Utilization of Dabigatran for Atrial Fibrillation at 3 Tertiary Care Centres

The outpatient management of stroke prevention for patients with atrial fibrillation has recently been published and provides insight into the benefits and risks of the new direct-acting oral anti-coagulants. However, real-world use of these agents for hospital inpatients requires additional study.

To determine prescribing patterns for dabigatran at 3 Canadian hospitals, specifically adherence with the hospitals' prescribing restriction limiting dabigatran to patients with nonvalvular atrial fibrillation and creatinine clearance above 30 mL/min (primary outcome) and assessment of age-related prescribing, prescribing of medications with defined contraindications or potential for interaction when given concurrently with dabigatran, and use of risk stratification tools (secondary outcomes).

A retrospective chart review of patients for whom dabigatran was prescribed from August to October 2011 was performed at 3 hospitals in Toronto, Ontario. Descriptive statistics were used for all outcomes assessed.

Overall, dabigatran was prescribed for 69 inpatients, of whom 16 (23%) were new users (dabigatran initiated during hospital admission) and 53 (77%) were prior users (dabigatran prescribed before admission to hospital). Fifty-eight patients (84%; 14 new users and 44 prior users) received dabigatran according to the hospitals' prescribing restriction. For the remaining 11 patients, dabigatran therapy did not meet prescribing restrictions for use because of valvular disease or presence of prosthetic valve (10 patients [14% of the total sample]) and impaired renal function (1 patient [1%]). Among those whose dabigatran therapy met the prescribing restrictions for use, amiodarone and acetylsalicylic acid were the most common concurrently prescribed medications (17 patients [29%] and 14 patients [24%], respectively). Stroke and bleeding risk were documented for only 27 patients (47%) and 10 patients (17%), respectively.

At the study hospitals, dabigatran was appropriately prescribed for the indication of nonvalvular atrial fibrillation in patients without renal impairment in most cases. However, greater consideration of cardiac history (including valvular disease and presence of prosthetic valves), drug interactions, and documentation of risks and benefits is warranted. These research findings highlight the importance of and opportunity for pharmacist review and involvement in assessment and selection of patients with indications for anticoagulant therapy, particularly when agents are new to the market.