Stroke phenotype may aid antiplatelet treatment choice in ischemic stroke patients
medwireNews: Patients with ischemic stroke or transient ischemic attack of atherosclerotic origin may gain more benefit from taking ticagrelor than aspirin, study findings in The Lancet Neurology indicate.
The results are concluded from a prespecified exploratory analysis of data from the SOCRATES trial, which found a significant interaction, with a p value of 0.017, for the effect of ticagrelor versus aspirin in preventing stroke, myocardial infarction, or death in patients with transient ischemic attack or minor stroke if the patient had symptomatic ipsilateral atherosclerosis stenosis.
“The interaction that we found in this exploratory analysis suggests that future trials of antiplatelet treatment should target patients with atherosclerotic stenosis,” say Pierre Amarenco (Bichat University Hospital, Paris, France).
The main trial findings published in 2016 failed to show a significant difference between ticagrelor (180 mg loading dose followed by 90 mg twice daily for 89 days) and aspirin (300 mg loading dose followed by 100 mg/day for 89 days) for the composite primary endpoint of stroke, myocardial infarction, or death within 90 days in the participants overall.
But among 3081 (23.3%) of the 13,199 randomly allocated patients with potentially causal atherosclerotic disease, determined according to ASCOD grading A1 and A2, the 1542 individuals taking ticagrelor had a significantly lower incidence of the primary endpoint than the 1539 taking aspirin, at 6.7% versus 9.6%. This gave a relative risk reduction of 32%.
By contrast, there was no significant treatment effect among the 10,118 patients without ipsilateral atherosclerosis stenosis. The incidence of the combined endpoint was 6.7% among the 5047 patients taking ticagrelor and 6.9% among the 5071 taking aspirin.
The researchers estimate that the patients with symptomatic ipsilateral stenosis who took aspirin had the highest proportion of primary endpoint events, at 9.4%. This compared with 6.8% among those without ipsilateral extracranial or intracranial stenosis not taking aspirin.
“This finding is concordant with those from previous studies suggesting that atherosclerotic disease carries a greater risk than do other stroke subtypes in patients with transient ischaemic attack or minor ischaemic stoke,” the team comments.
The authors believe that their research “provides empirical evidence of the importance of an understanding of the stroke mechanism and cause in the approach to early stroke prevention treatments.”
By Lucy Piper
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