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Objective: To compare the efficacy and safety of oral anticoagulants vs antiplatelets in patients with stroke and atherosclerotic plaques in the aortic arch or cervical or intracranial arteries, collectively described as supracardiac atherosclerosis., Methods: We searched PubMed and Scopus until August 28, 2019, for randomized trials comparing oral anticoagulants vs antiplatelets in patients with stroke and supracardiac atherosclerosis using the terms "anticoagulant or anticoagulation" and "antiplatelet or aspirin" and "randomized controlled trial or RCT" and "stroke or cerebral ischemia" and "aortic or carotid or vertebrobasilar or intracranial or atherosclerosis or stenosis or arterial." Four outcomes were assessed: recurrent ischemic stroke, major ischemic event or death, major bleeding, and intracranial bleeding. Treatment effects (relative risk [RR] and 95% confidence interval [CI]) were estimated by meta-analysis using random-effects models., Results: Among 1,117 articles identified in the literature search, results from 10 randomized controlled trials involving 6,068 patients with stroke/TIA with supracardiac atherosclerosis were included in the meta-analysis. Recurrent ischemic stroke rates were 2.94 per 100 patient-years in the anticoagulant-assigned patients vs 3.30 per 100 patient-years in the antiplatelet-assigned patients (RR, 0.91; 95% CI, 0.70-1.18 for the SJ estimator, I 2 = 26%). Major ischemic event or death rates were 4.39 per 100 patient-years in anticoagulant-assigned patients vs 4.32 in antiplatelet-assigned patients (RR, 1.03; 95% CI, 0.79-1.35; I 2 = 54.5%). Major bleeding rates were 2.88 per 100 patient-years in anticoagulant-assigned patients vs 0.82 in antiplatelet-assigned patients (RR, 3.21; 95% CI, 1.96-5.24; I 2 = 46%)., Conclusion: This systematic review and meta-analysis showed that anticoagulant-assigned patients with stroke and supracardiac atherosclerosis were not at different risk of ischemic stroke recurrence and increased risk of major bleeding compared to antiplatelet-assigned patients., (© 2020 American Academy of Neurology.)

Background and Purpose- Emboli in embolic stroke of undetermined source (ESUS) may originate from various potential embolic sources (PES), some of which may respond better to anticoagulation, whereas others to antiplatelets. We analyzed whether rivaroxaban is associated with reduction of recurrent stroke compared with aspirin in patients with ESUS across different PES and by number of PES. Methods- We assessed the presence/absence of each PES (atrial cardiopathy, atrial fibrillation, arterial atherosclerosis, left ventricular dysfunction, cardiac valvulopathy, patent foramen ovale, cancer) in NAVIGATE-ESUS (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source) participants. Prevalence of each PES, as well as treatment effect and risk of event for each PES were determined. Results by number of PES were also determined. The outcomes were ischemic stroke, all-cause mortality, cardiovascular mortality, and myocardial infarction. Results- In 7213 patients (38% women, mean age 67years) followed for a median of 11 months, the 3 most prevalent PES were atrial cardiopathy (37%), left ventricular disease (36%), and arterial atherosclerosis (29%). Forty-one percent of all patients had multiple PES, with 15% having ≥3 PES. None or a single PES was present in 23% and 36%, respectively. Recurrent ischemic stroke risk was similar for rivaroxaban- and aspirin-assigned patients for each PES, except for those with cardiac valvular disease which was marginally higher in rivaroxaban-assigned patients (hazard ratio, 1.8 [95% CI, 1.0-3.0]). All-cause mortality risks were similar across treatment groups for each PES while too few myocardial infarctions and cardiovascular deaths occurred for meaningful assessment. Increasing number of PES was not associated with increased stroke recurrence nor all-cause mortality, and outcomes did not vary between rivaroxaban- and aspirin-assigned patients by number of PES. Conclusions- A large proportion of patients with ESUS had multiple PES which could explain the neutral results of NAVIGATE-ESUS. Recurrence rates between rivaroxaban- and aspirin-assigned patients were similar across the spectrum of PES. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02313909.

Background and Purpose: Subdural hematomas are an important bleeding complication of anticoagulation. We quantify the risk of subdural hematoma associated with anticoagulation with vitamin K antagonists (VKAs) compared with other oral antithrombotic therapies., Methods: Randomized trials were identified from the Cochrane Central Register of Controlled Trials and were included if published since 1980 and compared oral VKAs with antiplatelet therapy or with direct-acting oral anticoagulants. Two reviewers independently extracted data with differences resolved by joint review., Results: Nineteen randomized trials were included that involved 92 156 patients and 275 subdural hematomas. By meta-analysis, VKAs were associated with a significantly increased risk of subdural hematoma (odds ratios, 3.0; 95% confidence interval, 1.5-6.1) compared with antiplatelet therapy (9 trials, 11 603 participants). The risk of subdural hematoma was also significantly higher with VKAs versus factor Xa inhibitors (meta-analysis odds ratios, 2.9; 95% confidence interval, 2.1-4.1; 5 trials, 49 687 patients) and direct thrombin inhibitors (meta-analysis odds ratios, 1.8; 95% confidence interval, 1.2-2.7; 5 trials, 30 866 patients) versus VKAs. The absolute rate of subdural hematoma among 24 485 patients with atrial fibrillation treated with VKAs pooled from 6 trials testing direct-acting oral anticoagulants was 2.9 (95% confidence interval, 2.5-3.5) per 1000 patient-years., Conclusions: VKA use significantly increases the risk of subdural hematoma by ≈3-fold relative to antiplatelet therapy. Direct-acting oral anticoagulants are associated with a significantly reduced risk of subdural hematomas versus VKAs. Based on indirect comparisons to VKAs, the risks of subdural hematoma are similar with antiplatelet monotherapies and factor Xa inhibitors., (© 2014 American Heart Association, Inc.)

