P1419
Persistent atrial fibrillation terminates during ablation more often using dispersion mapping than with fractionated electrogram mapping

Persistent AF termination rates have increased since the advent of AF driver mapping, with a recent meta-analysis (Baykaner Circ AE 2018) of over 3200 patients showing improved 12 month freedom from AF/AT.  However,  recent randomised clinical trials have cast doubt on the efficacy of complex fractionated atrial electrograms (CFAE) based mapping strategies. We

set out to study a consecutive single centre series pre-and post- use of spatio-temporal dispersion (STD) to identify termination rates between the two approaches.

We recruited consecutive patients over 18 months at a single high volume tertiary centre undergoing first redo ablation for persistent AF. Patients were all

mapped using Pentarray to mark areas of substrate using the spatio-temporal dispersion (STD) method (Seitz JACC 2017).

Ablation was performed by a single operator using catheters to standardise equipment and workflow, to enable true

comparison of mapping and ablation results in a consecutive series.

In total 38 patients were studied at redo ablation for persistent AF (age 69, 87% male, LA diameter 4.5cm). Termination of persistent

AF to SR (30%) or AT (70%) was obtained in 30/38 (79%) of the group with STD based substrate ablation vs. 1/38 (3%) in patients mapped

with CFAE targeting using identical equipment and operator (p < 0.001). Procedure time was no different between STD and CFAE based

approaches (263 vs. 248 mins, p = ns). Figure shows STD patterns (red arrows) on Pentarray in a 67 year old man anterior to left inferior

pulmonary vein (A), where ablation terminated AF to sinus rhythm. At 12 month follow up, 30/38 (79%) patients were in sinus rhythm with no AF detected on ECG or continuous monitoring.

In this single centre series of persistent AF ablations, the use of STD mapping increased rates of termination compared to a fractionation based mapping strategy alone, without increasing overall procedure time. Clinical outcome data suggest this translates into better 12 month clinical outcomes, and motivate prospective randomised trials to definitively study this technique.

Abstract Figure.