High-dose acetylsalicylic acid after cerebral infarction. A Swedish Cooperative Study

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.

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.

Clinical decision-making: Challenging traditional assumptions

Clinical decision-making that best serves the interests of our patients requires the synthesis of evidence-based medicine, sound clinical judgment and guidelines. However, a relatively low percentage of clinical guidelines are based on well-designed prospective randomized clinical trials. Thus the foundation on which good clinical outcomes can be reasonably expected should be based on i) data derived from the most applicable and highest quality clinical studies available, and ii) 'tried and tested' clinical maxims acquired through experience that are, in turn, those ideas that are in keeping with a reasonable body of medical opinion. It follows that poor decision-making and unfavorable clinical outcomes can be linked to inappropriate or inferior quality evidence, or incorrectly conceived or implemented clinical judgment. Here we review selected areas of recent controversy in clinical cardiology, highlighting the critical role of evidence-based medicine when making informed clinical decisions to help avoid harm in our patients.

Chemogenetic inhibition of lateral habenula projections to the dorsal raphe nucleus reduces passive coping and perseverative reward seeking in rats

The lateral habenula (LHb) processes information about aversive experiences that contributes to the symptoms of stress disorders. Previously, we found that chemogenetic inhibition of rat LHb neurons reduced immobility in the forced swim test, but the downstream target of these neurons was not known. Using an intersectional viral vector strategy, we selectively transduced three different output pathways from the LHb by injecting AAV8-DIO-hM₄Di into the LHb and CAV2-CRE (a retrograde viral vector) into one of the three target areas as follows: dorsal raphe nucleus (DRN), ventral tegmental area (VTA), or rostromedial tegmentum (RMTg). Using the forced swim test, we found that chemogenetic inhibition of DRN-projecting LHb neurons reduced passive coping (immobility), whereas inhibition of the other pathways did not. Chemogenetic activation of DRN-projecting neurons using hM3Dq in another cohort did not further exacerbate immobility. We next examined the impact of inhibiting DRN-projecting LHb neurons on reward sensitivity, perseverative behavior, and anxiety-like behavior using saccharin preference testing, reward-omission testing, and open-field testing, respectively. There was no effect of inhibiting any of these pathways on reward sensitivity, locomotion, or anxiety-like behavior, but inhibiting DRN-projecting LHb neurons reduced perseverative licking during reward-omission testing, whereas activating these neurons increased perseverative licking. These results support the idea that inhibiting LHb projections to the DRN provides animals with resilience during highly stressful or frustrating conditions but not under low-stress circumstances, and that inhibiting these neurons may promote persistence in active coping strategies.

Effectiveness and patient safety of platelet aggregation inhibitors in the prevention of cardiovascular disease and ischemic stroke in older adults - a systematic review

BACKGROUND

Platelet aggregation inhibitors (PAI) are among the most frequently prescribed drugs in older people, though evidence about risks and benefits of their use in older adults is scarce. The objectives of this systematic review are firstly to identify the risks and benefits of their use in the prevention and treatment of vascular events in older adults, and secondly to develop recommendations on discontinuing PAI in this population if risks outweigh benefits.

METHODS

Staged systematic review consisting of three searches. Searches 1 and 2 identified systematic reviews and meta-analyses. Search 3 included controlled intervention and observational studies from review-articles not included in searches 1 and 2. All articles were assessed by two independent reviewers regarding the type of study, age of participants, type of intervention, and clinically relevant outcomes. After data extraction and quality appraisal we developed recommendations to stop the prescribing of specific drugs in older adults following the Grading of Recommendations Assessment Development and Evaluation (GRADE) methodology.

RESULTS

Overall, 2385 records were screened leading to an inclusion of 35 articles reporting on 22 systematic reviews and meta-analyses, 11 randomised controlled trials, and two observational studies. Mean ages ranged from 57.0 to 84.6 years. Ten studies included a subgroup analysis by age. Overall, based on the evaluated evidence, three recommendations were formulated. First, the use of acetylsalicylic acid (ASA) for primary prevention of cardiovascular disease (CVD) in older people cannot be recommended due to an uncertainty in the risk-benefit ratio (weak recommendation; low quality of evidence). Secondly, the combination of ASA and clopidogrel in patients without specific indications should be avoided (strong recommendation; moderate quality of evidence). Lastly, to improve the effectiveness and reduce the risks of stroke prevention therapy in older people with atrial fibrillation (AF) and a CHA₂DS₂-VASc score of ≥ 2, the use of ASA for the primary prevention of stroke should be discontinued in preference for the use of oral anticoagulants (weak recommendation; low quality of evidence).

