D'Anna L, Filippidis FT, Harvey K, et al. - Findings demonstrate that ischemic strokes on OAC (oral anticoagulation) represent a significant proportion of atrial fibrillation (AF)-associated strokes. Acquiring improved understanding of the causes underlying these strokes and optimizing the medical management is required.

• In this analysis of a consecutive series of patients enrolled into the EIDASAF study, a single center, observational study of ischemic stroke patients with a diagnosis AF prior to the index event, comparisons were performed between patients with oral anticoagulation therapy prior admission (OAC _prior ) vs those without anticoagulation (OAC _naïve ).

• More frequent occurrence of large and deep middle cerebral artery infarcts was seen in OAC _naïve , patients vs OAC _prior patients.

• The distribution of competing etiologies underlying stroke differed significantly between the groups.

• More frequent (re)-anticoagulation of OAC _prior at discharge was observed than OAC _naïve patients.

• Within the OAC _prior group, no difference was found between patients with recurrent strokes and those with a first stroke in terms of clinical features and pattern of cerebral infarction but the former were less frequently anticoagulated.