Early anticoagulation in patients with stroke and atrial fibrillation is associated with fewer ischaemic lesions at 1 month: the ATTUNE study

Background The optimal time to commence anticoagulation in patients with atrial fibrillation(AF)after ischaemic stroke or transient ischaemic attack(TIA)is unclear,with guidelines differing in recommendations.A limitation of previous studies is the focus on clinically overt stroke,rather than radiologically obvious diffusion-weighted imaging ischaemic lesions.We aimed to quantify silent ischaemic lesions and haemorrhages on MRI at 1month in patients commenced on early(<4days)vs late(≥4days)anticoagulation.We hypothesised that there would be fewer ischaemic lesions and more haemorrhages in the early anticoagulant group at 1-month MRI.Methods A prospective multicentre,observational cohort study was performed at 11 Australian stroke centres.Clinical and MRI data were collected at baseline and follow-up,with blinded imaging assessment performed by two authors.Timing of commencement of anticoagulation was at the discretion of the treating stroke physician.Results We recruited 276 patients of whom 208 met the eligibility criteria.The average age was 74.2 years(SD±10.63),and 79(38%)patients were female.Median National Institute of Health Stroke Scale score was 5(IQR 1–12).Median baseline ischaemic lesion volume was 5mL(IQR 2–17).There were a greater number of new ischaemic lesions on follow-up MRI in patients commenced on anticoagulation≥4days after index event(17%vs 8%,p=0.04),but no difference in haemorrhage rates(22%vs 32%,p=0.10).Baseline ischaemic lesion volume of≤5mL was less likely to have a new haemorrhage at 1month(p=0.02).There was no difference in haemorrhage rates in patients with an initial ischaemic lesion volume of>5mL,regardless of anticoagulation timing.Conclusion Commencing anticoagulation<4days after stroke or TIA is associated with fewer ischaemic lesions at 1month in AF patients.There is no increased rate of haemorrhage with early anticoagulation.These results suggest that early anticoagulation after mild-to-moderate acute ischaemic stroke associated with AF might be safe,but randomised controlled studies are needed to inform clinical practice.WHAT IS ALREADY KNOWN ON THIS TOPIC⇒Early anticoagulation after ischaemic stroke associ-ated with atrial fibrillation(AF)may reduce the rate of recurrent diffusion-weighted imaging ischaemic lesions and increase the rate of new haemorrhage.⇒It is unknown whether early anticoagulation also re-duces the rate of new silent ischaemic lesions.WHAT THIS STUDY ADDS⇒Early anticoagulation(<4days)after ischaemic stroke due to AF reduces the rate of new silent isch-aemic lesions at 1month without increasing the rate of new haemorrhage.HOW THIS STUDY MIGHT AFFECT RESEARCH,PRACTICE OR POLICY⇒Early anticoagulation after mild-to-moderate acute ischaemic stroke due to AF might be safe,howev-er,the results require further validation with ran-domised trials.