The gray areas of oral anticoagulation for prevention of thromboembolic events in atrial fibrillation patients

: Thromboembolic events (TEE) associated with atrial fibrillation (AF) are highly recurrent and usually severe, causing permanent disability or, even, death. Previous data consistently showed significantly lower TEE in anticoagulated patients. While warfarin, a vitamin K antagonist, is still used worldwide, direct-acting oral anticoagulants (DOACs) have shown noninferiority to warfarin in the prevention of TEE, and represent, to date, the preferred treatment. DOACs present favorable pharmacokinetic, safety and efficacy profiles, especially among vulnerable patients including the elderly, those with renal dysfunction or previous TEE. Yet, regarding specific settings of AF patients it is unclear whether oral anticoagulation therapy is beneficial, or otherwise it is the maintenance of sinus rhythm, mostly achieved through a catheter ablation-based rhythm control strategy, that prevents the causal complications linked to AF. While it is known that low-risk patients [CHA2DS2-VASc 0 (males), or score of 1 (females)] present low ischemic stroke or mortality rates (<1%/year), it remains unclear whether they need any prophylaxis. Furthermore, the appropriate anticoagulation regimen for those individuals requiring cardioversion, either pharmacologic or electric, as well as peri-procedural anticoagulation in patients undergoing trans-catheter ablation that nowadays encompasses different energies, are still a matter of debate. In addition, AF concomitant with other clinical conditions is discussed and, lastly, the choice of prescribing anticoagulation to asymptomatic patients diagnosed with subclinical AF at either wearable or implanted devices. The aim of this review will be to provide an update on current strategies in the above-mentioned settings, and to suggest possible therapeutic options, finally focusing on AF-related cognitive decline.