Impact of Fibrosis Border Zone Characterisation on Fibrosis-Substrate Isolation Ablation Outcome for Atrial Fibrillation.

Atrial fibrillation (AF) is globally the most common type of cardiac arrhythmia and is a precursor for serious conditions such as stroke. The success rate of AF treatments, such as catheter ablation (including the current gold standard, pulmonary vein isolation), is suboptimal, warranting better strategies. Fibrosis-substrate isolation ablation (FISA) is a promising new ablation strategy currently showing success in clinical trials. However, to perform FISA, the left atrial (LA) fibrosis border zone (FBZ) needs to be characterised. This study investigates the impact of FBZ characterisation on FISA outcomes for AF simulated using 10 patient-specific 3D LA models. Simulations show that (i) including a large amount of FBZ tissue within FISA lesions can increase the success of AF termination, and (ii) FISA is more effective for patients with Utah fibrosis stages III and IV. These results can help clinicians to improve the stratification of AF patients and the implementation of the FISA strategy.