Abstract 18083: Long-Term Radio-Frequency Scar Behavior after Ablation of Atrial Fibrillation: Lessons learned from LGE-MRI

Abstract

Background: Long-term left atrial (LA) ablation scar physiology in patients undergoing ablation of atrial fibrillation (AF) is still unknown. We describe the long-term behavior of ablation lesions initiated using radio-frequency energy.

Methods and Results: In this study we included 24 patients (mean age: 68±12) who underwent AF ablation procedure. Patients underwent LGE-MRI 3 months after AF ablation for detection and quantification of LA wall scar. Moreover, patients underwent repeat LGE-MRI at 2 years follow-up. To investigate the LA wall scar, we reconstructed the LGE-MRI into 3D LA image (Figure A, B). Then we segmented the LA surface into 10 regions; left superior pulmonary vein antrum (LSPV), left inferior PV antrum (LIPV), right superior PV antrum (RSPV), right inferior PV antrum (RIPV), posterior, infero-posterior, septum, anterior, left lateral, and right lateral (Figure C, D). We compared the percentage of LA scar in each region 3 months versus 2 years post AF ablation. The total amount of LA scar significantly decreased (14.4±6.4% vs. 12.2±6.3%; p=0.02, Figure E) 2 years after the ablation procedure. Also, significant decrease of LA scar was documented 2 years post ablation in the posterior (36.6±17.2% vs. 26.8±17.1%; p=0.001) and infero-posterior wall region (19.5±15.8% vs. 13.3±10.0%; p=0.02). Scar in other regions except for anterior and left lateral wall (LSPV, LIPV, RSPV, RIPV, septum, and right lateral) showed the tendency of decreasing at 2 years follow-up.

Conclusion: The scar on the LA after AF ablation decreased in almost all regions after 2 years follow up.