Utilisation of antithrombotic therapy for stroke prevention in atrial fibrillation in a Sydney hospital: then and now

Abstract

Objective: Evidence from pivotal clinical trials conducted more than a decade ago supports the use of antithrombotic therapy, particularly warfarin, for stroke prevention in atrial fibrillation (AF). Despite the wide dissemination of this evidence since that time, there is anecdotal evidence that utilisation of therapy remains suboptimal, especially in the target elderly population, which is reflected in the development of practice tools such as the TAG Clinical Indicator ('Antithrombotics in AF' Indicator 1.6, 2007). Therefore, the objective of this study was to determine the current utilisation of antithrombotic therapy for elderly patients with AF in the local setting, and to compare this utilisation with the results of a prior audit (AUDIT 1), as well as against the recommendations of the TAG Clinical Indicator (TAG IND).

Setting: A major teaching hospital in Sydney, Australia.

Method: A retrospective audit (AUDIT 2) of medical records of hospital inpatients (aged 65 years, with a significant diagnosis of AF), pertaining to admissions over the 12-month period 1st June 2006-31st May 2007, was conducted.

Main outcome measure: Proportion of patients receiving antithrombotic therapy at the point of discharge from hospital.

Results: A total of 201 patients (mean age 79.8 ± 7.8 years) were reviewed in AUDIT 2. Most (85%) patients received antithrombotic therapy (vs. 79.2%, AUDIT 1), with "warfarin ± antiplatelets" most frequently (46.3%) used (vs. 34.5%, AUDIT 1), followed by "aspirin ± other antiplatelet" (33.3% AUDIT 2 vs. 43.1% AUDIT 1). Patients aged 80 years were significantly less likely to receive warfarin therapy, compared to those <80 years (40.2% vs. 52.5%, P = 0.01). Of those patients who were deemed 'eligible' for warfarin according to AUDIT 2 (n = 155), only 55.0% of patients were actually prescribed this treatment. Results obtained by AUDIT 2 and TAG IND were overall comparable.

Conclusion: Whilst there have been temporal improvements in the overall utilisation of antithrombotic therapy, including warfarin, there are still significant gaps in the translation of evidence from clinical trials to clinical practice. Further sustainable intervention is warranted to help apply treatment recommendations to the target population.