Dipyridamole And Acetylsalicylic Acid (Asa) In The Secondary Prevention Of Vascular Events After Stroke Or Tia

The results of the Second European Stroke Prevention Study (ESPS-2), a trial on the efficacy of low-dose acetylsalicylic acid (ASA), modified-release dipyridamole (DP), and the two agents in combination for the secondary prevention of ischaemic stroke, have recently become available.We reviewed these findings in the light of the findings of earlier randomised trials of prolonged treatment with ASA, DP or their combination in patients with a past history of stroke or transient ischaemic attack(TIA). We used data on the occurrence of vascular events from the report of the Antiplatelets Trialists' Collaboration, and calculated overall relative risk reductions.The relative risk reduction for ASA Versus placebo was 13% and there was no indication of a dose-effect relationship. The addition of DP to low-dose ASA further reduced the risk of vascular events by 15%. All trials (including ESPS-2) together show that the protective effects of DP and ASA in the secondary prevention of stroke are additive. The overall evidence for the efficacy of the combination Versus ASA alone now favours the combination.