Abstract 4136743: Current Oral Anticoagulation Use Among Patients With Atrial Fibrillation and Risk Factors Associated With Inadequate Treatments: A Report From a UK Population Cohort Study

Background: The worldwide prevalence of atrial fibrillation (AF) continues to grow with approximately 60 million cases each year. Aim: To understand demographic and clinical attributes of patients receiving adequate DOAC (direct oral anticoagulant) treatment, DOAC undertreatments, or no OAC (oral anticoagulant) treatments, thus providing valuable perspectives into the current landscape of stroke prevention in AF within the UK. Methods: We used the Clinical Practice Research Datalink (CPRD) Aurum database from January 2020 to March 2021 for this retrospective observational study. Patients’ characteristics from various cohorts (standard dose [SD], low dose [LD] per label, LD inconsistent per label prescribing, and untreated) were evaluated based on OAC treatment. Duration of index OAC treatment, time to discontinuation and incidence rates across OAC treated cohorts were assessed. A machine learning method (Elastic Net) identified factors associated with being undertreated or untreated. Results: The final sample included 13,341 patients (mean age 78.5 and female 47%). Within a 180-day timeframe post-diagnosis, 76% of patients received OAC treatment, while 24% did not receive any OAC therapy. Among those treated with DOAC (n=9947), 74% were administered SD (n=7238), 18% received LD per labels (n=1756) and 10% were inappropriately prescribed LD of DOACs (n=953). Both LD cohorts tended to have shorter duration of OAC therapy (figure) and higher discontinuation rates (per 100 person-years; LD per label: 42.97; LD not per label: 39.11) compared to the SD cohort (SD: 31.67). Patients who were untreated were associated with elevated bleeding risk factors such as renal disease and prior bleeding history; patients who received inappropriate LD were associated with age above 75, renal disease, GI conditions with PPI (proton pump inhibitor) concomitant treatments when compared to SD cohort. Conclusions: In our study, a considerable proportion of AF patients remained untreated/undertreated and were associated with bleeding risk factors, highlighting the unmet needs within this population. Exploring potential alternative treatment options with enhanced safety profiles could offer substantial benefits to patients in need.