Network meta-analysis: simultaneous meta-analysis of common antiplatelet regimens after transient ischaemic attack or stroke.

Network meta-analysis can provide estimates of treatment efficacy of multiple treatment regimens, even when direct comparisons are unavailable. We used network meta-analysis to compare commonly used antiplatelet regimens in the prevention of serious vascular events after transient ischaemic attack (TIA) or stroke. We performed direct meta-analyses of randomized, controlled trials evaluating antiplatelet agents after TIA or stroke. We chose the endpoint stroke, myocardial infarction, and vascular death. Network meta-analysis was then used to estimate the relative efficacy of the various antiplatelet regimens. Twenty-four trials involving 42688 TIA or stroke patients who suffered 6830 serious vascular events were included. In the network meta-analysis, all antiplatelet regimens (aspirin, aspirin plus dipyridamole, thienopyridines, and combination of aspirin and thienopyridines) were significantly more effective than placebo. The combination of aspirin and dipyridamole was more effective than thienopyridines (OR, 0.84; 95% CI, 0.73-0.97) and more effective than aspirin (OR, 0.78; 95% CI, 0.70-0.87). Our analysis suggests that the most powerful antiplatelet regimen in the prevention of serious vascular events after TIA or stroke is the combination of aspirin and dipyridamole. Network meta-analysis could be used to synthesize accumulating evidence from clinical trials in a broad range of vascular disorders.