Racial variation in clinical outcomes among patients with atrial fibrillation (AF) receiving anticoagulation therapy remains an important consideration in optimizing treatment strategies. In a pooled patient-level analysis of four pivotal randomized trials published in the European Heart Journal, baseline characteristics and outcomes were compared between Asian and non-Asian populations, and the relative efficacy and safety of direct oral anticoagulants (DOACs) versus warfarin were assessed.
The dataset included 10,212 Asian and 61,471 non-Asian patients. Asians were younger by a mean of 3.2 years, had lower body weight by approximately 20 kg, lower renal function (mean creatinine clearance 64.9 vs 77.3 mL/min), and a higher prevalence of prior stroke or transient ischemic attack (37.2% vs 26.6%; p<0.001 for all). In the warfarin arm, time in therapeutic range was lower among Asians (57.7% vs 66.2%; p<0.001), and Asians had higher adjusted risks of stroke or systemic embolic events (SEE), major bleeding, intracranial hemorrhage, gastrointestinal bleeding, and primary net clinical outcome.
Compared with warfarin, standard-dose (SD) DOACs were associated with lower risks of stroke/SEE (HR 0.65 [0.53-0.80] vs 0.86 [0.78–0.95]), major bleeding (HR 0.62 [0.52-0.75] vs 0.91 [0.84–0.98]), and primary net clinical outcome (HR 0.76 [0.68–0.85] vs 0.94 [0.90-0.98]), with greater relative risk reduction in Asians than non-Asians (Pint<0.02). Gastrointestinal bleeding risk was not increased in Asians (HR 0.92 [0.69-1.23]) but was higher in non-Asians (HR 1.41 [1.25-1.58]; Pint=0.009). Lower-dose DOACs were associated with increased risks of stroke/SEE and adverse composite outcomes in Asians.
Overall, standard-dose DOACs were associated with lower risks of thromboembolic and bleeding outcomes compared with warfarin, with greater relative risk reduction observed in Asian populations. These findings indicate more favorable clinical outcomes with standard-dose DOACs in Asian patients with AF and may inform anticoagulant selection in this population.
