Don’t add aspirin for associated stable vascular disease in a patient with atrial fibrillation receiving anticoagulation

#### Key points Atrial fibrillation is the commonest cardiac arrhythmia, with increasing prevalence and incidence.1 Adjusted dose oral anticoagulation (such as with warfarin) is the most effective treatment for stroke prevention in high risk patients with atrial fibrillation.2 However, common practice is to add aspirin (or other antiplatelet treatment) to warfarin in atrial fibrillation if there is associated chronic stable coronary or peripheral artery disease.2 This is despite relatively little evidence that adding aspirin to warfarin reduces stroke or other vascular events in patients with atrial fibrillation. I propose here that we should not add aspirin for associated stable vascular disease in a patient with atrial fibrillation receiving anticoagulation, given the lack of evidence for benefit and the potential for harm. Randomised clinical trials in patients with atrial fibrillation using combinations of anticoagulation and aspirin either compared fixed dose (or low intensity, international normalised ratio (INR) <1.5) anticoagulation …