Guideline Directed Anticoagulant Treatment and Dosing in a Contemporary Atrial Fibrillation Cohort: Analysis of the TRANSECT-AF Program.

Background: Optimal thromboprophylaxis in atrial fibrillation (AF) requires the accurate application of modern clinical guidelines. We evaluated the point prevalence and factors associated with nonguideline-directed anticoagulation and direct oral anticoagulant (DOAC) dosing in Canadian patients with AF. Methods: TRANSECT-AF is a retrospective registry of consecutive Canadian patients with AF collected between March 2021 and August 2023. Patients were categorized as guideline directed therapy (GDT) or nonguideline-directed therapy (NGDT) based on concordance of their reported thromboprophylaxis with the CHADS-65 algorithm. Patients on GDT with a DOAC were subcategorized as concordant or discordant dosing based on concordance of their reported DOAC doses with the 2020 Canadian Cardiovascular Society AF dosing recommendations. Results: In total, 3043 patients were included (median age 77, 37% women, median CHADS-VASc score 4, median HAS-BLED score 2) and 11% received NGDT, which was independently associated with younger age, lower thromboembolic risk, better renal function, and antiplatelet therapy. Within the GDT cohort, 32% of patients were on guideline discordant DOAC doses. Older age, lower body mass index, female sex, lower renal function, higher thromboembolic risk and non-apixaban DOAC use were independently associated with discordant dosing. Conclusions: Within this Canadian AF registry, 11% of patients were on NGDT and 32% of patients on GDT with a DOAC were treated with a guideline-discordant dose. Our analysis describes predictors of guideline discordant anticoagulation and DOAC dosing that may be used to identify target populations for future quality improvement initiatives in AF thromboprophylaxis.