Ce-454029-4 racial disparities in the use of oral anticoagulation for atrial fibrillation by sex and within high and low stroke risk populations

Atrial fibrillation (AF) is the most common arrhythmia and is associated with an increased risk of ischemic stroke. Oral anticoagulation (OAC) has been shown to reduce the risk of ischemic stroke in patients with AF. Previous studies have demonstrated that both females and Black, Hispanic, and Asian groups are less likely to be prescribed OAC. This study aims to determine if high or low CHA2DS2-VASc risk group is associated with any race, ethnic, or sex disparities in anticoagulation rates. A registry database of 118,727 patients was created containing pertinent clinical characteristics of all patients with a known diagnosis of AF using common Epic rules across the Mass General Brigham Hospital System in the inpatient and outpatient setting as of October 2022. Of these, 7,226 patients were excluded due to missing data leaving a total of 111,501 for the final analysis. Logistic regression models were used to assess the association between race and ethnicity (White, Black, Hispanic, Asian) and OAC use within low (0 – 1) and high (2 – 9) CHA2DS2-VASc risk groups, as well as within each sex group (Male, Female). Covariates used in risk adjustment included age, sex, insurance type, and HAS-BLED while the sex models were adjusted for age, insurance type, CHA2DS2-VASc, and HAS-BLED. In the low risk CHA2DS2-VASc group only Asian race was associated with a statistically lower rate of OAC compared to White race (Figure A), while in the high risk group this was only true for Black race (Figure B). Within male sex, Black, Hispanic, and Asian males showed a lower rate of OAC while within female sex, only Black females showed a lower rate of OAC (Table). Female sex irrespective of race is associated with lower rates of OAC compared to male. Compared to White females, Black females still are less likely to be prescribed OAC. Within a low risk CHA2DS2-VASc group, White race is equal or more likely to be on OAC. For high risk groups, only Black race is associated with a lower OAC prescription rate. These results provide evidence that subjective decision making may be contributing to racial disparities in OAC utilization in AF and that the largest disparities occur in Black patients.