Ischaemic Stroke in Patients with Known Atrial Fibrillation: A Snapshot from a Large University Hospital Experience

<b>Objectives</b>: Atrial fibrillation (AF) is associated with high risk of ischaemic stroke (IS). Oral anticoagulant therapy (OAT) is the standard of care for stroke prevention, even though its management remains challenging in clinical practice. An emerging problem is embolic events occurring on adequately conducted OAT, the so-called resistant stroke (RS). We aimed to describe pre-stroke prevention therapy, management on hospital discharge, and therapy at follow-up in all patients with AF hospitalized for IS and in the RS subgroup. <b>Methods</b>: We conducted a retrospective monocentric study of patients with known AF hospitalized for an IS. A subgroup with RS was identified. We recorded information on prevention therapy at home, recommended therapy at discharge, and data on outcome and prevention therapy at follow-up. <b>Results</b>: We identified 226 patients, 61% females, median age 84.04 years. Preventive therapy at home was performed in 121 (53.5%) (119 OAT and 2 Left Atrial Appendage Occlusion). At hospital discharge OAT was prescribed to 78.2% of patients. RS was diagnosed in 33 patients whose management at discharge was: same OAT in 12, shift to another Direct Oral Anticoauglant (DOAC) in 5, from DOAC to Vitamin K Antagonist (VKA) and vice versa in 11, non-specified OAT in 4. At final, follow-up of 208 days (range 85-443) 23.3% (34/146) did not assume OAT. OAT was significantly associated with survival probability (<i>p</i> < 0.001). <b>Conclusions</b>: Our findings confirm a scarce adoption of guidelines for AF-related embolic events, even in the absence of absolute contraindication to OAT. RS remains an underexplored clinical entity with empirical management, highlighting the need for targeted research and tailored therapeutic strategies.