To review the risk of hemorrhagic conversion of ischemic stroke in patients with underlying atrial fibrillation based on stroke volume and time of initiation of therapeutic anticoagulation (AC).

The mainstay of secondary stroke prevention in the setting of underlying atrial fibrillation is anti-coagulation. However, after a large acute ischemic stroke, the concerns for hemorrhagic transformation are thought to outweigh the benefits of resuming or initiating anti-coagulation often resulting in a significant delay in treatment. There is paucity of data to guide Neurologists in adequately assessing the risk to benefit ratio of anti-coagulation in this setting. Currently, there is a variation in clinical practice and most expert opinions suggest initiating anti-coagulation within 14 days of stroke. 

We performed a retrospective chart analysis of patients discharged from Stony Brook University Hospital during the calendar years 2013 - 2017 with the diagnoses of both ischemic stroke and atrial fibrillation. Patients started on DOACs as well as Vitamin K antagonists were included. We assessed the cerebral infarct volume through manual selection of hyperintense lesions on diffusion weighted image MRI sequences followed by semi-automated volume segmentation and measurement using Olea Sphere version 3.0 volumetric analysis software.

Out of the first 200 charts reviewed, 112 patients qualified for the study. Anti-coagulation was started on 67 patients in the first 2 days after stroke, 17 had AC initiated on days 3-5, 7 on days 6-7, 10 on days 7-14, and 11 after day 14. The stroke volumes ranged from 0.09 ml to 160.33 ml. There were no incidences of symptomatic hemorrhagic conversions and none of the patients had recurrent stroke while waiting to be started on AC.