In a large, randomised trial, initiation of a direct oral anticoagulant within four days of stroke onset provided comparable outcomes to delayed start.

When to initiate anticoagulation after an ischaemic stroke in patients with atrial fibrillation (AF) is a common clinical question. Some guidelines suggest delayed initiation (typically 10 to 14 days after stroke onset) to minimise the risk for haemorrhagic transformation. However, the risk for brain haemorrhage is lower with direct oral anticoagulants (DOACs) than with vitamin K antagonists, and early use of DOACs could be safe. Now, investigators report on a trial that enrolled 3621 patients (mean age, 79 years; 45% women) with an ischaemic stroke and AF for whom the treating clinician was unsure about providing early (less than four days after stroke onset) or delayed initiation of DOAC therapy (seven to 14 days after onset). Clinicians could prescribe any DOAC medication.

Participants started DOAC treatment at a mean of 3.1 days in the early group and 8.3 days in the delayed group. Before starting DOAC treatment, 22% received IV thrombolysis and 7% underwent thrombectomy. At admission, 41% had an NIH stroke scale score of 0 to 4, 34% a score of 5 to 10, and 25% a score more than 10. The primary outcome – recurrent ischaemic stroke, symptomatic brain haemorrhage, unclassified stroke and systemic embolism within 90 days – was identical in the two groups (3.3%). Symptomatic intracranial haemorrhage was comparable in the two groups (0.6% early, 0.7% delayed), as was overall major bleeding (1.0% early, 1.4% delayed). Outcomes did not differ according to whether reperfusion treatment or prior anticoagulation was used.

Comment: This trial provides useful information for patients with ischaemic stroke and atrial fibrillation, showing that starting DOAC treatment within four days appears safe. The timing decision for each patient must still be individualised and take into account patient age, comorbidities and brain imaging findings.

Seemant Chaturvedi, MD, Stewart J. Greenebaum Endowed Professor of Stroke Neurology and Stroke Program Director, University of Maryland Medical System, Baltimore; Vice-Chair for Strategic Operations, Department of Neurology, University of Maryland, Baltimore, USA.

Werring D, et al. Optimal timing of anticoagulation after acute ischaemic stroke with atrial fibrillation (OPTIMAS): a multicentre, blinded-endpoint, phase 4, randomised controlled trial. Lancet 2024; 404: 1731-1741.

This summary is taken from the following Journal Watch titles: Neurology, Cardiology, General Medicine, Ambulatory Medicine, Hospital Medicine.