body weight through lifestyle modification, was superior to PTAS in decreasing rates of recurrent ischemic strokes from symptomatic ICAD. MMT performed better than expected, while periprocedural complications were significantly higher than expected in PTAS. Meanwhile, high rates of recurrent ischemic stroke despite MMT remain a great challenge. New clinical evidence continues to emerge on a safer application of PTAS, which is currently offered to a subset of patients who present with recurrent ischemic strokes despite MMT.

Cilostazol for Secondary Stroke Prevention: History, Evidence, Limitations, and Possibilities

Cilostazol is a PDE3 (phosphodiesterase III) inhibitor with a long track record of safety that is Food and Drug Administration and European Medicines Agency approved for the treatment of claudication in patients with peripheral arterial disease. In addition, cilostazol has been approved for secondary stroke prevention in several Asian countries based on trials that have demonstrated a reduction in stroke recurrence among patients with noncardioembolic stroke. The onset of benefit appears after 60 to 90 days of treatment, which is consistent with cilostazol's pleiotropic effects on platelet aggregation, vascular remodeling, blood flow, and plasma lipids. Cilostazol appears safe and does not increase the risk of major bleeding when given alone or in combination with aspirin or clopidogrel. Adverse effects such as headache, gastrointestinal symptoms, and palpitations, however, contributed to a 6% increase in drug discontinuation among patients randomized to cilostazol in a large secondary stroke prevention trial (CSPS.com [Cilostazol Stroke Prevention Study for Antiplatelet Combination]). Due to limitations of prior trials, such as open-label design, premature trial termination, large loss to follow-up, lack of functional or cognitive outcome data, and exclusive enrollment in Asia, the existing trials have not led to a change in clinical practice or guidelines in Western countries. These limitations could be addressed by a double-blind placebo-controlled randomized trial conducted in a broader population. If positive, it would increase the evidence in support of long-term treatment with cilostazol for secondary prevention in the millions of patients worldwide who have experienced a noncardioembolic ischemic stroke.

Use of dipyridamole is associated with lower risk of lymphoid neoplasms: a propensity score-matched cohort study

The anti-cancer potential of dipyridamole has been suggested from experiments, but evidence from population-based studies is still lacking. We aimed to explore if dipyridamole use was related to a lower risk of lymphoid neoplasms. We identified individuals with prescription of aspirin after diagnosis of ischaemic cerebrovascular disease since 2006 by linking several Swedish registers. In these aspirin users, those with dipyridamole prescription were further identified as the study group and patients without dipyridamole were randomly selected as reference group with 1:1 ratio using a propensity score-matching approach. After a median of 6·67 years of follow-up, a total of 46 patients with dipyridamole use developed lymphoid neoplasms with an incidence rate of 0·49 per 1 000 person-years, while the rate in the matched group was 0·74 per 1 000 person-years. As compared to non-users, dipyridamole users were associated with a significantly decreased risk of lymphoid neoplasms [hazard ratio (HR) = 0·65; 95% confidence interval (CI) = 0·43-0·98]. Specifically, the reduced risk was observed for non-Hodgkin lymphomas (HR = 0·64; 95% CI = 0·42-0·94), especially B-cell lymphomas (HR = 0·56; 95% CI = 0·35-0·88). Dipyridamole use was related to a lower risk of lymphoid neoplasms, indicating a clinical potential of dipyridamole to be an adjunct anti-tumour agent against lymphoid neoplasms.

A Clinical Update on Antiplatelet Therapy in Secondary Prevention of Ischemic Stroke

PURPOSE OF REVIEW

Antiplatelet therapy remains the standard of care in secondary stroke prevention for non-cardioembolic ischemic stroke and transient ischemic attack. We aim to examine the use of antiplatelet agents in secondary prevention through highlighting relevant clinical trials and meta-analyses as well as providing commentary regarding our practice.

RECENT FINDINGS

In the POINT and CHANCE trials, dual antiplatelet therapy reduced recurrent stroke compared to aspirin monotherapy. Sub-analyses of these trials suggest that genetic polymorphisms could play a role in diminishing the effectiveness of clopidogrel. Similarly, THALES demonstrated better outcomes with ticagrelor-aspirin combination therapy over aspirin monotherapy. Combination antiplatelet therapy with aspirin and the P2Y12 inhibitors, clopidogrel and ticagrelor, reduced stroke recurrence in those presenting with mild ischemic stroke or high risk TIA. Genetic polymorphisms may play a role in determining the appropriate regimen. Questions remain regarding the optimal duration of combination antiplatelet therapy for various stroke etiologies.