CONCLUSIONS

The use of ASA for the primary prevention of CVD and the combination therapy of ASA and clopidogrel for the secondary prevention of vascular events in older people may not be justified. The use of oral anticoagulants instead of ASA in older people with atrial fibrillation may be recommended. Further high quality studies with older adults are needed.

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.

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.

Aspirin delimits platelet life span by proteasomal inhibition

Aspirin is widely used in clinical settings as an anti-inflammatory and anti-platelet drug due its inhibitory effect on cyclooxygenase activity. Although the drug has long been considered to be an effective and safe therapeutic regime against inflammatory and cardiovascular disorders, consequences of its cyclooxygenase-independent attributes on platelets, the key players in thrombogenesis, beg serious investigation. In this report we explored the effect of aspirin on platelet lifespan in murine model and its possible cytotoxicity against human platelets in vitro. Aspirin administration in mice led to significant reduction in half-life of circulating platelets, indicative of enhanced rate of platelet clearance. Aspirin-treated human platelets were found to be phagocytosed more efficiently by macrophages, associated with attenuation in platelet proteasomal activity and upregulation of conformationally active Bax, which were consistent with enhanced platelet apoptosis. Although the dosage of aspirin administered in mice was higher than the therapeutic regimen against cardiovascular events, it is comparable with the recommended anti-inflammatory prescription. Thus, above observations provide cautionary framework to critically re-evaluate prophylactic and therapeutic dosage regime of aspirin in systemic inflammatory as well as cardiovascular ailments.

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.

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.

A critical review of aspirin in the secondary prevention of noncardioembolic ischaemic stroke

Both secondary prevention (such as lifestyle modifications, pharmacotherapy or surgery) and an understanding of the influence of risk factors (including the different aetiologic mechanisms of cerebral ischaemia) play a pivotal role in reducing the burden of recurrent stroke. Regarding the types of preventative treatments available, variations exist across all clinical studies, including differences in target populations (including the type of cerebral ischaemia), risk factors, length of follow-up, drop-out rates and outcomes, which makes translating the results of clinical trials to individual patients difficult. However, with such limitations in mind, this critical albeit nonsystematic review, which compared aspirin with other antiplatelets and in combination with other drugs, showed that the benefit from aspirin treatment is consistently shown in ischaemic stroke, while harms are limited. Furthermore, no definite superiority is apparent across different antiplatelet therapies. Dual antiplatelet regimens may expose to a slight but measurable higher risk of haemorrhagic complications, perhaps in selective groups of patients (i.e. those with severe small-vessel disease or in selective racial groups). Based on our analysis, the indication of aspirin as the first-line choice, also recommended by several acknowledged international or national guidelines, may be confirmed. However, the complex nature of patients at risk of recurrent ischaemic stroke necessitates a comprehensive approach, which should be driven by the primary care physician, whose role is central to successful actions for secondary stroke prevention.

The influence of gender on the effects of aspirin in preventing myocardial infarction

BACKGROUND

There is considerable variation in the effect of aspirin therapy reducing the risk of myocardial infarction (MI). Gender could be a potential explanatory factor for the variability. We conducted a systematic review and meta-analysis to determine whether gender mix might play a role in explaining the large variation of aspirin efficacy across primary and secondary MI prevention trials.

METHODS

Randomized placebo-controlled clinical trials that examined the efficacy of aspirin therapy on MI were identified by using the PUBMED database (1966 to October 2006). Weighted linear regression technique was used to determine the relationship between log-transformed relative risk (RR) of MI and the percentage of male participants in each trial. The reciprocal of the standard error of the RR in each trial (1/SE) was used as the weight.

RESULTS

A total of 23 trials (n = 113 494 participants) were identified. Overall, compared with placebo, aspirin reduced the risk of non-fatal MI (RR = 0.72, 95% confidence interval (CI) 0.64-0.81, p < 0.001) but not of fatal MI (RR = 0.88, 95% CI 0.75-1.03, p = 0.120). A total of 27% of the variation in the non-fatal MI results could be accounted for by considering the gender mix of the trials (p = 0.017). Trials that recruited predominantly men demonstrated the largest risk reduction in non-fatal MI (RR = 0.62, 95% CI 0.54-0.71), while trials that contained predominately women failed to demonstrate a significant risk reduction in non-fatal MI (RR = 0.87, 95% CI 0.71-1.06).

