Abstract 18054: Left Atrial Structural Remodeling Occurs in Every Region in the Left Atrium and Determines the Recurrence after Atrial Fibrillation Ablation

Abstract

Background: Left atrial structural remodeling (LASRM) can be detected using LGE-MRI in patients with atrial fibrillation (AF). In this study, we analyzed the distribution of SRM within the various LA regions and it’s impact on ablation procedure outcome.

Methods: We included 160 patients (mean age: 66±11) who underwent AF ablation in this study. We performed pre-ablation LGE-MRI to detect the LASRM and reconstructed the LGE-MRI into 3D LA image (Figure A, B). Then we segmented the LA surface into 9 regions (left PV antrum, right PV antrum, posterior, infero-posterior, septum, anterior, LA appendage, left lateral, and right lateral; Figure C, D). We correlated the degree of pre-ablation LASRM in each region with the recurrence of AF.

Results: AF recurrence was recognized in 58 of 160 patients after the initial ablation. Patients with recurrence had significantly more LASRM (enhancement out of total LA region) in every area compared with patients without recurrence (left PV antrum [2.5±1.2% vs. 1.9±1.2%; p=0.004], right PV antrum [1.5±1.3% vs. 0.8±0.8%; p=0.0003], posterior [3.4±2.0% vs. 2.2±1.6%; p<0.0001], infero-posterior [1.9±1.7% vs. 1.3±1.5%; p=0.03], septum [1.1±1.2% vs. 0.6±0.9%; p=0.002], anterior [3.5±2.6% vs. 2.1±2.1%; p=0.0005], LA appendage [1.3±1.5% vs. 0.7±1.0%; p=0.003], left lateral [3.5±2.3% vs. 2.4±1.9%; p=0.002], right lateral [0.3±0.3% vs. 0.1±0.3%; p=0.003], Figure E).

Conclusion: The LASRM occurs in every region of the LA in patients with AF. Procedural failure seems to correlate with the degree of LASRM across all regions of the LA.