Background and Objectives: The efficacy of adjusted-dose warfarin for prevention of stroke in atrial fibrillation patients with stage 3 chronic kidney disease (CKD) is unknown., Design, Setting, Participants, & Measurements: Patients with stage 3 CKD participating in the Stroke Prevention in Atrial Fibrillation 3 trials were assessed to determine the effect of warfarin anticoagulation on stroke and major hemorrhage, and whether CKD status independently contributed to stroke risk. High-risk participants (n = 1044) in the randomized trial were assigned to adjusted-dose warfarin (target international normalized ratio 2 to 3) versus aspirin (325 mg) plus fixed, low-dose warfarin (subsequently shown to be equivalent to aspirin alone). Low-risk participants (n = 892) all received 325 mg aspirin daily. The primary outcome was ischemic stroke (96%) or systemic embolism (4%)., Results: Among the 1936 participants in the two trials, 42% (n = 805) had stage 3 CKD at entry. Considering the 1314 patients not assigned to adjusted-dose warfarin, the primary event rate was double among those with stage 3 CKD (hazard ratio 2.0, 95% CI 1.2, 3.3) versus those with a higher estimated GFR (eGFR). Among the 516 participants with stage 3 CKD included in the randomized trial, ischemic stroke/systemic embolism was reduced 76% (95% CI 42, 90; P < 0.001) by adjusted-dose warfarin compared with aspirin/low-dose warfarin; there was no difference in major hemorrhage (5 patients versus 6 patients, respectively)., Conclusions: Among atrial fibrillation patients participating in the Stroke Prevention in Atrial Fibrillation III trials, stage 3 CKD was associated with higher rates of ischemic stroke/systemic embolism. Adjusted-dose warfarin markedly reduced ischemic stroke/systemic embolism in high-risk atrial fibrillation patients with stage 3 CKD.

Background: Non-valvular atrial fibrillation (AF) carries an increased risk of stroke mediated by embolism of stasis-precipitated thrombi originating in the left atrial appendage. Both oral anticoagulants and antiplatelet agents have proven effective for stroke prevention in most patients at high risk for vascular events, but primary stroke prevention in patients with non-valvular AF potentially merits separate consideration because of the suspected cardio-embolic mechanism of most strokes in AF patients., Objectives: To characterize the relative effect of long-term oral anticoagulant treatment compared with antiplatelet therapy on major vascular events in patients with non-valvular AF and no history of stroke or transient ischemic attack (TIA)., Search Strategy: We searched the Cochrane Stroke Group Trials Register (June 2006). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006), MEDLINE (1966 to June 2006) and EMBASE (1980 to June 2006). We contacted the Atrial Fibrillation Collaboration and experts working in the field to identify unpublished and ongoing trials., Selection Criteria: All unconfounded, randomized trials in which long-term (more than four weeks) adjusted-dose oral anticoagulant treatment was compared with antiplatelet therapy in patients with chronic non-valvular AF., Data Collection and Analysis: Two review authors independently selected trials for inclusion, assessed quality and extracted data. The Peto method was used for combining odds ratios after assessing for heterogeneity., Main Results: Eight randomized trials, including 9598 patients, tested adjusted-dose warfarin versus aspirin (in dosages ranging from 75 to 325 mg/day) in AF patients without prior stroke or TIA. The mean overall follow up was 1.9 years/participant. Oral anticoagulants were associated with lower risk of all stroke (odds ratio (OR) 0.68, 95% confidence interval (CI) 0.54 to 0.85), ischemic stroke (OR 0.53, 95% CI 0.41 to 0.68) and systemic emboli (OR 0.48, 95% CI 0.25 to 0.90). All disabling or fatal strokes (OR 0.71, 95% CI 0.59 to 1.04) and myocardial infarction (OR 0.69, 95% CI 0.47 to 1.01) were substantially but not significantly reduced by oral anticoagulants. Vascular death (OR 0.93, 95% CI 0.75 to 1.15) and all cause mortality (OR 0.99, 95% CI 0.83 to 1.18), were similar with these treatments. Intracranial hemorrhages (OR 1.98, 95% CI 1.20 to 3.28) were increased by oral anticoagulant therapy., Authors' Conclusions: Adjusted-dose warfarin and related oral anticoagulants reduce stroke, disabling stroke and other major vascular events for those with non-valvular AF by about one third when compared with antiplatelet therapy.