CONCLUSION

Gender accounts for a substantial proportion of the variability in the efficacy of aspirin in reducing MI rates across these trials, and supports the notion that women might be less responsive to aspirin than men.

Does Prior Aspirin Use Reduce Stroke Mortality?

BACKGROUND

Millions of people around the world regularly consume aspirin, but its value in determining stroke severity is still not clear. It has been stated that prior aspirin use might reduce the severity of ischemic stroke by reducing the size of fibrin-platelet emboli or by ameliorating platelet hyperaggregability that occurs in the microcirculation. However there are only few large studies focusing on the early outcome of stroke patients including both ischemic stroke and primary intracerebral hemorrhage patients with prior aspirin therapy.

REVIEW SUMMARY

We retrospectively analyzed the medical records of 2509 consecutive stroke patients who were hospitalized in the 2nd Neurology Clinic of Haydarpaşa Numune Education and Research Hospital, Istanbul, Turkey, during the period of 1993-2003. We compared the early mortality rates in the patients with prior aspirin use versus the patients without. Of the patients without prior aspirin use, 20.1% died during the first 3 weeks of the stroke, while only 11.5% of the patients with prior aspirin use died during the same period. The difference in early mortality rate between 2 groups was extremely significant (P = 0.0008). Logistic regression analysis indicated that aspirin use was a significant (P < 0.01) and independent predictor of early stroke mortality.

CONCLUSION

Daily low dose (100-300 mg) aspirin has a protective effect in reducing the risk of early death in stroke.

Prior use of antithrombotic agents and neurological functional outcome at discharge in patients with ischemic stroke

BACKGROUND

Studies in experimental animals have suggested that antithrombotic agents may have a neuroprotective effect after an ischemic injury. The aim of this study was to analyze the effect of prior use of antithrombotic agents (antiplatelets or anticoagulants) on neurological functional outcome in patients with acute ischemic stroke.

SUBJECTS AND METHODS

Consecutive patients included in the Perugia Stroke Registry were considered for this analysis. Neurological functional outcome was evaluated at discharge using the modified Rankin Scale (mRS >or= 3 disabling stroke).

RESULTS

Of the 1921 patients included in the analysis (mean age 76.3 +/- 12.5 years; 53% males), 662 (34.5%) were on antithrombotic treatment (581 antiplatelets, 71 anticoagulants and 10 antiplatelets associated with anticoagulants). One hundred and twenty-two patients (6.4%) died in hospital; at discharge 712 patients (37.1%) were disabled and 1,087 patients (56.6%) were non-disabled. Fifty-four (44.3%) of the deceased patients and 270 (37.9%) of disabled patients were on antithrombotic treatment, while 338 (31.1%) non-disabled patients were taking antithrombotic agents. From multivariate analysis, age and stroke severity were associated with an adverse outcome. Male gender, dyslipidemia, stroke due to small vessel disease and no history of previous stroke were associated with an improved outcome, while no correlation was found between prior use of antithrombotic agents and outcome (mortality odds ratio; OR = 1.32, 95% confidence interval; CI 0.85-2.04; P = 0.20, mortality or disability OR = 0.95, 95% CI 0.72-1.25; P = 0.80).

CONCLUSION

Prior use of antithrombotic agents does not improve the functional outcome in patients with acute ischemic stroke.

Platelets in atherothrombosis

Atherosclerosis is a diffuse, systemic disease that affects the coronary, cerebral, and peripheral arterial trees. Disruption of atherosclerotic plaques leads to thrombus formation and arterial occlusion. This unpredictable and potentially life-threatening atherothrombotic sequence underlies clinical events such as angina, myocardial infarction, transient ischemic attacks, and stroke. One of the key components of a clot is the platelet. Although it was previously thought that platelets were relatively inactive cells that merely provided a framework for the attachment of other cells and proteins to mechanically stop bleeding due to injury, it is now known that this is not the case. Platelets secrete and express a large number of substances that are crucial mediators of both coagulation and inflammation. This article reviews the centrality of the platelet in atherothrombosis and briefly looks at the efficacy of antiplatelet agents in preventing and treating cardiovascular disease.

