Furthermore, the probabilities are high that these results will dramatically alter clinical practice.

aspirin may be substantially better than aspirin alone in preventing ischemic strokes.” We emphasised that uncertainty regarding dipyridamole remains, and stated that “another trial of similar size to ESPS-2 (about 3000 patients with transient ischemic attack or stroke comparing dipyridamole combined with aspirin 325 mg to aspirin 325 mg alone) may be required to confi rm these fi ndings and dramatically alter clinical practice.” The ESPRIT Study Group has done such a trial. 4 It was an open-label controlled trial of 2739 patients with transient ischaemic attack or minor stroke randomised equally to aspirin alone or aspirin with dipyridamole (mostly extended release) and followed-up for a mean of 3·5 years. The results showed the primary outcome (the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication) was reduced by 20% (1% absolute reduction per year) in the dual therapy group. The ESPRIT Study Group did their own meta-analysis of data from previous trials and found an overall risk ratio for the composite of stroke, myocardial infarction, or vascular death of 0·82 (95%