Atrial fibrillation in stroke patients: facts, numbers and current challenges.

Atrial fibrillation (AF) is a leading, modifiable risk factor for ischaemic stroke, with 20-30% of stroke patients harbouring underlying AF. Management of AF, however, differs substantially depending on clinical context. In ischaemic stroke patients with pre-known AF, direct oral anticoagulants (DOACs) are the cornerstone of secondary prevention, with initiation timing guided by infarct severity following a risk-adapted approach. In patients with no history of AF, prolonged cardiac rhythm monitoring after stroke or transient ischaemic attack improves AF detection rates. However, it remains uncertain whether this translates into a reduced risk of recurrent stroke, with randomised trials such as Find-AF 2 ongoing. Subclinical AF, detected via implantable devices, is associated with an increased stroke risk correlating with arrhythmia burden; recent trials (ARTESiA, NOAH-AFNET 6) suggest that anticoagulation may reduce ischaemic stroke risk in this population, but at the cost of increased bleeding, necessitating individualised decision-making. Particularly challenging are anticoagulation decisions with concomitant cerebral amyloid angiopathy or prior intracerebral haemorrhage (ICH) due to competing risks of thromboembolism and haemorrhage. Recent meta-analyses indicate that resuming DOACs after ICH reduces ischaemic events but significantly raises the risk of recurrent haemorrhage, without clear improvement in net clinical benefit. New treatment options, such as left atrial appendage closure, carotid artery filter systems, factor XIa inhibitors or rhythm control, must demonstrate in adequately powered randomised controlled trials that they can optimise treatment outcomes in this complex and growing patient group. This article summarises some common interdisciplinary neurological and cardiological questions and discusses the most recent evidence on AF-related stroke prevention across various patient groups, highlighting the importance of individualised, multidisciplinary, and imaging-informed decision-making.