News: Two trials survey optimal timeline of DOAC initiation after stroke in AF

The long-standing debate as to when to start anticoagulation in such patients appears to be settled, Medscape Medical News reported.

Initiation of a direct oral anticoagulant (DOAC) within four days after ischemic stroke associated with atrial fibrillation (AF) had no worse outcome than delayed initiation (seven to 14 days), according to results published in The Lancet of a trial called OPTIMAS. For both, researchers analyzed the potential outcome of ischemic stroke, intracranial hemorrhage, unclassifiable stroke, or systemic embolism at 90 days. Furthermore, results of the OPTIMAS trial showed that early DOAC initiation was safe with a low rate of symptomatic hemorrhage regardless of stroke severity.

The OPTIMAS trial used a broad population of patients with acute ischemic stroke associated with AF, including patient subgroups for which there are concerns about early oral anticoagulation: who have had a moderate to severe stroke, have hemorrhagic transformation (with the exception of parenchymal hematoma type 2), or are already taking oral anticoagulants. Results showed that the primary outcome occurred in 3.3% of both the early and later groups, establishing noninferiority between the two timelines.

Also, a new meta-analysis known as CATALYST showed a clear benefit of earlier initiation (within four days) versus later (five days and up) when looking at the primary outcome of new ischemic stroke, symptomatic intracerebral hemorrhage, or unclassified stroke at 30 days. The analysis included all four randomized trials now available on this issue, namely, TIMING, ELAN, OPTIMAS, and START. According to their results, 2.12% of the early-initiated group had a primary outcome, compared to a slightly higher rate of 3.02% of the later-initiated group.

“When to start anticoagulation in acute ischemic stroke patients with AF has been uncertain for a long time,” said Craig Anderson, MD, The George Institute for Global Health, Sydney, Australia, chair of the 2024 World Stroke Congress where the OPTIMAS trial results were presented. “The dogma has always been that we should wait. Over the years, we’ve become a little bit more confident, but now we’ve got good data from randomized trials showing that early initiation is safe, with the meta-analysis showing benefit.”

Anderson did caution that there still may be concerns about starting DOACs early in some groups, however, including Asian populations that have a higher bleeding risk (these trials included predominantly white patients) and people who are older or frail, who may have extensive small vessel disease.

Editor’s note: To read Medscape Medical News’ coverage of this story, click here. To read The Lancet study, click here.