Research in context
Evidence before this study
We searched PubMed with the search terms “ticagrelor”, “aspirin”, “TIA”, “minor stroke”, and “clinical trial” for reports published before Sept 1, 2016. The only published final results of a clinical trial comparing ticagrelor with aspirin in patients with transient ischaemic attack or minor ischaemic stroke were those from the Acute Stroke or Transient Ischaemic Attack Treated with Aspirin or Ticagrelor and Patient Outcomes (SOCRATES) trial. Overall, findings from the trial did not show that ticagrelor was better than aspirin for prevention of stroke, myocardial infarction, or death in patients with transient ischaemic attack and minor stroke.
Added value of this study
This prespecified exploratory analysis showed a significant treatment-by-symptomatic ipsilateral stenosis interaction, meaning that, in patients with symptomatic ipsilateral atherosclerosis stenosis, ticagrelor was better than aspirin for prevention of stroke, myocardial infarction, or death, whereas in patients without ipsilateral stenosis, ticagrelor had a neutral effect compared with aspirin. The safety profile in patients with ipsilateral stenosis, as in the overall population, was excellent. This analysis also showed that patients with symptomatic ipsilateral stenosis on aspirin have higher absolute proportions of stroke, myocardial infarction, or death than do those without ipsilateral stenosis, and that the absolute benefit of ticagrelor in individuals with ipsilateral stenosis was significantly greater.
Implications of all the available evidence
Ticagrelor has a beneficial effect in patients with atherosclerotic disease. However, patients with transient ischaemic attack or minor stroke and ipsilateral atherosclerotic stenosis are at high risk of recurrent stroke with an antiplatelet agent in monotherapy. To address this residual risk, further randomised trials with intense antiplatelet therapy (eg, dual antiplatelet therapy) should be done in patients with transient ischaemic attack or minor stroke.