Increased Use of Ticagrelor After Myocardial Infarction Is Not Associated With Intracranial Hemorrhage.

Abstract

Background and Purpose- Guidelines recommend dual antiplatelet treatment with ticagrelor instead of clopidogrel after acute myocardial infarction. Ticagrelor increases major and minor noncoronary artery bypass graft bleeding compared with clopidogrel, but whether the risk of intracranial hemorrhage (ICH) increases is unknown. We aimed to examine any association between ticagrelor and ICH and to identify predictors of ICH among unselected patients after acute myocardial infarction. Methods- Patients with acute myocardial infarction were identified using the Register of Information and Knowledge About Swedish Heart Intensive Care Admissions, and the data were combined with the Swedish National Patient Registry to identify ICH occurrence. To avoid obvious selection bias related to the choice of dual antiplatelet treatment, we divided the study cohorts into 2 time periods of similar length using the first prescription of ticagrelor as a cutoff point (December 20, 2011). The risk of ICH during the first period (100% clopidogrel treatment) versus the second period (52.1% ticagrelor and 47.8% clopidogrel treatment) was assessed using Kaplan-Meier analysis. Cox proportional-hazards regression analyses, with assessment of interactions between all significant variables, were used to identify predictors of ICH. Results- The analysis included 47 674 patients with acute myocardial infarction. The cumulative incidence of ICH during the first period was 0.59% (91 cases [95% CI, 0.49-0.69]) versus 0.52% (97 cases [95% CI, 0.43-0.61]) during the second period ( P=0.83). In multivariable Cox analysis, study period (second versus first period) was not predictive of ICH. Interaction analyses showed that age and prior cardiovascular morbidities were of importance in predicting the risk of ICH. Conclusions- The increased use of ticagrelor was not associated with ICH, whereas age and prior cardiovascular morbidities were related to the risk of ICH and interacted significantly.