Medium intensity oral anticoagulants versus aspirin after cerebral ischaemia of arterial origin (ESPRIT): a randomised controlled trial. Anticoagulant vs anti-platelet therapy as prophylactic against cerebral infarction in transient ischemic attacks. A randomized trial of anticoagulants versus aspirin after cerebral ischemia of presumed arterial origin. The Stroke Prevention in Reversible Ischemia Trial (SPIRIT) Study Group. A comparison of warfarin and aspirin for the prevention of recurrent ischemic stroke. Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis. Treatment after transient ischemic attacks: a comparison between anticoagulant drug and inhibition of platelet aggregation.
Oral anticoagulants are better than aspirin for secondary prevention after myocardial infarction and after cerebral ischaemia in combination with non-rheumatic atrial fibrillation. The European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT) aimed to determine whether oral anticoagulation with medium intensity is more effective than aspirin in preventing future vascular events in patients with transient ischaemic attack or minor stroke of presumed arterial origin.
                In this international, multicentre trial, patients were randomly assigned within 6 months after a transient ischaemic attack or minor stroke of presumed arterial origin either anticoagulants (target INR range 2.0-3.0; n=536) or aspirin (30-325 mg daily; n=532). The primary outcome was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever occurred first. In a post hoc analysis anticoagulants were compared with the combination of aspirin and dipyridamole (200 mg twice daily). Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with ClinicalTrials.gov (NCT00161070).
                The anticoagulants versus aspirin comparison of ESPRIT was prematurely ended because ESPRIT reported previously that the combination of aspirin and dipyridamole was more effective than aspirin alone. Mean follow-up was 4.6 years (SD 2.2). The mean achieved INR was 2.57 (SD 0.86). A primary outcome event occurred in 99 (19%) patients on anticoagulants and in 98 (18%) patients on aspirin (hazard ratio [HR] 1.02, 95% CI 0.77-1.35). The HR for ischaemic events was 0.73 (0.52-1.01) and for major bleeding complications 2.56 (1.48-4.43). The HR for the primary outcome event comparing anticoagulants with the combination treatment of aspirin and dipyridamole was 1.31 (0.98-1.75).
                Oral anticoagulants (target INR range 2.0-3.0) are not more effective than aspirin for secondary prevention after transient ischaemic attack or minor stroke of arterial origin. A possible protective effect against ischaemic events is offset by increased bleeding complications. 156 patients with transient ischemic attacks (TIA) or reversible ischemic neurological deficit (RIND) were given prophylactic anticoagulant (AC) treatment against cerebral infarction in a prospective multicenter study from 5 hospitals in southern Sweden. After 2 months of AC treatment, 135 patients remained in the study and were randomized into 2 groups; one continued with AC treatment and one changed to anti-platelet therapy. The patients were followed for 12 months. No significant difference was seen between the 2 groups but 3 completed cerebral infarctions occurred during anti-platelet therapy against one during AC treatment. One cerebral hemorrhage was seen during AC treatment. All completed strokes occurred in men who initially had carotid symptoms. The number of patients with TIA/RIND was somewhat higher in the anti-platelet group whereas myocardial infarctions occurred more often during AC treatment. Compared to the natural history of untreated TIA/RIND both treatments were found to have a prophylactic effect against cerebral infarction. Aspirin is only modestly effective in the secondary prevention after cerebral ischemia. Studies in other vascular disorders suggest that anticoagulant drugs in patients with cerebral ischemia of presumed arterial (noncardiac) origin might be more effective. The aim of the Stroke Prevention in Reversible Ischemia Trial (SPIRIT) therefore was to compare the efficacy and safety of 30 mg aspirin daily and oral anticoagulation (international normalized ratio [INR] 3.0-4.5). Patients referred to a neurologist in one of 58 collaborating centers because of a transient ischemic attack or minor ischemic stroke (Rankin grade < or =3) were eligible. Randomization was concealed, treatment assignment was open, and assessment of outcome events was masked. The primary measure of outcome was the composite event "death from all vascular causes, nonfatal stroke, nonfatal myocardial infarction, or nonfatal major bleeding complication." The trial was stopped at the first interim analysis. A total of 1,316 patients participated; their mean follow-up was 14 months. There was an excess of the primary outcome event in the anticoagulated group (81 of 651) versus 36 of 665 in the aspirin group (hazard ratio, 2.3; 95% confidence interval [CI], 1.6-3.5). This excess could be attributed to 53 major bleeding complications (27 intracranial; 17 fatal) during anticoagulant therapy versus 6 on aspirin (3 intracranial; 1 fatal). The bleeding incidence increased by a factor of 1.43 (95% CI, 0.96-2.13) for each 0.5 unit increase of the achieved INR. Anticoagulant therapy with an INR range of 3.0 to 4.5 in patients after cerebral ischemia of presumed arterial origin is not safe. The efficacy of a lower intensity anticoagulation regimen remains to be determined. Despite the use of antiplatelet agents, usually aspirin, in patients who have had an ischemic stroke, there is still a substantial rate of recurrence. Therefore, we investigated whether warfarin, which is effective and superior to aspirin in the prevention of cardiogenic embolism, would also prove superior in the prevention of recurrent ischemic stroke in patients with a prior noncardioembolic ischemic stroke.
