Opportunities for de-escalation of aspirin therapy in patients with atrial fibrillation at high stroke risk receiving direct oral anticoagulants

Objectives

Atrial fibrillation (AF) is associated with increased risk of stroke that can be attenuated with newer anticoagulants, called direct oral anticoagulants (DOACs). Before the emergence of DOACs, warfarin or aspirin (ASA) was used for stroke prevention. Owing to the increased risk of bleed with concomitant anticoagulation therapy, populations that may benefit from ASA therapy are becoming limited. The primary objective of this study was to evaluate ASA utilization in an outpatient setting for patients with AF at high risk of stroke receiving a DOAC. The secondary objective was to evaluate what characteristics influence ASA use using a multivariate logistical regression model.

Design

This was a retrospective study conducted through electronic health record extraction between June 1, 2021, and May 31, 2022.

Setting and participants

Study sites included 219 outpatient Banner Health Facilities. A total of 5716 patients were included in the study.

Outcome measures

Patient characteristics and demographics, including CHA₂DS₂-VASc and HAS-BLED scores, were evaluated in adults 18 years and older with AF and an active DOAC prescription.

Results

There were 955 patients (16.7%) on ASA and 4761 patients (83.3%) not on ASA. Of the 955 patients on ASA, 33% (n = 315) did not have vascular disease. A total of 2289 patients had at least one vascular disease diagnosis. Of these patients, 28% (n = 640) were on ASA and 72% (n = 1649) were not on ASA. There were 142 patients with vascular disease who experienced a bleeding event with 36% of patients (n = 51) on ASA. Patients on ASA had a higher average CHA₂DS₂-VASc score (4.02 vs. 3.74) and HAS-BLED score (3.10 vs. 2.35) than patients not on ASA, respectively.

Conclusion

This study found approximately one-third of patients with documented ASA use had no documentation of vascular disease and an unclear pattern of use in patients with documented vascular disease, suggesting opportunities to de-escalate ASA in patients with AF on a DOAC.