Beyond recurrence: redefining atrial fibrillation burden as a prognostic and therapeutic endpoint

Atrial fibrillation (AF) has traditionally been classified by episode duration, whereas rhythm control outcomes—via antiarrhythmic drugs or catheter ablation (CA)—have typically been evaluated using a binary approach, with any arrhythmic recurrence lasting over 30 s deemed a failure. Both definitions have notable limitations. Clinical classification often fails to accurately represent the actual time spent in arrhythmia, and AF recurrence following CA does not always correlate well with relevant clinical outcomes. This has driven increasing interest in the concept of AF burden which, although not consistently defined in literature, generally refers to the total percentage of time spent in arrhythmia during the monitoring period. Emerging evidence suggests that AF burden more accurately reflects the impact of CA on symptoms and serves as a valuable prognostic marker, particularly in specific patient subgroups. This review aims to summarise current knowledge on the impact and prognostic value of AF burden, highlighting unsolved issues, such as the absence of a standardised definition and the need for consensus on its use. Additionally, the review underscores the significance of monitoring strategies, highlighting the potential role that wearable devices and artificial intelligence could play in enhancing continuous monitoring in the near future.