ABSTRACT NUMBER: ESOC2026A2399 OUTCOMES OF TREATMENT DISCONTINUATION IN NON-VALVULAR ATRIAL FIBRILLATION: A NATIONWIDE REGISTRY STUDY

Abstract Background and aims Atrial fibrillation increases mortality and stroke risk; DOACs are first-line. Lacking routine monitoring, persistence is vital. We assessed adverse outcomes after discontinuation, with or without preceding events. Methods This nationwide retrospective cohort study linked three Swedish registries (AURICULA, National Patient Registry, and Prescribed Drug Registry). Patients with non-valvular AF initiating OAC were followed from treatment start until death, study end, valvular diagnosis, or reinitiation after interruption. Discontinuation was defined as a treatment gap >28 days. Clinical events within 14 days prior to discontinuation were assessed, and subsequent thromboembolic, bleeding, and mortality outcomes were recorded. Logistic regression evaluated determinants of continued therapy, discontinuation, or death. Results Among 68,277 patients (mean age 74.9 years; 44.7% women), apixaban was the most prescribed DOAC and showed the highest persistence (91.8%), while warfarin had the highest discontinuation. Event rates were markedly lower in treatment-persistent patients compared with discontinuers (all-cause mortality 4.6 vs. 16.1–35.2 per 100 person-years; stroke/systemic embolism 1.4 vs. 3.3–4.8). The highest risks occurred during the first 28-day washout period, particularly among patients with preceding adverse events. Cancer, intracranial hemorrhage, and new-onset anemia increased the likelihood of remaining off OAC beyond 28 days, whereas ischemic stroke was associated with treatment reinitiation. Cumulative discontinuation was lowest with apixaban and highest with warfarin. Conclusions In this nationwide cohort, OAC persistence was linked to lower mortality and thromboembolism. Discontinuers, especially early, had markedly higher risks, requiring close monitoring. Apixaban showed superior persistence. Because bleeding drives discontinuation, proactive bleeding-risk management is essential. Conflict of interest Hayder Kadhim: Nothing to disclose