OBJECTIVE: Relevant randomized experimental and clinical studies in patients with a history of minor
stroke or TIA of noncardioembolic etiology were identified using a search of the US National Library of Medicine database, with no limits on publication dates. The primary search terms used were secondary
stroke prevention, antiplatelet
therapy,
acetylsalicylic acid, ASA,
aspirin,
aspirin + extended-release
dipyridamole, and combination
therapy.
RESULTS: Early trials of
dipyridamole monotherapy or ASA +
dipyridamole involved small numbers of patients and found no significant treatment differences. Two major trials that compared ASA monotherapy,
dipyridamole monotherapy, and ASA +
dipyridamole were identified: the Second European
Stroke Prevention Study (ESPS-2) and the European/Australasian
Stroke Prevention in Reversible Ischaemia Trial (
ESPRIT). Efficacy measurements in ESPS-2 found that
stroke relative risk reductions were 18% (P = 0.013), 16% (P = 0.039), and 37% (P < 0.001), respectively, compared with placebo for a relative risk reduction of 23.1% (P = 0.006) favoring the combination over ASA monotherapy. In
ESPRIT, patients who received ASA +
dipyridamole had a 20% relative risk reduction versus ASA monotherapy for the composite end point of death from all vascular causes, nonfatal
stroke, nonfatal
myocardial infarction, or major
bleeding complications. In ESPS-2,
headache was 5% more common with dual
therapy compared with ASA monotherapy.
ESPRIT found that combination treatment was not associated with a higher complication rate than ASA monotherapy, but that the rate of withdrawal due to adverse events was higher in the group that received the combination.
CONCLUSION: Based on the results from these 2 large, randomized trials, ASA +
dipyridamole was more effective than ASA monotherapy as first-line
therapy for secondary
stroke prevention in these patients with a history of minor
stroke or TIA of noncardioembolic etiology.