Non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention in Asian patients with atrial fibrillation: time for a reappraisal

Non-vitamin K antagonist oral anticoagulants (NOACs) have changed the landscape for stroke prevention in atrial fibrillation (AF). Given the huge burden of AF in Asians, more attention to stroke prevention is clearly needed. Aiming to provide an overview and reappraisal of stroke prevention in Asians with AF, we searched MEDLINE for information on NOACs in Asians. In addition, abstracts from national and international cardiovascular meetings were studied to identify unpublished studies. In the 4 recent Phase 3 trials comparing NOACs to warfarin, a consistent pattern is evident. For efficacy endpoints in the comparison of NOACs vs warfarin, a significant reduction in stroke/systemic embolization was seen for dabigatran 150mg [HR 0.45 (0.28-0.72)], with non-significant trends seen for lower stroke/systemic embolization with other NOACs, except edoxaban 30mg. A similar pattern was seen for ischaemic stroke, with a significant reduction for dabigatran 150mg [HR 0.55 (0.32-0.950]. For haemorrhagic stroke, all NOAC regimes, except rivaroxaban 20mg, had significantly lower hazard ratios. No evidence of increased myocardial infarction was found for NOACs. All-cause mortality was significantly lowered amongst Asian patients on edoxaban 60mg compared to warfarin [HR 0.63 (0.40-0.98)] with non-significant trends to lower mortality with dabigatran 150mg, rivaroxaban and edoxaban 30mg. For safety endpoints, all the NOAC regimes, except rivaroxaban 20mg, significantly reduced major bleeding and 'all bleeding' events. Intracranial haemorrhage was consistently lowered by all NOACs. None of NOACs increased gastrointestinal bleeding. These information suggested that NOACs should be preferentially indicated for stroke prevention in Asians with AF.