2026 Southeastern Residency Conference

Title: Evaluation of Two Four-Factor Prothrombin Concentrates for Anticoagulant Reversal   
Authors: Mary G. Johnson, Jessica Hernandez, Annmarie Vallomthail, Kristina Larizadeh, Nina Casanova, Feras Akbik
Background: Vitamin K antagonists (VKAs) and factor Xa inhibitors are oral anticoagulants used for the treatment and prevention of thromboembolic events. Bleeding is the most common adverse effect of oral anticoagulants, and rapid reversal may be required in cases of severe hemorrhage or when urgent surgery is indicated. Four-factor prothrombin complex concentrates (4F-PCCs), including Kcentra® and Balfaxar®, are standard treatments for reversal of VKAs and factor Xa inhibitors. Emory University Hospital recently changed formulary agents from Kcentra® to Balfaxar®. In one clinical trial, Balfaxar® was found to be non-inferior to Kcentra® for the reversal of warfarin for urgent surgery; however, there is a paucity of data directly comparing these agents for VKA and factor Xa inhibitor-related bleeding. Limited data and lack of guideline recommendations for a preferred 4F-PCC contribute to clinical uncertainty in selecting an optimal reversal agent. The objective of this study is to evaluate the safety and efficacy of Balfaxar® vs. Kcentra® for reversal of VKAs and factor Xa inhibitors.   
Methods: This study is an Institutional Review Board-approved, single-center, retrospective chart review of patients who received 4F-PCC from December 4, 2024 to August 1, 2025. Patients were included if they were at least 18 years of age, presented to Emory University Hospital, and received at least one dose of 4F-PCC for reversal of a VKA or factor Xa inhibitor. Patients were excluded if they received 4F-PCC at an outside hospital or for procedural use, were concomitantly taking a P2Y12 inhibitor, had a history of a congenital bleeding disorder, or were pregnant, nursing, or incarcerated. The primary outcome was hemostatic efficacy. Hemostatic efficacy in intracerebral hemorrhage (ICH) patients was defined as change in hematoma volume ≤ 20% or 21-35% within 24 hours of baseline without a repeat 4F-PCC dose or surgical intervention within 24 hours. In non-ICH patients, hemostatic efficacy was defined as a hemoglobin drop ≤ 2g/dL within 24 hours, or transfusion of < 2 units of packed red blood cells without a repeat 4F-PCC dose or surgical intervention within 24 hours. Secondary outcomes include in-hospital mortality, thrombotic events, ICU length of stay, hospital length of stay, and number of repeat doses within 48 hours. Descriptive statistics will be used to summarize the continuous and categorical variables. Chi-squared tests will assess differences in outcomes between treatment groups.  
Results: Out of 71 patients, 37 patients were included in the Kentra® group and 34 in the Balfaxar® group. Baseline characteristics were similar between the groups except BMI of 25-29.9 kg/m2 was notably different (45.9% vs. 14.7%, p=0.004). A total of 20 patients in the Kcentra® group and 19 in the Balfaxar® group met the primary outcome of hemostatic efficacy (54.1% vs. 50.0%, p=0.877). There were notable differences between in-hospital mortality (13.5% vs. 32.4%, p=0.058) and number of repeat doses (0.0% vs. 8.8%, p=0.065), but these findings, along with the other secondary outcomes, were not statistically significant. However, there was a significant increase in thrombotic events (ischemic stroke) in the Balfaxar® group (0.0% vs. 14.7%, p=0.016).  
Conclusion: There was no significant difference in hemostatic efficacy between Kcentra® and Balfaxar®. While no difference in efficacy was observed, ischemic stroke, in-hospital mortality, and repeat doses within 48 hours were more notable in the Balfaxar® group. Larger studies are needed to validate these results and further guide the selection of the optimal reversal agent.