Does aspirin or other NSAIDs reduce the risk of cognitive decline in elderly persons? Results from a population-based study

OBJECTIVE

To investigate the protective effect of NSAIDs and aspirin separately on cognitive decline in elderly subjects, controlling for consistent use of these agents over a prolonged period of time.

METHODS

The study sample consisted of 1007 subjects, drawn from a population-based random sample of elderly individuals, 62-85 years old, who participated in a 3-year follow-up study. From this sample subjects were selected, who did use NSAIDs and completed all cognitive tests at both measurements (n=137), and subjects who did not use NSAIDs and completed all cognitive tests (n=475). Cognitive tests included the Mini-Mental State Examination (MMSE), tests for episodic memory (Auditory Verbal Learning Test) and information processing speed (coding task). Cognitive decline was computed using Edwards-Nunnally method. Multiple logistic regression analyses were performed to examine the association between NSAID (with and without aspirin) and decline in cognitive performance. Besides, the interaction of NSAIDs with age on cognitive decline was determined.

RESULTS

The relative risk estimates of decline in episodic memory (immediate recall) adjusted for age, gender, education, baseline MMSE, vascular diseases, diabetes mellitus and (rheumatoid) arthritis for aspirin users only was more than three times reduced (OR: 0.30, 95% CI: 0.09-0.82). The odds ratio for decline in memory of NSAID use without aspirin, adjusted for age, gender, education, baseline MMSE, vascular diseases, diabetes mellitus and (rheumatoid) arthritis was not significant (OR: 1.00, 95% CI: 0.39-2.93). The effect of aspirin was significant only in persons of 75 years and over (OR: 0.10, 95% CI: 0.01-0.81), not in subjects younger than 75 years (OR: 0.52, 95% CI: 0.14-1.96). NSAIDs did not have benefit on information processing speed. In 92% of aspirin users a low dose of 100mg daily or less was used.

CONCLUSION

Low-dose aspirin might be protective for decline in memory in individuals of 75 years and over. The benefit of a low-dose aspirin does not support an anti-inflammatory effect, but suggests an antiplatelet effect. Therefore, a possible protective effect of low-dose aspirin on cognitive decline is likely only in subjects with aspirin use over a prolonged period of time.

Aspirin and stroke prevention

According to meta-analyses aspirin provides a relative reduction in the rate of major vascular events of 19% in patients with arterial disease in general, whereas for patients with ischaemic cerebrovascular disease this reduction is only 13%. The discrepancy may well result from pathophysiological differences and not from a play of chance. There is no proven difference in efficacy according to dose. The evidence for this equivalence is most compelling in the range between 75 and 1300 mg daily, but still fairly convincing for doses between 30 and 50 mg. In contrast, side effects are clearly more frequent as the dose is higher. Other antiplatelet agents (sulfinpyrazone, ticlopidine, clopidogrel, dipyridamole, orally administered IIb/IIIa inhibitors) have no clear advantages over aspirin and in some cases definite disadvantages; the combination of aspirin and dipyridamole may be more efficacious than aspirin alone, but the evidence hinges on a single trial. If recurrent TIAs occur under treatment with aspirin, the rational response is not to change to a different antiplatelet agent, but to review the diagnosis and consider causes other than artery-to-artery embolism. Platelet aggregation can probably still occur despite complete acetylation of platelets, via pathways other than COX-1 inhibition, but in vitro aggregation tests are an unreliable measure.

Antithrombotic drugs for secondary stroke prophylaxis

Stroke is the third most common cause of adult mortality in the United States. Antithrombotic agents form the mainstay of stroke prevention. Aspirin produces a modest reduction in the risk of second stroke and is widely recommended for initial therapy. The thienopyridines ticlopidine and clopidogrel are alternatives for secondary prevention in patients who do not respond to or cannot take aspirin. They are no more effective than aspirin and have been associated with thrombotic thrombocytopenic purpura. The combination of aspirin and extended-release dipyridamole has several mechanisms of action and an additive effect on reducing stroke risk compared with either agent alone. A 2-fold increase in risk reduction and favorable safety profile suggest that the combination can serve as first-line prophylaxis against a second stroke.

