Ischemic stroke in oral anticoagulated patients with atrial fibrillation.

Background: Ischemic strokes in orally anticoagulated patients pose challenges for acute management and secondary prevention but the characteristics of these strokes are poorly understood. We examined the clinical and imaging features, the presumed underlying etiology and the subsequent antithrombotic management. Methods: We analyzed a consecutive series of patients enrolled into the EIDASAF study, a single center, observational study of ischemic stroke patients with a diagnosis atrial fibrillation (AF) prior to the index event who had been admitted to the Hyperacute Stroke Unit of Imperial College London between 2010 and 2017. We compared patients with oral anticoagulation therapy prior admission (OACprior) with those without anticoagulation (OACnaive). Brain imaging was analyzed centrally. Results: 763 patients were included in the analysis. 481 (63%) were OACnaive while 282 (37%) were OACprior. Patients with OACprior were younger, more often had a previous history of stroke or transient ischemic attack (TIA), and more often suffered from hypertension and diabetes. In OACnaive, patients, large and deep middle cerebral artery infarcts occurred more often than in OACprior patients. The groups differed significantly in the distribution of competing etiologies underlying their stroke. At discharge, OACprior more frequently were (re)‐anticoagulated compared to OACnaive patients. Within the OACprior group, patients with recurrent strokes did not differ from those with a first stroke regarding clinical characteristics and pattern of cerebral infarction but they were less frequently anticoagulated. Conclusions: Ischemic strokes on OAC represent a significant proportion of AF‐related strokes. There is an unmet need to better understand the causes underlying these strokes and to optimize the medical management. [ABSTRACT FROM AUTHOR]