Asian strategy for stroke prevention in atrial fibrillation

Atrial fibrillation (AF) has become a major health burden in Asia. It is estimated that in year 2050 Asia will have 72 million AF patients, and 2.9 million among them will suffer from AF-associated stroke. Asian AF patients have similar cardiovascular co-morbidities as westerns, and the recently developed CHA2DS2-VASc score remains valid in predicting stroke risk in Asians, outperforming other scoring systems. There is little evidence supporting a role of aspirin in preventing AF-associated stroke in Asians. Warfarin is effective for the prevention of stroke in Asians, but is very difficult to use. Warfarin-induced bleeding events are more common in Asians. Four major clinical trials have been performed to test non-vitamin K antagonist oral anticoagulants (NOACs) vs. warfarin in the stroke prevention in AF. Warfarin produced higher risk of major bleeding and intra-cranial haemorrhage in Asians compared with those in non-Asians, even though anticoagulation intensity was lower in Asians. All these trials consistently demonstrated that NOACs were superior or non-inferior to warfarin. The benefits of NOACs were especially robust in Asians. The relative risk reduction in most of the efficacy endpoints and the safety endpoints was numerically greater in Asians than in non-Asians. There was no evidence of increased risk of gastro-intestinal bleeding associated with NOACs in Asians. Unless in a few conditions when NOACs are contraindicated, NOACs are preferred medications in the stroke prevention for AF in Asians.