Anticoagulation in patients with low-burden atrial fibrillation: new evidence focussing on device-detected AF.

Stroke, one of the most severe complications of atrial fibrillation (AF), can be prevented by oral anticoagulants in patients with ECG-documented AF and clinical stroke risk factors. Recent controlled trials suggest that reducing the burden of AF, that is, the time spent in AF, can reduce the risk of stroke. Furthermore, stroke rate was slightly lower than anticipated in controlled trials of anticoagulation in screening-detected AF, and substantially lower than expected in patients with device-detected atrial fibrillation (DDAF) and after AF ablation. These data suggest that AF burden modulates the risk of stroke in patients with AF. Based on their high AF burden in observational datasets, anticoagulation remains the default therapy in patients with ECG-documented AF. However, AF burden reduction using rhythm-control therapies emerges as a new treatment strategy for stroke prevention, and there may be a group of patients with such a low burden of AF, for example, patients with DDAF, that the risks of current anticoagulation therapies outweigh their stroke-preventing effects. Patients with DDAF in the absence of ECG-documented AF and without vascular disease appear to be at low risk of thromboembolic events. In patients with DDAF, shared decision-making that considers the presence of vascular disease, potentially the burden of AF if it is very high, and patient preferences currently emerges as good clinical care. More data are needed to robustly define the complex relations between AF burden, phenotypes and stroke risk.