ABSTRACT NUMBER: ESOC2026A1598 DRUG INTERACTIONS AND OUTCOMES OF BREAKTHROUGH ISCHEMIC STROKE DESPITE APPROPRIATE ORAL ANTICOAGULATION: RESULTS FROM THE ASPERA-R STUDY

Abstract Background and aims Breakthrough ischemic stroke despite appropriate oral anticoagulant (OAC) therapy may be related to concomitant use of drugs that interact with OACs and reduce their efficacy. We assessed the prevalence and types of interacting drugs and their impact on outcomes. Methods The retrospective, multicenter ASPERA-R study consecutively included patients with breakthrough ischemic stroke despite appropriate OAC therapy. Interacting drugs were identified from the Summary of Product Characteristics. Ninety-day case-fatality, recurrent cerebral ischemic events, and major bleeding were compared between patients with and without interacting treatments using inverse probability weighting (IPW), adjusting for age, sex, and vascular risk factors. Results Among 1,649 patients (860 women, 52.2%; mean age 78.3 ± 10.4 years), 469 (28.4%) were receiving interacting drugs at stroke onset, including proton pump inhibitors (450, 27.3%), antiseizure medications (28, 1.7%), H2 inhibitors (3, 0.2%), dexamethasone (3, 0.2%), and ketoconazole (1, 0.1%). At 90 days, death occurred in 100 patients (21.3%) with interacting treatments and 234 (19.8%) without. Recurrent cerebral ischemic events occurred in 23 (4.9%) and 34 patients (2.9%), respectively, and major bleeding in 20 (4.3%) and 35 patients (3.0%). After IPW, no differences were observed in recurrent ischemic events or major bleeding, while case-fatality was slightly higher in patients receiving interacting drugs (21.0% vs 17.2%; p=0.049). Conclusions More than one-quarter of patients with breakthrough ischemic stroke despite appropriate OAC therapy were treated with potentially interacting drugs, without substantial impact on short-term clinical outcomes. Conflict of interest None