(125) Utilization of Factor Xa Inhibitors and Warfarin in Obese Nonvalvular Atrial Fibrillation (NVAF) Patients: Analysis of University Health Center Electronic Medical Records in The United States (US)

Publication Number: 799

Background: For five decades, vitamin K antagonists (VKAs) such as warfarin were the only oral anticoagulant medications for preventing stroke in atrial fibrillation (AF). The US Food and Drug Administration (FDA) has now approved factor Xa inhibitors for NVAF patients, which are rivaroxaban, apixaban, and edoxaban.

Objectives: To explore the utilization patterns of factor Xa inhibitors and warfarin in obese NVAF patients based on insurance coverage.

Methods: A retrospective cohort study using electronic medical records in the US from June 1st, 2012, to December 14th, 2020, was performed. Obese individuals who had a NVAF diagnosis with their first prescription of rivaroxaban, apixaban, or warfarin were included. Patients with any valve disease, transient atrial fibrillation, venous thromboembolism, pregnancy, or those who had knee or hip replacement surgery less than six weeks earlier were excluded. The total number of prescriptions for each factor Xa inhibitor (rivaroxaban and apixaban) and warfarin was calculated by adding the number of each prescription based on insurance coverage (Medicaid, Medicare, private, and other).

Results: The estimated average percentage of patients aged 65 years or older across all three cohorts was 65.33%. The total number of oral anticoagulant prescriptions (apixaban, rivaroxaban, and warfarin) was 591 among the Medicare population. This number includes 214 people who were using warfarin, 198 people who were using apixaban, and 179 people who were using rivaroxaban. The total number of Medicaid coverage for apixaban, rivaroxaban, and warfarin prescriptions was similar, showing 22, 25, and 20, respectively. People who carried private insurance showed similar utilization of rivaroxaban (86 prescriptions) and apixaban (86 prescriptions) compared to warfarin (57 prescriptions). Among patients with other insurance coverage, the highest total number of prescriptions was 18 for apixaban, followed by 16 for warfarin, and six for rivaroxaban.

Conclusions: The utilization of apixaban, rivaroxaban, and warfarin by obese NVAF patients was higher in the group with Medicare coverage than in groups with other types of coverage. Therefore, due to the higher number of Medicare carriers, our findings may only apply to the elderly population and not generalize to other types of insurance.