Meta-Analysis of Usefulness of Antiplatelet Therapy in Ischemic Stroke or Transient Ischemic Attack

The efficacy of early administration of dual antiplatelet therapy (DAPT) for secondary prevention after acute ischemic stroke or transient ischemic attack (TIA) is uncertain. This systematic review and meta-analysis compares the safety and efficacy of early administration (<24 hours) of DAPT (using either clopidogrel or ticagrelor with aspirin) versus single antiplatelet therapy (SAPT; aspirin alone) in acute non-cardioembolic ischemic stroke or TIA, incorporating data from large randomized controlled trials. Published trials fulfilling our criteria were identified from an electronic search of MEDLINE, with key words including: "clopidogrel or ticagrelor", "aspirin", "ischemic stroke", "transient ischemic attack", and "randomized controlled trial". Included were 3 randomized controlled trials of 21,067 patients assessing early administration (<24 hours from symptom onset) of DAPT versus SAPT in non-cardioembolic acute ischemic stroke or TIA. Our efficacy outcomes were ischemic stroke and all-cause mortality. Our safety outcome was severe bleeding. We performed a meta-analysis to pool results with a hierarchical Bayesian random-effects model. Dual antiplatelet therapy significantly reduced the risk of ischemic stroke (hazard ratio [HR], 0.73; 95% credible interval [CrI]: 0.54, 0.97), while increasing the risk of severe bleeding (HR, 2.48; 95% CrI: 1.07, 5.26). There was a non-significant numerical trend toward increased mortality with DAPT (HR, 1.29; 95% CrI: 0.73, 2.23). These observations were robust under the sensitivity analysis. In the present systematic review and meta-analysis of randomized controlled trials, DAPT reduced the risk of ischemic stroke at the cost of an increase in severe bleeding. Additional trials examining the ideal timing of DAPT administration are needed to thoroughly investigate the role, if any, of routine DAPT in patients with non-cardioembolic ischemic stroke or high-risk TIA.

Oral antithrombotic therapy for the prevention of recurrent cerebrovascular events

Stroke is frequently a disabling and even life-threatening condition that has an ischemic cause in most cases. Transient ischemic attack (TIA) is a lower-risk condition that still exposes to the risk of future major cardiovascular events. The causes of stroke can be classified as cardioembolic disease, large vessel disease, small vessel disease, undetermined, or others. Cardioembolic disease and atherothrombosis of large arteries are the most common underlying processes of ischemic stroke and TIA. Therefore, antithrombotic therapy is a central strategy in the pharmacological management of these patients. However, because antithrombotic therapy provides ischemic protection at the price of increased bleeding, defining the fine balance between efficacy and safety is a clinical challenge. Numerous trials have recently defined the current indications to the use of anticoagulant and antiplatelet therapy in patients with various subtypes of ischemic stroke or TIA. In this review, we provide an updated appraisal of the currently available evidence on the use of various oral antithrombotic agents for prevention of recurrent events after an ischemic stroke or TIA.

Verbal communication of effect-sizes, possible comparators, and uncertainty of evidence in the Finnish clinical practice guidelines: Omitting effect-sizes and comparators without expressing much uncertainty

RATIONALE, AIMS, AND OBJECTIVES

Our aim was to investigate verbal representations of intervention effect-size, uncertainty of evidence, and possible intervention comparators in statements concerning effects of interventions in Finnish clinical practice guidelines.

METHOD

We selected 10 clinical practice guidelines on common diseases and risk factors published by The Finnish Medical Society Duodecim. All the statements that considered beneficial effects of interventions and that were graded with a level of evidence (levels A, high, to D, very low) were included in analyses. We assessed whether the statements verbally represented intervention effect-size, uncertainty of evidence or a possible comparator, and the reported outcome.

RESULTS

Of 385 statements, verbal representation of beneficial effect-sizes occurred in 25 (6%) statements. Most (72%) statements indicated that intervention had a beneficial effect, but did not specify effect-size. Less than half (42%) of the statements represented uncertainty verbally. Comparisons to placebo or no-treatment were rare (3%) and 18% of the statements compared interventions to other treatments. Against instructions, a considerable part (35%) of statements with B-level evidence did not represent uncertainty.

CONCLUSION

Communicating beneficial intervention effects, effect-sizes, possible comparators, and uncertainty of evidence require much broader attention in the clinical practice guideline context.

Prehemorrhage antiplatelet use in aneurysmal subarachnoid hemorrhage and impact on clinical outcome

Background

Literature is inconclusive regarding the association between antiplatelet agents use and outcome after aneurysmal subarachnoid hemorrhage.

Aims

To investigate the association between clinical outcome and prehemorrhage use in aneurysmal subarachnoid hemorrhage patients as well as the impact of thrombocyte transfusion on rebleed and clinical outcome.

Methods

Data were collected from prospective databases of two European tertiary reference centers for aneurysmal subarachnoid hemorrhage patients. Patients were divided into “antiplatelet-user” and “non-user” according to the use of acetylsalicylic acid prior to the hemorrhage. Primary outcome was poor clinical outcome at six months (Glasgow Outcome Scale score 1–3). Secondary outcomes were in-hospital mortality and impact of thrombocyte transfusion.

Results

Of the 1033 patients, 161 (15.6%) were antiplatelet users. The antiplatelet users were older with higher incidence of cardiovascular risk factors. Antiplatelet use was associated with poor outcome and in-hospital mortality. After correction for age, sex, World Federation of Neurosurgical Societies score, infarction and heart disorder, pre-hemorrhage acetylsalicylic acid use was only associated with poor clinical outcome at six months (adjusted OR 1.80, 95% CI 1.08–3.02). Thrombocyte transfusion was not associated with a reduction in rebleed or poor clinical outcome.

Conclusion

In this multicenter study, the prehemorrhage acetylsalicylic acid use in aneurysmal subarachnoid hemorrhage patients was independently associated with poor clinical outcome at six months. Thrombocyte transfusion was not associated with the rebleed rate or poor clinical outcome at six months.