The higher rates of haemorrhage remain poorly understood, but have led to significant undertreatment of nonvalvular AF with anticoagulant drugs in the Asian population [97]. Data from the primary randomized control trials and from secondary meta-analyses, regarding the efficacy and bleeding risks of anticoagulants in Asian subgroups of the RE-LY, ROCKET-AF, J-ROCKET-AF, ARISTOTLE and ENGAGE AF-TIMI 48 trials, have recently been reviewed