When do you restart anticoagulation in patients with atrial fibrillation who just had an ischemic stroke?

The recent ELAN trial (Fischer et al., PMID 37222476) and now the published CATALYST meta-analysis (Dehbi et al., PMID 40570866) all support the concept that early anticoagulation (within 4 days of stroke) with a DOAC is safe and effective. There appears to be no interaction with clinical factors such as age or NIHSS. Early recurrent stroke, although uncommon, was reduced by a third. Caveats are that very large volume strokes were not included in the CATALYST individual patient meta-analysis. Older data from 40 years ago still support the concept that hemorrhage into an infarct bed is strongly related to the volume of infarction. However, overall these data suggest that neurologists are too cautious and can initiate anticoagulation with a DOAC much earlier than commonly taught.

The timing of when to resume anticoagulation depends on the individual aspects of the case, with infarct size being one of the main determinants. The older clinical trials showed no benefit from early anticoagulation after an acute cardioembolic ischemic stroke but an increase in the risk of hemorrhagic conversion and other bleeding. One recently published large case series (Yaghi et al., PMID 32656768) also did not show that there was a clear benefit from early use of direct oral anticoagulants, though this was not a randomized trial. In cases where the infarct is small, typically less than 1/3 of the MCA in volume, and without blood products on CT or MRI, anticoagulation will be started on discharge as a means to facilitate long term adherence. If the patient is otherwise perceived to be high risk of hemorrhagic conversion the patient returns for a follow up CT in the 2-4 week time frame to determine if there is a petechial hemorrhage and if the infarct borders are well delineated.