Subclinical atrial fibrillation/atrial high-rate episodes: what significance and decision-making?

Abstract

Subclinical atrial fibrillation (AF) and atrial high-rate episodes (AHREs) are often detected incidentally through cardiac implantable electronic devices or wearables, especially in asymptomatic patients. These episodes pose a clinical challenge as they are associated with an increased risk of stroke, albeit at a lower rate compared with clinical AF. This review discusses the evolving understanding of AHRE, highlighting the uncertainties regarding optimal management, particularly the use of oral anticoagulants. Two key trials, ARTESiA and NOAH-AFNET 6, investigated anticoagulation in patients with device-detected AHRE. ARTESiA found that apixaban significantly reduced stroke or systemic embolism, but with an increased risk of major bleeding. In contrast, NOAH-AFNET 6, which tested edoxaban, did not demonstrate a significant benefit in reducing cardiovascular events but also observed higher bleeding rates. A meta-analysis of these trials confirmed the efficacy of oral anticoagulants in lowering ischaemic stroke risk, though with an elevated bleeding risk. Given these findings, clinical decision-making in patients with AHRE must be individualized, taking into account stroke risk, bleeding risk, and patient preferences. Shared decision-making is crucial to balance the benefits and risks of anticoagulation, especially in the context of progression to clinical AF and its associated stroke risk. Moreover, it is essential to educate patients about the risk of bleeding complications and emphasize the importance of close monitoring. Future research may further clarify optimal anticoagulation strategies and better define high-risk subgroups that would most benefit from therapy.