Background: Previous ischemic stroke is a predictor of recurrent ischemic stroke after an acute myocardial infarction (AMI). Dual antiplatelet therapy, including a P2Y12-inhibitor, is important in secondary prevention after AMI. Ticagrelor, a P2Y12-inhibitor, is more potent than the commonly used clopidogrel. Here, we evaluated the impact of ticagrelor on the risk of ischemic stroke following AMI in patients with previous ischemic stroke.
Methods: Data for patients with AMI that had a previous ischemic stroke were obtained from the Swedish Registry of Information and Knowledge about Swedish Heart Intensive Care Admissions. Patients were assigned to early and late cohorts, each covering a two-year time period before and after, respectively, the introduction of ticagrelor prescriptions (20 Dec 2011). Patients in the early cohort (n = 1633) were treated with clopidogrel (100%); those in the late cohort (n = 1642) were treated with either clopidogrel (66.3%) or ticagrelor (33.7%). We assessed the risk of ischemic stroke and intracranial bleeding over time with Kaplan-Meier analyses. We identified predictors of ischemic stroke with multivariable Cox regression analyses.
Results: Of 3275 patients, 311 experienced ischemic stroke after AMI. Cumulative Kaplan-Meier incidence estimates of ischemic stroke within one year after AMI were 12.1% versus 8.6% for the early and late cohorts, respectively (p<0.01). Intracranial bleeding incidences (1.2% versus 1.5%) were similar between the two cohorts.
Conclusions: Ticagrelor introduction was associated with a lower rate of ischemic stroke, with no increase in intracranial bleeding, in an AMI population with a history of ischemic stroke.