Abstract 15733: Long-Term Follow-Up of Patients With Paroxysmal Atrial Fibrillation and Severe Left Atrial Scarring: Comparison Between Pulmonary Vein Antrum Isolation Only or PVAI Combined With Either Scar Homogenization or Trigger Ablation

Abstract

Background: Left atrial (LA) scarring, a consequence of cardiac fibrosis is a powerful predictor of procedure-outcome in atrial fibrillation (AF) patients undergoing catheter ablation. We sought to compare the long-term outcome in patients with paroxysmal AF and severe LA scarring/fibrosis identified by 3D mapping undergoing ablation of the pulmonary veins (PVAI) only or PVAI and the entire scar areas (scar homogenization) or PVAI plus ablation of the non-PV triggers. Methods: One-hundred seventy seven consecutive patients with paroxysmal atrial fibrillation and severe left atrial scarring were included in this study. LA scarring was diagnosed by 3D voltage mapping. The degree of scar was described as severe when >60% of the LA area was involved. Non-PV triggers were defined as ectopic triggers originating from sites other than pulmonary veins such as interatrial septum, superior vena cava, left atrial appendage, ligament of Marshall, crista terminalis and coronary sinus. Patients underwent ablation of the pulmonary vein antrum (PVAI) only (n=45, group 1), PVAI extended to the entire scar areas (scar homogenization [n=66, group 2]) or PVAI plus ablation of non-PV triggers (n=66, group 3). Choice of ablation strategy was determined by the operator. Patients were followed up for arrhythmia recurrence with event recorders, ECG and Holter monitoring. Results: Baseline characteristics were not different between the groups (age 63±9 vs 58±10 vs. 60±11 years, p=0.23; male 71%, vs. 72% vs. 73% p= 0.91). After a single procedure, all patients were followed-up for a minimum of two years. The long-term success rate at the end of the follow up was 19% (12 pts) in group 1, 21% (14 pts) in group 2, and 61% (40 pts) in group 3. Kaplan-Meier log-rank test indicated that the cumulative probability of AF-free survival was significantly higher in group 3 (overall log-rank p <0.001, pairwise comparison 1 vs. 3 and 2 vs. 3 was significant at p<0.01). Conclusions: In patients with paroxysmal atrial fibrillation and severe left atrial scarring, PVAI plus ablation of non-PV triggers is associated with significantly better long-term outcome than PVAI alone or when PVAI is combined with scar homogenization.