Dabigatran Compared With Warfarin for Stroke Prevention With Atrial Fibrillation: Experience in Hong Kong

Background: Dabigatran is an oral direct thrombin inhibitor recently approved for stroke prevention in atrial fibrillation (AF) as an alternative to warfarin. The primary advantages of dabigatran are freedom from monitoring and less interaction with other drugs and food. It is ideal for patients who are unwilling to adhere to regular coagulation monitoring or whose therapeutic effect using warfarin is not optimal despite adequate monitoring and management. However, the impact of dabigatran on health-related quality of life (HRQoL) and drug compliance has been less evaluated. This study aimed to evaluate the clinical and humanistic outcomes of dabigatran use in Hong Kong. Hypothesis: Dabigatran 110 mg twice daily was non-inferior in stroke prophylaxis in AF patients compared to adjusted-dose warfarin; while dabigatran 150 mg twice daily was superior to adjusted-dose warfarin in the real world data in Hong Kong. Methods: We retrospectively analyzed 244 patients with newly diagnosed AF and prescribed dabigatran (n = 122) or warfarin (n = 122) for stroke prophylaxis from the Prince of Wales Hospital between January 2010 to November 2011. Clinical outcomes including death, stroke, bleeding, and HRQoL using the EuroQol EQ-5D-5L were compared between patients on dabigatran and warfarin. Results: The median duration of follow-up was 310 days. Stroke occurred in 2 patients (1.64%) in the dabigatran group and 4 in the warfarin group (3.28%) (adjusted hazard ratio [HR]: 0.53, P = 0.47). Bleeding of any degree occurred in 28 patients on dabigatran and 38 patients on warfarin (adjusted HR: 0.76, P = 0.28), with age over 70 years and renal impairment being significant positive predictors of bleeding (P = 0.01 and 0.02, respectively). Dyspepsia was the most common adverse event of dabigatran over warfarin (19.7% vs 8.2%, P = 0.01). Rate of discontinuation of dabigatran was 25.4%, with dyspepsia being the most common cause for discontinuation (6 patients, 4.92%). There was no significant difference in drug compliance or HRQoL at 1 year between the 2 groups (utility score 0.77 [dabigatran] vs 0.74 [warfarin], P = 0.28). Conclusions: In Hong Kong, the clinical efficacy and safety of dabigatran were comparable to that of warfarin, and drug compliance and HRQoL of using dabigatran and warfarin were similar after 1 year of use. Clin. Cardiol. 2012 DOI: 10.1002/clc.22069 This study was supported by the School of Pharmacy, The Chinese University of Hong Kong. The authors have no other funding, financial relationships, or conflicts of interest to disclose.