Stroke: epidemiology, clinical picture, and risk factors--Part I of III

The aim of this review is to present the current knowledge regarding stroke. It will appear in three parts (in part II the pathogenesis, investigations, and prognosis will be presented, while part III will consist of the management and rehabilitation). In the current part (I) the definitions of the clinical picture are presented. These include: amaurosis fugax, vertebrobasilar transient ischemic attack, and stroke (with good recovery, in evolution and complete). The role of the following risk factors is discussed in detail: age, gender, ethnicity, heredity, hypertension, cigarette smoking, hyperlipidemia, diabetes mellitus, obesity, fibrinogen and clotting factors, oral contraceptives, erythrocytosis and hematocrit level, prior cerebrovascular and other diseases, physical inactivity, diet and alcohol consumption, illicit drug use, and genetic predisposition. In particular, regarding the carotid arteries, the following characteristics are analyzed: atheroma, carotid plaque echomorphology, carotid stenosis, presence of ulcer, local variations in surface deformability, pathological characteristics, and dissection. Finally the significance of the cerebral collateral circulation and the conditions predisposing to cardioembolism and to cerebral hemorrhage are presented.

Economic assessment of the secondary prevention of ischaemic events with lysine acetylsalicylate

OBJECTIVE

To analyse the economic benefits, in comparison with placebo, of the secondary prevention of ischaemic stroke and myocardial infarction (MI) with lysine acetylsalicylate (Kardégic) in patients with a history of ischaemic stroke, MI or stable and unstable angina pectoris.

DESIGN AND SETTING

This was a modelling study from the perspectives of direct medical costs, the social security system and society in France.

METHODS

Efficacy data for the secondary prevention of ischaemic events were derived from the Antiplatelet Trialists' Collaboration meta-analysis on antithrombotics. The rates and costs of ischaemic disease and of serious gastrointestinal adverse affects arising from long term aspirin treatment, as well as the costs of treatment with lysine acetylsalicylate, were taken from published sources, using French data where possible.

RESULTS

From the social security perspective, the estimated cost-effectiveness ratios show that the prevention of MI in patients with a history of unstable angina (with a 1-year follow-up) is a cost-saving strategy, with net benefits ranging from $US5703 (1996 prices) per avoided MI for lysine acetylsalicylate 300 mg/day to $US5761 per avoided MI for lysine acetylsalicylate 75 mg/day. The prevention of MI and stroke is also a cost-saving strategy in patients with prior MI [net benefits in a 2-year follow-up (5% discount rate) ranging from $US15 to $US494 per avoided MI and from $US37 to $US1170 per avoided stroke]. This was also true in patients with prior ischaemic stroke (net benefits in a 3-year follow-up ranging from $US610 to $US2082 per avoided MI and from $US176 to $US599 per avoided stroke). Finally, a 4-year follow-up in patients with a history of stable angina pectoris shows that prophylactic treatment with lysine acetylsalicylate is associated with net costs per avoided MI, ranging from $US4375 to $US3608 per avoided event. Sensitivity analysis confirmed that prophylaxis with lysine acetylsalicylate in patients at high risk of cardiovascular and cerebrovascular events results in savings in social security expenditure.

CONCLUSIONS

Our results underline the high economic benefit of using lysine acetylsalicylate to prevent secondary ischaemic stroke and MI in patients at high risk of cardiovascular and/or cerebrovascular events, leading to savings for the social security system and society.

Stroke prevention: anti-platelet and anti-thrombolytic therapy

In patients with TIA or ischemic stroke of noncardiac origin antiplatelet drugs are able to decrease the risk of stroke by 11-15%, and the risk of stroke, MI, and vascular death by 15-22%, but not mortality. Low doses of aspirin (50-325 mg) are as effective as high doses and cause less gastrointestinal side effects. Severe bleeding complications are not dose-dependent. The combination of aspirin with slow release dipyridamole is superior to aspirin alone for stroke prevention. Ticlopidine is superior to aspirin but has slightly more serious adverse effects (neutropenia). It will be replaced by clopidgrel which has a better safety profile. Anticoagulation with an INR between 3.0 and 4.5 is too dangerous. Whether anticoagulation with lower INR is safe and effective is not yet known.

