Direct oral anticoagulants in the secondary prevention of stroke and transient ischemic attack in patients with atrial fibrillation

In patients with non-valvular atrial fibrillation (NVAF) and history of transient ischemic attack (TIA) or stroke, the rate of vascular events is higher in comparison to patients without history of stroke or TIA. A meta-analysis of direct oral anticoagulants (DOACs) studies, including only patients with history of stroke or TIA, report a significant reduction of 15 % in the rates of composite of stroke and systemic embolism in patients treated with DOACs, compared to those treated with warfarin. Furthermore, a reduction of 14 % for major bleeding, as well as a 56 % reduction for hemorrhagic stroke over a median follow-up of 1.8-2.0 years is reported. The combination of DOACs and antiplatelet agents carries the potential of additive benefits in patients with NVAF and other vascular diseases. However, the rate of major bleeding is higher among patients who receive concomitantly antiplatelet agents, compared to those taking only a single drug category. The risk of major bleeding seems to be higher among patients receiving dual antiplatelet agents, compared to those receiving a single antiplatelet drug. When NVAF is associated with an acute coronary syndrome requiring dual antiplatelet therapy (e.g. coronary angioplasty and stenting), DOACs plus this therapy should be considered. However, this therapy has to be administered for the shortest possible time, according to the patient's haemorrhagic and thrombotic risks, and stent type. When NVAF is associated with carotid stenosis, a single antiplatelet therapy should be considered. Regarding carotid revascularization, it seems preferable to treat these patients with endarterectomy, so to avoid dual antiplatelet therapy, which is generally administered after stenting.