Healthcare Resource Use Among US Veterans Treated With Andexanet Alfa or 4-factor Prothrombin Complex Concentrate for Factor Xa Inhibitor-related Major Bleeding

S. Scott Sutton^1,2, Joseph Magagnoli^1,2, Tammy H. Cummings^1,2, Mary J. Christoph³, Raymond Chang,³ Hungta Chen³, Phillip Hunt³, James W. Hardin^1,4

¹Dorn Research Institute, Columbia VA Healthcare System (151), 6439 Garners Ferry Road, Columbia, South Carolina 29209 USA; ²Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, University of South Carolina, Columbia SC USA; ³AstraZeneca Pharmaceuticals, Wilmington, DE, USA; ⁴Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC USA.

Background: Major bleeding in the presence of factor Xa (FXa) inhibitors is associated with morbidity and mortality.

Aims: Describe healthcare resource utilization associated with use of andexanet alfa or 4-factor prothrombin complex concentrate (4F-PCC) for the management of major bleeding among US veterans treated with oral FXa inhibitors or enoxaparin.

Methods: This retrospective cohort study included data from inpatient medical records and Veteran Affairs vital status files extracted from the Veterans Affairs Informatics and Computing Infrastructure between March 2014–May 2022. Eligible patients were ≥age 18; hospitalized with a major bleed (intracranial hemorrhage [ICH], gastrointestinal, or other bleeding) while treated with apixaban, rivaroxaban, edoxaban, or enoxaparin; and managed with andexanet alfa or 4F-PCC. Descriptive or unadjusted analyses were used to assess hospital length of stay (LOS), intensive care unit (ICU) LOS, and readmissions. This study was supported by Alexion, AstraZeneca Rare Disease and was approved by the Federal Government Oversight Board (#1657754).

Results: The sample included 1,005 US veterans (n=200 andexanet alfa; n=805 4F-PCC). Patients treated with andexanet alfa were significantly older (76.4 vs. 73.1 years), and proportionally more had ICH bleeds (32.0% vs. 25.5% for 4F-PCC, Table 1). Mean hospital LOS and ICU LOS were almost one day less each for patients treated with andexanet alfa than for those treated with 4F-PCC (LOS difference: −0.93, 95%CI: [−3.83, 2.65]; ICU LOS difference: −0.96, 95%CI: [−2.11, 0.25], Table 2). Significantly fewer andexanet alfa–treated patients were admitted to the ICU (odds ratio [OR]: 0.54, 95%CI: [0.37, 0.79]) and had emergency readmissions within 30 days of the bleeding event (OR: 0.37, 95%CI: [0.14, 0.83]), whereas all-cause (including planned) readmissions were similar compared to 4F-PCC (Table 2).

Conclusion: Among US veterans with FXa inhibitor-related major bleeding, LOS was numerically lower, while ICU admission and emergency visits were significantly lower, for patients treated with andexanet alfa compared to 4F-PCC.

Table 1. Characteristics for US veterans hospitalized with Factor Xa inhibitor–related bleeds treated with andexanet alfa or 4F-PCC.

4F-PCC, 4-factor prothrombin complex concentrate; GI, gastrointestinal; ICH, intracranial hemorrhage; SD, standard deviation.

^aDue to patient privacy, frequencies including fewer than 5 patients cannot be reported.

Table 2. Healthcare resource use outcomes among US veterans treated with andexanet alfa or 4F-PCC.

4F-PCC, 4-factor prothrombin complex concentrate; ICU, intensive care unit; SD, standard deviation.

^aOR=odds ratio (95% confidence interval [CI]); ^bMean difference (95% CI), via non-parametric bootstrap.

The content of this abstract is solely the responsibility of the authors and does not necessarily represent the official views of the US Department of Veterans Affairs, nor does mention of trade names, commercial products or organizations imply endorsement by the US government. This abstract represents original research conducted using data from the Department of Veterans Affairs and is the result of work supported with resources and the use of facilities at the Dorn Research Institute, Columbia VA Health Care System, Columbia, South Carolina.