Risk factors and outcomes for atherothrombotic disease in French patients: the RIVAGE study. RIsque VAsculaire Group d'Etude

This prospective observational study was designed to delineate the course of atherosclerotic disease in a representative group of French patients receiving standard medical care and to look for clinical and laboratory factors predictive of recurrent cardiovascular events. The 2416 study patients (75.2% men and 24.8% women) had diagnoses of peripheral arterial disease (stage II or III), ischemic heart disease (stable angina or myocardial infarction), or cerebrovascular disease (transient ischemic attack or stroke); 2004 patients (82.9%) had only one of these diagnoses, and 412 (17.1%) had more than one. Among patients with a given stage of peripheral arterial disease, mean age was older in the women than in the men. Coronary disease and cerebrovascular disease were more severe in the men. During the 18-month follow-up, 408 cardiovascular events were recorded in 380 patients (15.7% of the overall study group). In patients who had a single clinical event at inclusion, subsequent clinical events usually occurred in the same vascular bed. The incidences of coronary and cerebral events were correlated with age and the incidence of peripheral events with smoking status. Fatal events were correlated with age but not with the baseline diagnosis, except for a weak relationship with peripheral arterial disease. In a subset of 411 patients who had laboratory tests, plasma fibrinogen level was the only independent predictor of recurrence for all cardiovascular events; this parameter was more closely correlated with fatal events than with all events.

Aspirin in the prevention of strokes

Aspirin leads to a moderate but significant reduction of stroke, myocardial infarction (MI), and vascular deaths in patients with transient ischemic attack (TIA) and ischemic stroke. Low doses are as effective as high doses but are better tolerated in terms of gastro-intestinal side-effects. The recommended daily aspirin dose is therefore between 50 and 325 mg. Bleeding complications are not dose dependent and occur with the lowest doses.

Antiplatelet therapy for secondary stroke prevention

The precise role of antiplatelet therapy in secondary stroke prevention remains a matter of some debate. Although specific antiplatelet agents (notably aspirin, ticlopidine, dipyridamole, and clopidogrel) have been shown to be active in the prevention of secondary stroke, questions remain about the effective dose of these agents and their potential efficacy in combined therapeutic regimens. In addition, haematological and gastrointestinal side-effects of antiplatelet agents remain a significant clinical concern for patients and prescribing physicians. This review article examines research on both monotherapy and combination antiplatelet therapy for secondary stroke prevention, with an emphasis on lessons learned about dosage schedules, treatment protocols, and side-effect profiles.

Risk of primary intracerebral haemorrhage associated with aspirin and non-steroidal anti-inflammatory drugs: case-control study

OBJECTIVE

To examine the association between use of aspirin or other non-steroidal anti-inflammatory drugs and intracerebral haemorrhage.

DESIGN

Case-control study.

SETTING

13 major city hospitals in the Melbourne and metropolitan area.

SUBJECTS

331 consecutive cases of stroke verified by computed tomography or postmortem examination, and 331 age (+/- 5 years) and sex matched controls who were community based neighbours.

INTERVENTIONS

Questionnaire administered to all subjects either directly or by proxy with the next of kin. Drug use was validated by reviewing prescribing records held by the participants' doctors.

MAIN OUTCOME MEASURES

Previous use of aspirin or other non-steroidal anti-inflammatory drugs.

RESULTS

Univariate analysis showed no increased risk of intracerebral haemorrhage with low dose aspirin use in the preceding 2 weeks. Using multiple logistic regression to control for possible confounding factors, the odds ratio associated with the use of aspirin was 1.00 (95% confidence interval 0.60 to 1. 66, P=0.998) and the odds ratio associated with the use of other non-steroidal anti-inflammatory drugs was 0.85 (0.45 to 1.61, P=0. 611) compared with respective non-users in the preceding fortnight. Moderate to high doses of aspirin (>1225 mg/week spread over at least three doses) yielded an odds ratio of 3.05 (1.02 to 9.14, P=0. 047). There was no evidence of an increased risk among subgroups defined by age, sex, blood pressure status, alcohol intake, smoking, and the presence or absence of previous cardiovascular disease.

CONCLUSIONS

No increase in risk of intracerebral haemorrhage was found among aspirin users overall or among those who took low doses of the drug or other non-steroidal anti-inflammatory drugs. These data provide evidence that doses of aspirin usually used for prophylaxis against vascular disease produce no substantial increase in risk of intracerebral haemorrhage.

Early outcome in acute ischemic stroke is not influenced by the prophylactic use of low-dose aspirin

Aspirin reduces the occurrence of ischemic strokes. In some prophylactic trials it was suggested that aspirin might also lessen stroke severity, and hence improve outcome in patients sustaining an ischemic stroke. We examined stroke severity (by using the Mathew scale) and early outcome (Barthel index and mortality on day 21) in 91 patients with an acute (< 24 h) ischemic stroke in the territory of the middle cerebral artery. Twenty-seven patients were taking low-dose aspirin (100 or 200 mg/day) prior to their stroke, and 64 were not using antiplatelet drugs. There were no significant differences in baseline stroke severity, early (21 days) mortality or early disability between the two groups. The results of this small study suggest that the use of low-dose aspirin prior to an ischemic stroke does not influence the severity of that stroke and early outcome.

