OPINION The role of aspirin for stroke prevention in atrial fibrillation

Atrial fibrillation (AF) is a major cause of stroke and thromboembolism, resulting in substantial morbidity and mortality. For the majority of patients with AF, aspirin has a limited role in stroke prevention, being an inferior strategy and not necessarily safer than the anticoagulant warfarin, especially in the elderly. Novel oral anticoagulant drugs, such as oral direct thrombin inhibitors and oral factor Xa inhibitors, might further diminish the role of aspirin for stroke prevention in AF. Nonetheless, aspirin use should continue in the early stages following presentation of a patient with AF and acute coronary syndrome, and after stenting, in combination with oral anticoagulant drugs and clopidogrel, as appropriate. Notably, aspirin combined with clopidogrel shows only modest benefit in stroke prevention compared with aspirin monotherapy in patients with AF who refuse oral anticoagulant drugs (including warfarin), or in those individuals who have difficulties in anticoagulation monitoring, and can be used where bleeding risk is not excessive.