OPTIMAS: A randomised controlled trial to establish the optimal timing of anticoagulation after acute ischaemic Stroke

ABSTRACT

Introduction: Atrial fibrillation (AF) causes about one-fifth of ischaemic strokes, with a high risk of early recurrence. Oral anticoagulation is highly effective for reducing the long-term risk of recurrent ischaemic stroke in patients with AF. However, its benefit in the acute phase is unclear. OPTIMAS is an RCT aiming to establish the safety and efficacy of early anticoagulation with a direct oral anticoagulant (DOAC). Available evidence and guidelines emphasise the lack of evidence to guide clinicians and support continued randomisation into trials including OPTIMAS. Method(s) OPTIMAS will enrol 3,478 participants with ischaemic stroke and AF from 100+ stroke services in the UK. Participants are randomised 11 to early (within 4 days) or standard (day 7 to 14 after stroke) initiation of anticoagulation. Follow-up is at 90 days, blinded to treatment allocation. The primary outcome is the incidence of stroke of any cause, and systemic arterial embolism. Result(s) OPTIMAS opened in June 2019 and is recruiting from 95 sites. 2,053 participants have been randomised as of 29th June 2022. Recruitment and site-set up were reduced during the COVID-19 pandemic, due to national lockdowns and hospital staff being reallocated to COVID-related trials. This did temporarily slow recruitment, but we rapidly developed a successful contingency plan to face these challenges, implementing strategies including collecting the 90-day follow-ups centrally;obtaining consents by phone;and encouraging sites to sign up to the NIHR Associate PI Scheme to help with trial-related activities. For the last 10 months the trial has consistently been recruiting at least 80 participants per month. Conclusion(s) OPTIMAS will determine the efficacy and safety of early anticoagulation in patients with ischaemic strokes and AF. The trial recruited successfully during the most challenging period of the COVID- 19 pandemic and continues to do so.