(957) Evaluation of Fixed-Dose Versus Weight-Based Dosing of 4F-PCC for Oral Factor Xa Inhibitor Bleeding

Introduction: Four-factor prothrombin complex concentrate (4F-PCC) is often used for the reversal of oral factor Xa inhibitors (OFXaI), but scant literature exists to guide dosing. This study sought to compare hemostatic efficacy and safety of weight-based 4F-PCC and fixed dose 4F-PCC for the treatment of OFXaI-related bleeding.

Methods: A retrospective cohort study conducted by chart review of electronic medical records at North Kansas City Hospital from September 2020 to August 2021 and January 2023 to June 2023 was completed. All patients who received 4F-PCC as treatment or prevention of OFXaI-related bleeding were included. Patients were excluded if they were less than 18 years of age or received 4F-PCC prior to hemodialysis catheter or central line placement. Weight-based dosing was administered as 25-50 units/kg based upon indication and fixed dose was administered as 2,000 units.

Results: Of the 63 patients evaluated, 36 received weight-based dosing and 27 received fixed dose. The cohort was 50% male with a median age of 75 years, and a majority were on apixaban (81%) for atrial fibrillation (65.1%) – all baseline characteristics were similar between groups (all p > 0.05). Intracranial hemorrhage was the indication for 4F-PCC in 33.3% of weight-based patients and 51.9% of fixed dose patients (p = 0.14). A total of 66.7% of weight-based patients and 70% of fixed dose patients met major bleeding event criteria (p = 0.75). The mean dose of 4F-PCC in the weight-based dosing group was higher than in the fixed dose group: 30.2 units/kg versus 25.8 units/kg (p = 0.09). Good hemostatic efficacy was achieved in 78.6% of weight-based patients and 88% of fixed dose patients (p = 0.36). The 30-day mortality and thromboembolic event rates were similar between groups with a mortality rate of 30.3% in the weight-based group versus 19.2% in the fixed dose group (p = 0.39) and a thrombosis rate of 3% in the weight-based group versus 11.1% in the fixed dose group (p = 0.18).

Conclusions: Fixed dose 4F-PCC provided a similar hemostatic efficacy and safety profile as weight-based 4F-PCC dosing irrespective of the type or severity of the bleeding event. Further prospective, randomized trials are necessary.