The spatiotemporal electrogram dispersion ablation targeting rotors is more effective for elderly patients than non‐elderly population

Abstract

Background Modulating atrial fibrillation (AF) drivers has been proposed as one of the effective ablation strategies for non‐paroxysmal AF (non‐PAF). However, the optimal non‐PAF ablation strategy is still under debate because the exact mechanisms of AF persistence including focal activity and/or rotational activity, are not well‐understood. Recently, spatiotemporal electrogram dispersion (STED) assumed to indicate rotors in the form of rotational activity is proposed as an effective target for non‐PAF ablation. We aimed to clarify the effectiveness of STED ablation for modulating AF drivers. Methods STED ablation plus pulmonary vein isolation was applied in 161 consecutive non‐PAF patients not undergoing previous ablation. STED areas within the entire left and right atria were identified and ablated during AF. After the procedures, the STED ablation's acute and long‐term outcomes were investigated. Results (1) Despite a more effective acute outcome of the STED ablation for both AF termination and non‐inducibility of atrial tachyarrhythmias (ATAs), Kaplan–Meier curves showed that the 24‐month freedom ratio from ATAs was 49%, which resulted from the higher recurrence ratio of atrial tachycardia (AT) rather than AF. (2) A multivariate analysis showed that the determinant of ATA recurrences was only a non‐elderly age, not long‐standing persistent AF, and an enlarged left atrium, which were conventionally considered as key factors. Conclusions STED ablation targeting rotors was effective in elderly non‐PAF patients. Therefore, the main mechanism of AF persistency and the component of the fibrillatory conduction might vary between elders and non‐elders. However, we should be careful about post‐ablation ATs following substrate modification.