The Utilization of Antithrombotic Therapy in Older Australians With Atrial Fibrillation

Abstract

What is known and objective: Oral anticoagulants are essential drugs for the prevention of thromboembolic events in patients with atrial fibrillation (AF). Anticoagulants are, however, commonly withheld due to a perceived risk of severe adverse events. The underutilization of anticoagulants in patients with AF has been demonstrated internationally, but to date, there are limited data available in the Australian context. The aim of this study was to determine the utilization patterns of anticoagulants (including novel oral anticoagulants) with respect to stroke and bleeding risk among patients with AF within the community.

Methods: We performed a nonexperimental, retrospective analysis designed to evaluate antithrombotic usage for AF in Australia. The utilization of antithrombotic therapy and the appropriateness of therapy were determined based on CHADS2, CHA2DS2-VASc and HAS-BLED risk stratification schemes. The presence of documented contraindications was used to determine the appropriateness of antithrombotic therapy.

What is new and conclusion: Anticoagulants were overutilized in patients at low risk of stroke and underutilized in patients at higher risk of stroke. As the HAS-BLED score increased, the likelihood of patients receiving an anticoagulant decreased regardless of CHADS₂ or CHA₂DS₂-VASc scores.

Keywords: anticoagulants; stroke; thrombosis prophylaxis.