Acute termination as an endpoint in individualised electrophysiological substrate ablation in persistent atrial fibrillation

Abstract

Abstract Background Individualised electrophysiological substrate ablation in persistent atrial fibrillation (perAF) is complicated by the lack of a clearly defined procedural endpoint. The frequency of acute termination and its association with long-term outcomes is not well described. Purpose To define the frequency of acute termination with ablation in a cohort of patients with perAF undergoing catheter ablation with a non-contact charge density mapping (CDM) system and assess its correlation with long term outcomes. Methods The DISCOVER registry (NCT03893331) contains patients recruited to an ongoing multicenter, observational study of CDM guided endocardial ablation procedures. We searched the U.K. component of this registry for all patients presenting for perAF ablations to extract the necessary data for analysis. Termination was considered secondary to ablation whether occurring directly from AF, or via an organized atrial tachycardia (AT). Follow up was performed at 6 and 12 months, and included patient reported recurrence, standard 12-lead ECG, and 7-day ambulatory ECG. Results Eighty-six patients were analysed. All presented in AF at the start of their procedure. Termination was with ablation in 18 (21%). Six-month follow up data was available in 80 (93%), and 12-month in 71 (83%) patients. Freedom from AF was significantly higher in patients ablated to termination; at 6-months 82% vs 51% (p=0.02), at 12-months 69% vs 40% (p=0.04) [figure 1]. Rates of AT during follow up were similar between both groups; at 6-months 24% vs 25% (p=0.93), at 12-months 46% vs 33% (p=0.38) in ablation to termination vs no acute termination groups respectively. Conclusion Occurring in approximately 1/5th of our cohort, the value of ablation to termination as a marker of procedural endpoint may be limited; however, it is a predictor of favorable outcomes. Furthermore, there is no indication from our analysis of a hypothetical association with larger volumes of substrate modification and subsequently development of AT.Freedom from AF at 6 and 12 months