Antithrombotic Therapy in Atrial Fibrillation Management in Western Australia: Temporal Trends and Evidence-Treatment Gaps

Objective To describe temporal trends in appropriate antithrombotic therapy use in hospitalised atrial fibrillation (AF) patients and identify evidence-treatment gaps in clinical practice. Design Retrospective cohort study from January 2009-March 2016. Setting Tertiary and secondary teaching hospitals in Perth, Western Australia. Participants Hospitalised adults with non-valvular AF. Results We identified 11,294 index AF admissions, with a mean age of 76.9 years, 45.8% women and 86.3% at high risk of stroke (CHA(2)DS(2)-VASc score >= 2 in men and >= 3 in women). In high risk subjects use of appropriate antithrombotic therapy improved over time with increasing oral anticoagulant (OAC) use and declining sole antiplatelet use (both trend p<0.001). However, by study end only 45.3% of high-risk patients were receiving OAC therapy. In low risk patients, receipt of OAC therapy was steady throughout the study at 40.5% (trend p=0.10). The gender gap in OAC use narrowed over time, with no significant difference between high risk men and women by study end. Use of OAC therapy in elderly patients (age >= 75 years) remained lower than younger patients (age <65 years) over the entire period, with only 31% of elderly patients receiving OAC therapy at study end. From 2012 onwards use of non-vitamin K oral an-ticoagulants (NOACs) doubled each year with declining warfarin use (both trend p<0.001). Conclusion Despite substantial uptake of NOACs, OAC therapy in AF patients at high risk of stroke remains under-utilised in Western Australia and over-utilised in low risk patients. Further work is required to reduce treatment-risk mismatch for stroke prevention in AF patients.

Automated summary

The study found that appropriate antithrombotic therapy in high-risk atrial fibrillation patients improved over time but remained underutilized, while low-risk patients showed overutilization. Elderly patients had lower rates of oral anticoagulant therapy. Additionally, the use of non-vitamin K oral anticoagulants (NOACs) increased over time while warfarin use declined.