Real‐World Direct Oral Anticoagulants Experience in Atrial Fibrillation: Falls Risk and Low Dose Anticoagulation are Predictive of both Bleeding and Stroke Risk

BACKGROUND: Clinical trials have demonstrated that direct oral anticoagulants (DOAC) are non-inferior to vitamin K antagonist for stroke prevention in non-valvular atrial fibrillation (AF) with comparable safety outcomes; however real-world Australian data is limited. AIMS: We aim to evaluate local real-world DOAC use focusing on safety, particularly in high-risk patients. METHODS: A retrospective evaluation of 658 patients commenced or continued on DOAC between September 2013-September 2016 for non-valvular AF at Northern Hospital, a tertiary hospital in Victoria, Australia was performed. RESULTS: Factor Xa inhibitors were more commonly prescribed than direct thrombin inhibitor (83.3% vs 16.7%) for AF management. The median patient age was 75 years. The rate of clinically significant bleeding on anticoagulation was 3.13 per 100 person-years (including four deaths) with risk factors including history of bleeding (HR 3.52, 95% CI 1.22-10.17), concurrent antiplatelet therapy (HR 2.62, 95% CI: 1.11-6.20) and high falls risk (HR 2.76, 95% CI: 1.26-6.08). Patients on low dose DOAC had significantly higher bleeding risk compared to those on full dose (5.05 vs 1.82 per 100 person-years). The rate of thrombotic stroke despite anticoagulation was 1.34 per 100 person-years with risk factors including low dose anticoagulation (p = 0.034), high falls risk (p = 0.046) and previous stroke (p = 0.028). CONCLUSIONS: DOAC use in real-world Australian practice is safe and effective, consistent with international data. Low dose anticoagulation and falls risk are associated with increased bleeding and thrombotic risk demonstrating overlapping risk factors. Careful individualised patient risk assessment is still required as low dose anticoagulation is not without risks. This article is protected by copyright. All rights reserved.