The Utilisation of Antithrombotic Therapy in Older Patients in Aged Care Facilities with Atrial Fibrillation

Introduction: Oral Anticoagulants are essential drugs for the prevention of thromboembolic events in patients with atrial fibrillation (AF). While the underutilisation of anticoagulants in elderly patients with AF has been demonstrated internationally, few studies have been conducted among aged care residents in Australia.

Aims: The aim of this study was to determine the utilisation of anticoagulants with respect to stroke and bleeding risk among people with AF residing in aged care facilities.

Methods: We performed a non-experimental, retrospective analysis designed to evaluate antithrombotic usage in older patients with AF in Australia using data collected by pharmacists while performing Residential Medication Management Reviews (RMMRs). The utilisation of antithrombotic therapy and the appropriateness of therapy were determined based on the CHADS2, CHA2DS2-VASc and HAS-BLED risk stratification schemes, and the appropriateness of therapy was considered in the light of documented contraindications to treatment. Predictors of anticoagulant use were determined using multivariate logistic regression.

Results: A total 1952 RMMR patients with AF were identified. Only 35.6% of eligible patients (CHADS2 score ≥2 and no contraindications to anticoagulants) received an anticoagulant. As age increased, the likelihood of receiving an anticoagulant decreased, and the likelihood of receiving antiplatelet therapy or no therapy increased. In patients with a high risk of stroke (CHADS score ≥2), utilisation of anticoagulants dropped by 19.7% when the HAS-BLED score increased from 2 to 3, suggesting that physicians placed a heavier weighting on bleeding risk rather than stroke risk in the study population.

Discussion: Anticoagulant medications appeared to be underused in this elderly population, whose risk of stroke often exceeded their risk of bleeding. Prescribing of anticoagulants was influenced to a greater extent by bleeding risk than it was by the risk of stroke. Further research investigating whether the availability of direct oral anticoagulants changes practice in this patient population is needed.