Aspirin at any dose above 30 mg offers only modest protection after cerebral ischaemia

There is continuing debate about the relative efficacy of low (< 100 mg per day), medium (300 to 325 mg per day), and high (> 900 mg per day) doses of aspirin in patients after a transient ischaemic attack or non-disabling stroke. The purpose of this study was to resolve the issue. Thus a minimeta-analysis was performed on data from 10 randomised trials of aspirin only v control treatment in 6171 patients after a transient ischaemic attack or nondisabling stroke. The data on the trials were listed in an appendix of the report on the second cycle of the Antiplatelet Trialists' Collaboration. There was virtually no difference in relative risk reduction for low, medium, and high doses of aspirin (13%, 9%, and 14% respectively). This equivalence corresponds with the results of the UK-TIA trial in a direct comparison of 300 and 1200 mg. The Dutch TIA trial showed no difference in efficacy of 30 and 283 mg. It is concluded that aspirin at any dose above 30 mg daily prevents 13% (95% confidence interval 4-21) of vascular events and that there is a need for more efficacious drugs.

Acute stroke

Disruption of cerebral blood flow may influence brain energy metabolism to produce reversible or irreversible neurologic deficits. The emergency physician is in a unique position to provide timely treatment during the first few hours of an acute stroke. He or she must be facile with unique pharmacologic and non-pharmacologic treatment designed for the stroke patient concerning ventilation, blood pressure, and circulation.

Drugs and surgery in the prevention of ischemic stroke

Randomized clinical trials have proved that warfarin therapy decreases the risk of stroke in patients with nonvalvular atrial fibrillation and in those who have had a myocardial infarction. In patients who are not candidates for long-term anticoagulant therapy, aspirin is beneficial, but the reduction in risk is smaller with aspirin than with warfarin. In patients with cerebral ischemic symptoms of noncardiac origin, aspirin and ticlopidine reduce the risk of stroke, but the benefit is modest. Given alone, neither dipyridamole nor sulfinpyrazone prevents stroke. The question remains whether either of these drugs plus aspirin is better than aspirin alone. The optimal dose of aspirin for stroke prevention has not been established. Carotid endarterectomy reduces the risk of stroke in symptomatic patients with at least 70 percent stenosis, as determined by arteriography. Current trials are addressing the question of whether endarterectomy is beneficial for patients with moderate degrees of carotid stenosis. The benefit of endarterectomy for patients with asymptomatic carotid lesions remains unclear.

Physician attitudes toward treatment options for cerebrovascular disease

One-hundred physicians older than 50 and 100 physicians younger than 50 were surveyed concerning treatment preferences for patients with transient ischemic attacks (TIAs) or completed stroke. These attitudes were compared to cardiovascular disease prevention strategies for patients with angina pectoris and myocardial infarction. Physicians younger than 50 were therapeutically aggressive for cerebrovascular and cardiovascular disease; physicians older than 50 were aggressive for cardiovascular disease but therapeutically nihilistic for cerebrovascular disease. Physicians younger than 50 were more likely to be aggressive for TIA than for completed stroke patients, and these physicians were more likely to utilize ticlopidine and oral anticoagulants for both TIA and completed stroke patients.

No effect of cloricromen on some coagulation parameters in patients with ischaemic cerebrovascular disease

Cloricromen is a new drug that inhibits platelet aggregation in man and in experimental thrombosis. Twenty patients with a history of atherothrombotic stroke received cloricromen (100 mg, twice daily) for 30 days in order to evaluate its effects on plasma fibrinogen, antithrombin III, and other variables of the haemostatic system. A statistically significant decrease in the prothrombin time (P < 0.01) was found only after 30 days of therapy. This decrease was transient and disappeared 15 days after the end of treatment. No statistically significant changes in plasma fibrinogen levels, antithrombin III, partial thromboplastin time, or platelet count were observed compared with baseline values. No side-effects were reported. This study did not reveal an effect of cloricromen on coagulative variables in patients with cerebrovascular occlusive disease.