Procedural findings and ablation outcome in patients with atrial fibrillation referred after two or more failed catheter ablations.

INTRODUCTION: This study reports the procedural findings and ablation outcome in AF patients referred after ≥2 failed PV isolation (PVI). METHODS: Three hundred and five consecutive AF patients referred after ≥2 PVI were included in the analysis. High-dose isoproterenol challenge was used to identify PV reconnection and non-PV triggers; the latter were ablated based on the operator's discretion during the index procedure. At the repeat procedure, non-PV triggers were ablated in all. Empirical isolation of LA appendage (LAA) and coronary sinus (CS) was performed if the PVs were silent and no non-PV triggers were detected. RESULTS: PV reconnection was detected in 226 and non-PV triggers were identified or empirically isolated in 285 patients during the index procedure. At follow-up, 182 (60%) patients were recurrence-free off-AAD; the success rate with and without non-PV ablation was 81% vs. 8% (P < 0.0001). 104 patients underwent repeat procedure with non-PV trigger ablation in all. At 1 year, 90% were arrhythmia free off-AAD in non-PV ablation group, and 72% who did not receive non-PV triggers ablation at the index procedure (P = 0.035). The success rate of empirical LAA and CS isolation was 78.5% and 82% after the index and repeat procedure, respectively. CONCLUSION: In patients experiencing AF recurrence after multiple failed PVI, despite PV reconnection, non-PV triggers were found to be responsible for AF maintenance in the majority and ablating those triggers increased ablation success. Additionally, in the presence of permanent PVI and no non-PV triggers on isoproterenol, empirical isolation of LAA and CS provided high rate of arrhythmia-free survival.

Prevalence of right atrial non-pulmonary vein triggers in atrial fibrillation patients treated with thyroid hormone replacement therapy.

BACKGROUND: Thyroid hormone (TH) is known to enhance arrhythmogenicity, and high-normal thyroid function is related with an increased recurrence of atrial fibrillation (AF) after catheter ablation. However, the impact of thyroid hormone replacement (THR) on AF ablation is not well known. METHODS: This study evaluated 1163 consecutive paroxysmal AF patients [160 (14%) on THR and 1003 (86%) without THR] undergoing their first catheter ablation. A total of 146 patients on THR and 146 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model (age, sex, body mass index, and left atrium size). The presence of non-pulmonary vein (PV) triggers was disclosed by a high-dose isoproterenol challenge (up to 30 µg/min) after PV isolation. RESULTS: Clinical characteristics were not different between the groups. When compared to the control, non-PV triggers were significantly greater in the THR patients [112 (77%) vs. 47 (32%), P < 0.001], and most frequently originated from the right atrium (95 vs. 56%, P < 0.001). Other sources of non-PV triggers were the interatrial septum (25 vs. 11%, P = 0.002), coronary sinus (70 vs. 52%, P = 0.01), left atrial appendage (47 vs. 34%, P = 0.03), crista terminalis/superior vena cava (11 vs. 8%, P = 0.43), and mitral valve annulus (7 vs. 5%, P = 0.45) (THR vs. control), respectively. After mean follow-up of 14.7 ± 5.2 months, success rate was lower in patients on THR therapy [94 (64.4%)] compared to patients not receiving THR therapy [110 (75.3%), log-rank test value = 0.04]. CONCLUSIONS: Right atrial non-PV triggers were more prevalent in AF patients treated with THR. Elimination of non-PV triggers provided better arrhythmia-free survival in the non-THR group.

Long-term follow-up of patients with paroxysmal atrial fibrillation and severe left atrial scarring: comparison between pulmonary vein antrum isolation only or pulmonary vein isolation combined with either scar homogenization or trigger ablation.

AIMS: 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 (PAF) and severe LA scarring identified by 3D mapping, undergoing pulmonary vein isolation (PVAI) only or PVAI and the entire scar areas (scar homogenization) or PVAI+ ablation of the non-PV triggers. METHODS AND RESULTS: Totally, 177 consecutive patients with PAF and severe LA scarring were included. Patients underwent PVAI only (n = 45, Group 1), PVAI+ scar homogenization (n = 66, Group 2) or PVAI+ ablation of non-PV triggers (n = 66, Group 3) based on operator's choice. Baseline characteristics were similar across the groups. After first procedure, all patients were followed-up for a minimum of 2 years. The success rate at the end of the follow-up was 18% (8 pts), 21% (14 pts), and 61% (40 pts) in Groups 1, 2, and 3, respectively. Cumulative probability of AF-free survival was significantly higher in Group 3 (overall log-rank P <0.01, pairwise comparison 1 vs. 3 and 2 vs. 3 P < 0.01). During repeat procedures, non-PV triggers were ablated in all. After average 1.5 procedures, the success rates were 28 (62%), 41 (62%), and 56 (85%) in Groups 1, 2, and 3, respectively (log-rank P< 0.001). CONCLUSIONS: In patients with PAF and severe LA scarring, PVAI+ ablation of non-PV triggers is associated with significantly better long-term outcome than PVAI alone or PVAI+ scar homogenization.