Abstract Number: Esoc2026a2408 Ischemic Stroke Despite Primary Preventive Oral Anticoagulation in Atrial Fibrillation—a National Registry Study

Abstract Background and aims In patients with atrial fibrillation suffering an ischemic stroke despite primary preventive DOAC therapy, several strategies exist for subsequent anticoagulation. We aimed to investigate which strategy is associated with recurrence-free survival. Methods We used data from the Swedish national stroke register Riksstroke on patients with ischemic stroke despite primary preventive DOAC treatment for atrial fibrillation during 2016-23. Patients were divided into four groups: Keeping the same DOAC, Switching to DOACs with the same mechanism, Switching to DOAC with different mechanism or Switching from DOAC to VKA. The primary outcome was the composite of recurrent ischemic stroke, hemorrhagic stroke and all-cause mortality within the follow-up period of 90 (+/- 15) days. Secondary outcomes were these components taken separately. Multivariate logistic regression and Cox regression were used adjusting for age, sex, common stroke risk factors, stroke severity and treating hospital. Results Complete data for anticoagulant choice and follow-up was available in 4466 patients. Compared to keeping the same DOAC the group switching from DOAC to VKA showed a significantly worse primary outcome (adjusted OR 1.98, 95% CI 1.02–3.60, P = 0.032) and secondary outcome regarding mortality (adjusted OR 2.29, 95% CI 1.12–4.33, P = 0.016). The other DOAC switching strategies showed no significant differences versus keeping the same DOAC. Conclusions In this large national registry-based analysis of outcomes in breakthrough ischemic stroke while on DOAC therapy, switching to VKA was associated with worse outcomes compared to keeping the initial DOAC. Further analyses will be performed and reported on long-term follow-up. Conflict of interest Hannes Frejd: nothing to disclose, Michael Mazya: nothing to disclose, Boris Keselman: nothing to disclose. Figure 1 - belongs to Results