Real-World Use and Impact of Direct Oral Anticoagulants in Cardioembolic Stroke Patients with Atrial Fibrillation

Background and Objectives: Atrial fibrillation (AF) is a primary cause of cardioembolic stroke (CS). AF-related mortality increased substantially in Eastern Europe in the last decade. While direct oral anticoagulants (DOACs) are effective for stroke prevention, non-adherence is a major clinical problem. This study aimed to investigate real-world DOAC usage among AF patients presenting with stroke and to evaluate the impact of prior DOAC therapy on stroke severity. Materials and Methods: This retrospective study analysed data from CS patients with AF admitted to the two largest Latvian university hospitals from January 2022 to December 2024. Secondly, a propensity-matched analysis was performed on a single-centre cohort to compare outcomes between patients receiving DOAC therapy and those not. Results: Of 2773 patients enrolled, the largest subgroup (45%) consisted of patients with known AF who were not on appropriate anticoagulation therapy before the stroke event. The propensity-matched analysis based on demographics, arrival time, AF type, and CHA 2 DS 2 -VA score (163 patients per group) revealed that patients taking DOACs presented with significantly milder strokes than non-users (mean admission NIHSS: 9.8 vs. 11.6, p=0.009). 40.5% of DOAC users received a reduced DOAC dose, and in 22.1% the DOAC dose was reduced inadequately. Stroke patients on DOAC therapy had significantly larger left atrial volume indices (LAVI) than non-users (56.4 vs. 48.0, respectively; p=0.004). Conclusions: Non-adherence to DOACs represents a substantial contributor to the CS burden. Prior DOAC use is associated with significantly reduced initial stroke severity, highlighting the protective benefit of therapy even when it fails to prevent an event.