Purpose: The risk of ischemic stroke varies widely among patients with nonvalvular atrial fibrillation, influencing the choice of prophylactic antithrombotic therapy. We assessed three schemes for stroke risk stratification in these patients who were treated with aspirin and who did not have prior cerebral ischemia., Subjects and Methods: Criteria from three schemes of risk stratification were applied to a longitudinally observed cohort of patients with atrial fibrillation who did not have prior cerebral ischemia and who were treated with aspirin alone or aspirin combined with low, ineffective doses of warfarin in a multicenter clinical trial. The ability of the schemes to identify patients at high (>/=6%), low (75 years old as high risk (observed stroke rate 4.2 per 100 person-years), while the remaining scheme classified one third of patients in this age group as low risk (observed stroke rate 0.6 per 100 person-years)., Conclusions: When tested in a large cohort of patients with atrial fibrillation who were treated with aspirin, available risk-stratification schemes successfully identified patients with low rates of ischemic stroke, but less consistently identified high-risk patients.

Purpose: To characterize the efficacy and safety of anticoagulants and antiplatelet agents for prevention of stroke in patients with atrial fibrillation., Data Sources: Randomized trials identified by using the search strategy developed by the Cochrane Collaboration Stroke Review Group., Study Selection: All published randomized trials testing antithrombotic agents to prevent stroke in patients with atrial fibrillation., Data Extraction: Data on interventions, number of participants, duration of exposure and occurrence of all stroke (ischemic and hemorrhagic), major extracranial bleeding, and death were extracted independently by two investigators., Data Synthesis: Sixteen trials included a total of 9874 participants (mean follow-up, 1.7 years). Adjusted-dose warfarin (six trials, 2900 participants) reduced stroke by 62% (95% CI, 48% to 72%); absolute risk reductions were 2.7% per year for primary prevention and 8.4% per year for secondary prevention. Major extracranial bleeding was increased by warfarin therapy (absolute risk increase, 0.3% per year). Aspirin (six trials, 3119 participants) reduced stroke by 22% (CI, 2% to 38%); absolute risk reductions were 1.5% per year for primary prevention and 2.5% per year for secondary prevention. Adjusted-dose warfarin (five trials, 2837 participants) was more efficacious than aspirin (relative risk reduction, 36% [CI, 14% to 52%]). Other randomized comparisons yielded inconclusive results., Conclusions: Adjusted-dose warfarin and aspirin reduce stroke in patients with atrial fibrillation, and warfarin is substantially more efficacious than aspirin. The benefit of antithrombotic therapy was not offset by the occurrence of major hemorrhage among participants in randomized trials. Judicious use of antithrombotic therapy, tailored according to the inherent risk for stroke, importantly reduces stroke in patients with atrial fibrillation.

Background and Purpose: Nonvalvular atrial fibrillation (AF) is a strong, independent risk factor for stroke, but the absolute rate of stroke varies widely among AF patients, importantly influencing the potential benefit of antithrombotic prophylaxis. We explore factors associated with ischemic stroke in AF patients taking aspirin., Methods: We performed multivariate logistic regression analysis of 2012 participants given aspirin alone or in combination with low, inefficacious doses of warfarin in the Stroke Prevention in Atrial Fibrillation I-III trials followed for a mean of 2.0 years, during which 130 ischemic strokes were observed., Results: Age (relative risk [RR]=1.8 per decade, P<0.001), female sex (RR=1.6, P=0.01), history of hypertension (RR=2.0, P<0.001), systolic blood pressure >160 mm Hg (RR=2.3, P<0.001), and prior stroke or transient ischemic attack (RR=2.9, P<0.001) were independently associated with increased stroke risk. Regular consumption of >/=14 alcohol-containing drinks per week was associated with reduced stroke risk (adjusted RR=0.4, P=0.04). Among SPAF III participants, estrogen hormone replacement therapy was associated with a higher risk of ischemic stroke (adjusted RR=3.2, P=0.007). With the use of these variables, a risk stratification scheme for primary prevention separated participants into those with high (7.1%/y, 22% of the cohort), moderate (2.6%/y, 37% of the cohort), and low (0.9%/y, 41% of the cohort) rates of stroke. Ischemic strokes in low-risk participants were less often disabling (P<0.001)., Conclusions: Patients with AF who have high and low rates of stroke during treatment with aspirin can be identified. However, validation of our risk stratification scheme is necessary before it can be applied with confidence to clinical management. Postmenopausal estrogen replacement therapy and moderate alcohol consumption may additionally modify the risk of stroke in AF, but these findings require confirmation.

Patients with atrial fibrillation and with documented aortic plaque who were assigned to adjusted-dose warfarin therapy (international normalized ratio 2.0 to 3.0) had an annual rate of cholesterol embolization of 0.7% (95% confidence interval [CI] 0.1% to 5.3%/patient-year). Warfarin-assigned patients with plaque had a lower rate of embolic events (5.9%/year; 95% CI 3.0 to 12) than those on combination low-dose warfarin (international normalized ratio <1.5) plus aspirin (17.3%/year; 95% CI 11 to 27; p = 0.01).