Introduction: Outcomes associated with suboptimal use of antithrombotic treatments (antiplatelets, warfarin, direct oral anticoagulants [DOACs]) are unclear in Chinese patients with atrial fibrillation (AF).
Objectives: Our objective was to assess the prescription patterns, quality, effectiveness, and safety of antithrombotic treatments.
Methods: This was a population-based cohort study using electronic health records in Hong Kong. Patients newly diagnosed with AF during 2010-2016 were followed up until 2017. Patients at high stroke risk (CHA2DS2-VASc score ≥ 2) and receiving antithrombotic treatments were matched using propensity scoring. We used Cox proportional hazards regression to compare the risks of ischemic stroke, intracranial hemorrhage (ICH), gastrointestinal bleeding (GIB), and all-cause mortality between groups.
Results: Of the 52,178 high-risk patients with AF, 27,614 (52.9%) received antithrombotic treatment and were included in the analyses. Between 2010 and 2016, prescribing of antiplatelets and warfarin declined and that of DOACs increased dramatically (from 1 to 32%). Two-thirds of warfarin users experienced poor anticoagulation control. Warfarin and DOACs were associated with lower risks of ischemic stroke (warfarin, hazard ratio [HR] 0.51 [95% confidence interval (CI) 0.36-0.71]; DOACs, HR 0.69 [95% CI 0.51-0.94]) and all-cause mortality (warfarin, HR 0.47 [95% CI 0.39-0.57]; DOACs, HR 0.45 [95% CI 0.37-0.55]) than were antiplatelets. DOACs were associated with a lower risk of ICH than was warfarin (HR 0.53 [95% CI 0.34-0.83]). GIB risks were similar among all groups.
Conclusion: Antiplatelet prescribing and suboptimal warfarin management remain common in Chinese patients with AF at high risk of stroke. DOAC use may be associated with a lower risk of ischemic stroke and all-cause mortality when compared with antiplatelets and with a lower risk of ICH when compared with warfarin.