ABSTRACT
Oral anticoagulation (OAC) prevents stroke in atrial fibrillation, yet a residual stroke risk remains. In this single-center retrospective analysis of acute ischemic stroke patients despite OAC, suboptimal OAC treatment is common (30%: inappropriate dosing (17%); patient non-adherence (13%)). Other causes of stroke included OAC interruption (14.5%), a competing stroke mechanism (11.0%), and undetermined breakthrough stroke in 44.5%. Overall, easily modifiable causes of ischemic stroke despite OAC are common. Accordingly, strategies to improve treatment compliance, including appropriate dosing along with guideline-based risk factor and periprocedural OAC management, should be emphasized to improve secondary stroke prevention in this patient population.