                In a multicenter, double-blind, randomized trial, we compared the effect of warfarin (at a dose adjusted to produce an international normalized ratio of 1.4 to 2.8) and that of aspirin (325 mg per day) on the combined primary end point of recurrent ischemic stroke or death from any cause within two years.
                The two randomized study groups were similar with respect to base-line risk factors. In the intention-to-treat analysis, no significant differences were found between the treatment groups in any of the outcomes measured. The primary end point of death or recurrent ischemic stroke was reached by 196 of 1103 patients assigned to warfarin (17.8 percent) and 176 of 1103 assigned to aspirin (16.0 percent; P=0.25; hazard ratio comparing warfarin with aspirin, 1.13; 95 percent confidence interval, 0.92 to 1.38). The rates of major hemorrhage were low (2.22 per 100 patient-years in the warfarin group and 1.49 per 100 patient-years in the aspirin group). Also, there were no significant treatment-related differences in the frequency of or time to the primary end point or major hemorrhage according to the cause of the initial stroke (1237 patients had had previous small-vessel or lacunar infarcts, 576 had had cryptogenic infarcts, and 259 had had infarcts designated as due to severe stenosis or occlusion of a large artery).
                Over two years, we found no difference between aspirin and warfarin in the prevention of recurrent ischemic stroke or death or in the rate of major hemorrhage. Consequently, we regard both warfarin and aspirin as reasonable therapeutic alternatives. Atherosclerotic intracranial arterial stenosis is an important cause of stroke. Warfarin is commonly used in preference to aspirin for this disorder, but these therapies have not been compared in a randomized trial.
                We randomly assigned patients with transient ischemic attack or stroke caused by angiographically verified 50 to 99 percent stenosis of a major intracranial artery to receive warfarin (target international normalized ratio, 2.0 to 3.0) or aspirin (1300 mg per day) in a double-blind, multicenter clinical trial. The primary end point was ischemic stroke, brain hemorrhage, or death from vascular causes other than stroke.
                After 569 patients had undergone randomization, enrollment was stopped because of concerns about the safety of the patients who had been assigned to receive warfarin. During a mean follow-up period of 1.8 years, adverse events in the two groups included death (4.3 percent in the aspirin group vs. 9.7 percent in the warfarin group; hazard ratio for aspirin relative to warfarin, 0.46; 95 percent confidence interval, 0.23 to 0.90; P=0.02), major hemorrhage (3.2 percent vs. 8.3 percent, respectively; hazard ratio, 0.39; 95 percent confidence interval, 0.18 to 0.84; P=0.01), and myocardial infarction or sudden death (2.9 percent vs. 7.3 percent, respectively; hazard ratio, 0.40; 95 percent confidence interval, 0.18 to 0.91; P=0.02). The rate of death from vascular causes was 3.2 percent in the aspirin group and 5.9 percent in the warfarin group (P=0.16); the rate of death from nonvascular causes was 1.1 percent and 3.8 percent, respectively (P=0.05). The primary end point occurred in 22.1 percent of the patients in the aspirin group and 21.8 percent of those in the warfarin group (hazard ratio, 1.04; 95 percent confidence interval, 0.73 to 1.48; P=0.83).
                Warfarin was associated with significantly higher rates of adverse events and provided no benefit over aspirin in this trial. Aspirin should be used in preference to warfarin for patients with intracranial arterial stenosis.
                Copyright 2005 Massachusetts Medical Society. Treatment with an anticoagulant (AC) or acetylsalicylic acid (ASA), chosen at random, was given to 241 patients with symptoms of carotid transient attacks of ischemia, some of whom recovered completely within 24 hours (TIA) while the others had slight residual symptoms (TIA-IR). Cerebral infarction was recorded in 4 patients in each of these treatment groups during a mean follow-up period of 20 months. The incidences of TIA and TIA-IR were also similar in the two groups. Severe hemorrhage occurred more often in the AC group, whereas other side reactions, including gastrointestinal disorders, were more common in the ASA group. Recurrent cerebral ischemic events were significantly more common among the patients that had had greater than or equal to 2 TIAs in the 14 days immediately preceding randomization, and in those with a history of CVS symptoms more than 14 days before randomization, or those with a carotid bruits. In the group experiencing greater than or equal to 2 TIAs in the 14 days prior to randomization the incidence of recurrent cerebral ischemic events was the same for the two types of treatment.