Comparing the Safety and Effectiveness of Apixaban Lead-In Dosing Strategies in Hospitalized Adults With Venous Thromboembolism

<b>Background:</b> Clinicians often use parenteral lead-in regimens prior to direct oral anticoagulants (DOACs) for venous thromboembolism (VTE) in hospitalized patients due to shorter half-life and the ability to use laboratory monitoring. <b>Objective:</b> This study evaluates the effectiveness and safety of different apixaban lead-in durations for hospitalized adults with newly diagnosed VTE. <b>Methods:</b> Retrospective review of patients with one of the following lead-in regimens: (1) parenteral anticoagulation ≥ 48 hours with abbreviated course of apixaban lead-in, (2) parenteral anticoagulation ≥ 48 hours with full apixaban lead-in, or (3) no parenteral anticoagulation with full apixaban lead-in. All followed by maintenance apixaban for at least 6 months. Primary outcomes were incidences of recurrent VTE (rVTE) or bleeding events, in accordance with International Society on Thrombosis and Hemostasis (ISTH) definitions, within 6 months of the index visit. Data are presented descriptively and univariate analyses between groups performed. <b>Results:</b> Sixty-eight patients were included; rVTE (all deep vein thrombosis (DVT)) occurred in 2 patients (2.9%) and bleeding events (all clinically relevant non-major bleeding) occurred in 3 patients (4.4%) overall. There were no differences between groups; one patient in the parenteral group had full lead-in and one patient in the full-lead apixaban group had rVTE. One patient in the parenteral with full lead-in and 2 patients in the full lead-in apixaban group had a bleeding event (<i>P</i> = 0.99). Mean time to rVTE or bleeding event was 46 and 158 days, respectively. <b>Conclusions:</b> Similar safety and effectiveness were noted between the 3 apixaban lead-in regimens. These findings suggest that all 3 regimens provide similar outcomes, warranting further investigation to optimize lead-in strategies.