Aspirin is widely used for the prevention of recurrent stroke in patients with transient ischaemic attack (TIA) of arterial origin, because it is effective and inexpensive. Clopidogrel and the combination of aspirin and extended-release dipyridamole are more effective than aspirin, but are also much more expensive. No other antithrombotic regimens provide significant advantages over aspirin, although cilostazol and the novel platelet protease-activated receptor-1 antagonist, SCH 530348, are currently being evaluated.
Numerous trials have examined the efficacy of antiplatelet drugs, primarily aspirin for prevention of vascular events in patients with a prior TIA or stroke. Although many were small and inconclusive, the Antiplatelet Trialists’ Collaboration (ATC) individual patient data meta-analysis reported that among more than 23000 patients (from 21 randomized controlled trials), antiplatelet therapy (usually aspirin) compared with placebo or untreated control continued for a mean of 29 months was associated with a 22% reduction in the odds of recurrent ischemic stroke, myocardial infarction (MI), or vascular death (17.8% versus 21.4%, P=0.001).