Real-World Efficacy and Safety of Apixaban vs. Warfarin in Obese Atrial Fibrillation Patients: Propensity Matching Analysis.

Background/Objectives: The use of direct oral anticoagulants (DOACs) in obese patients is scarcely studied despite having many advantages over warfarin. Consequently, this study aims to assess the real-world safety and effectiveness of apixaban compared to warfarin in treating atrial fibrillation (AF) in obese patients. Methods: A retrospective cohort study examined consecutive AF patients with a BMI of ≥ 30 kg/m² treated with apixaban or warfarin. Patients were started on these medications between January 2015 and December 2021. Efficacy outcomes included ischemic stroke and venous thromboembolism (VTE) occurrences, while safety outcomes encompassed bleeding incidents and mortality rates. Outcomes were assessed following propensity score matching. Results: We identified 876 patients treated with either apixaban (414) or warfarin (462). Their mean age was 76.9, with a mean CHA₂DS₂VASc score of 4.9 ± 1.97. After matching and compared to warfarin, apixaban was correlated with a lower incidence of all-cause mortality (19.7% vs. 33.7%, p < 0.001). The incidences of stroke, venous thromboembolism (VTE), and bleeding events were (4.7% vs. 4.7%, p = 1.000), (1.0% vs. 2.6%, p = 0.107), and (3.9% vs. 6.2%, p = 0.139), respectively. Using Cox-regression model, apixaban was associated with lower mortality risk (HR = 0.728, 95% CI: 0.55-0.97; p = 0.030) which remained significant after adjusting for the conventional cardiovascular risk factors and BMI values. Conclusions: Apixaban is associated with a trend of reduced incidence of thromboembolism among obese patients with atrial fibrillation and significantly lowers all-cause mortality. Despite earlier concerns, the use of apixaban is an effective and safe alternative to warfarin among obese patients with AF.