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Aspirin for ischaemic stroke


Clinical bottom line

Early use of aspirin is of benefit in a wide range of patients after ischaemic stroke.


Z Chen et al. Indications for early aspirin use in acute ischaemic stroke. A combined analysis of 40,000 randomised patients from the Chinese acute stroke trial and the international stroke trial. Stroke 2000 31: 1240-1249.


The two trials included only patients within the first 48 hours from stroke symptom onset and randomised them to aspirin (160 or 300 mg) for four or two weeks or placebo or no treatment. One trial was blind and one open. In one trial half the patients (aspirin and control) were also given subcutaneous heparin.

Information from individual patients was collected from both trials on a range of patient characteristics and outcomes at the end of the study (average of three weeks).


Overall, allocation to aspirin produced a significant reduction in the risk of having a recurrent fatal or nonfatal ischaemic stroke of 7 per 1,000 patients treated. Against this there was an increase of 2 per 1,000 in the risk of having a haemorrhagic stroke.

Combining all bad outcomes yielded an overall risk reduction of 9 per 1,000 for the composite outcome of further stroke or death. For the composite outcome of death or dependancy the benefit was 12 per 1,000 treated.

There was a consistency of results across time from stroke onset, age, conciousness, presence or absence of atrial fibrillation, imaging findings, blood pressure and overall prognostic index. There was a somewhat larger effect in men than women.


These trials were included in the larger antiplatelets trialist collaboration analysis, and are in line with other studies showing the beneficial effects of aspirin.