Subclinical Atrial Fibrillation: Definition, Prevalence, and Treatment Strategies
The burden of atrial fibrillation will grow as our population ages and the presence of comorbidities, such as hypertension and obesity, increases. The detection of subclinical atrial fibrillation remains an active area of research, and defining the optimal time when stroke risk increases remains to be determined. The optimal detection strategy is also under active evaluation, as novel technologies, from handheld devices, to watches, to implantable monitors, are now available and may facilitate the detection of subclinical atrial fibrillation. Subclinical atrial fibrillation can be defined as asymptomatic, intermittent atrial fibrillation detectable by surveillance beyond that provided by routine clinical care. It is associated with an increased risk of stroke. Placement of electrocardiographic monitoring devices in patients without a prior diagnosis of atrial fibrillation to detect subclinical atrial fibrillation and to inform anticoagulation treatment decisions has been proposed as a strategy that might improve patient outcomes. At present, however, we do not have evidence that placing, implanting, and/or using a device to detect atrial fibrillation or initiating anticoagulation among those in whom it is detected is beneficial. Ongoing trials, such as ARTESiA and NOAH, will evaluate the efficacy and safety of oral anticoagulant therapy in patients with subclinical atrial fibrillation.