VANCOUVER, BC—Early initiation of oral anticoagulation (OAC) after an acute ischemic stroke (AIS) is safe and can enhance recovery by lowering infarct volume and stroke severity, according to data from a retrospective review presented at the 68th AAN Annual Meeting.

The optimal time for starting OAC after AIS in patients with atrial fibrillation (AF) is still uncertain as earlier randomized clinical studies of oral anticoagulants have excluded patients with AIS within 7–14 days. Study authors from the Cleveland Clinic Neurological Institute, Cleveland, OH, aimed to identify patients at low risk for early initiation of OAC after AIS. They posit that the risk of initiating early OAC within 2 days carried low risk of hemorrhagic transformation in small infarcts. 

The team, led by Andrew Buletko, MD, reviewed the records of patients at the Cleveland Clinic from 2012–2014 with AIS, AF, and at least 1 follow-up visit. Early initiation was defined as starting therapy within 2 days after stroke.

A total of 100 patients with a median age of 76 years met the study criteria; 31 patients were initiated on early OAC (≤48 hours) and 53 were started on non-early OAC (median 1 day vs. 11 days). Sixteen patients did not start OAC treatment for various reasons. Researchers analyzed patient demographics, medical history, acute infarct volume, presence of hemorrhagic transformation before OAC, timing and type of oral anticoagulation therapy, and ischemic/hemorrhagic complications.

Patients who initiated OAC early had significantly lower infarct volume than the patients who initiated OAC after 2 days (median 3.35mL vs. 9.8mL; P<0.0001). Similar results were observed for stroke severity as measured by the NIH Stroke Scale (median 3 vs. 7; P<0.0001), and study authors reported less patients having hemorrhagic conversion at baseline (3% vs. 26%; P=0.0074).

At the median follow-up of 37 days, no patients experienced recurrent AIS or symptomatic hemorrhagic transformation; 1 patient had a non-CNS hemorrhage after initiating OAC.

Dr. Buletko concluded study findings suggest the early initiation of OAC within 2 days for AF patients is “safe in an appropriately selected population of AIS patients with small infarct volumes, mild stroke severity, and minimal or no hemorrhagic transformation.”