It is unknown whether dual antiplatelet therapy with ticagrelor instead of clopidogrel reduces the risk of ischaemic stroke in acute myocardial infarction patients that undergo percutaneous coronary intervention. This study investigated whether the introduction of dual antiplatelet therapy with ticagrelor was associated with reduced ischaemic stroke risk in a real-world population.Methods and results
Patients with ischaemic stroke after acute myocardial infarction from 8 December 2009–31 December 2013 were identified using the Register for Information and Knowledge on Swedish Heart Intensive Care Admissions and the Swedish National Patient Register. The study period was divided into two similar periods using the date of the first prescription of ticagrelor as the cut-off. The risk of ischaemic stroke in percutaneous coronary intervention-treated acute myocardial infarction patients during the first period (100% clopidogrel treatment) versus the second period (60.7% ticagrelor treatment) was assessed using Kaplan-Meier analysis. Variables associated with ischaemic stroke were identified using a multivariable Cox proportional hazards model. There were 686 ischaemic stroke events (2.0%) among 34931 percutaneous coronary intervention-treated acute myocardial infarction patients within one year, 366 (2.2%) during the first period and 320 (1.8%) during the second period (p = 0.004). The Cox model showed a 21% relative risk reduction in ischaemic stroke in the second period versus the first one (hazard ratio 0.79, 95% confidence interval, 0.68–0.92; p = 0.003). The independent predictors of increased stroke risk were older age, hypertension, diabetes mellitus, atrial fibrillation, heart failure during hospitalization, previous ischaemic stroke, and ST-segment elevation myocardial infarction.Conclusion
The risk of ischaemic stroke in percutaneous coronary intervention-treated acute myocardial infarction patients decreased after the introduction of ticagrelor in Sweden.