Optimal Timing of Oral Anticoagulant Therapy Initiation Post-acute Ischemic Stroke: A Narrative Review

Initiation of oral anticoagulation therapy after acute ischemic stroke requires the best trade-off between prevention of early recurrent embolic events and hemorrhagic transformation avoidance. While guidelines typically recommend starting therapy between 4 and 14 days, current evidence suggests that timing should be tailored to stroke severity, imaging findings, and individualized patient characteristics. This narrative review summarizes evidence from guidelines and clinical trials/observational studies published between 2013 and 2025, identified through PubMed, Web of Science, and Google Scholar. Summary of recent trials, including ELAN and TIMING, demonstrates that early initiation, i.e., within 48 hours to five days after minor or moderate strokes, is generally safe and associated with improved functional outcome and reduced mortality, without the risk of increased bleeding. Delayed initiation, however, is typically associated with augmented embolic events and does not provide an additional safety benefit. In general, the literature supports a patient-centered approach where early treatment is desirable for most cases, but larger infarcts, hemorrhage signs, or previous surgical procedures might call for a more cautious delay to establish stability.