Stroke risk assessment for atrial fibrillation: hospital-based stroke risk assessment and intervention program

Background: Despite the proven effectiveness of antithrombotic therapy for atrial fibrillation (AF), the treatment remains suboptimal. The aim of this study was to implement and evaluate a system to improve the appropriate use of antithrombotics for stroke prevention in AF utilizing a clinical pharmacist as a stroke risk assessor.

Method: Hospital in-patients with AF were prospectively identified and they received a formal stroke risk assessment from a pharmacist. The patients’ risk of stroke was assessed and documented according to Australian guidelines and a recommendation regarding antithrombotic therapy was made to the medical team on a specially designed stroke risk assessment form.

Results: One hundred and thirty-four stroke risk assessments were performed during the intervention period. For those patients at high risk of stroke and with no contraindication present (warfarin-eligible patients), 98% were receiving warfarin on discharge from hospital compared to 74% on admission (P < 0.001). Of the 50 (37%) assessments that recommended a change of therapy, 44 (88%) resulted in a change in the patient’s current antithrombotic therapy compared to their admission therapy. Thirty (68%) of the assessments resulted in an ‘upgrade’ to more-effective treatment options for example from no therapy to any agent or from aspirin to warfarin.

Discussion and Conclusion: The pharmacist-led stroke risk assessment program resulted in a significant increase in the proportion of patients receiving appropriate thromboprophylaxis for stroke prevention in AF. The methods used in this study should be evaluated in a larger trial, in multiple hospitals, with different pharmacists performing the intervention.