Atrioesophageal Fistula Rates Before and After Adoption of Active Esophageal Cooling During Atrial Fibrillation Ablation.

BACKGROUND: Active esophageal cooling reduces the incidence of endoscopically identified severe esophageal lesions during radiofrequency (RF) catheter ablation of the left atrium for the treatment of atrial fibrillation. A formal analysis of the atrioesophageal fistula (AEF) rate with active esophageal cooling has not previously been performed. OBJECTIVES: The authors aimed to compare AEF rates before and after the adoption of active esophageal cooling. METHODS: This institutional review board (IRB)-approved study was a prospective analysis of retrospective data, designed before collecting and analyzing the real-world data. The number of AEFs occurring in equivalent time frames before and after adoption of cooling using a dedicated esophageal cooling device (ensoETM, Attune Medical) were quantified across 25 prespecified hospital systems. AEF rates were then compared using generalized estimating equations robust to cluster correlation. RESULTS: A total of 14,224 patients received active esophageal cooling during RF ablation across the 25 hospital systems, which included a total of 30 separate hospitals. In the time frames before adoption of active cooling, a total of 10,962 patients received primarily luminal esophageal temperature (LET) monitoring during their RF ablations. In the preadoption cohort, a total of 16 AEFs occurred, for an AEF rate of 0.146%, in line with other published estimates for procedures using LET monitoring. In the postadoption cohort, no AEFs were found in the prespecified sites, yielding an AEF rate of 0% (P < 0.0001). CONCLUSIONS: Adoption of active esophageal cooling during RF ablation of the left atrium for the treatment of atrial fibrillation was associated with a significant reduction in AEF rate.

His-Bundle Pacing for Identifying Optimal Ablation Sites in Patients Undergoing Atrioventricular Junction Ablation: Teaching an Old Dog a New Trick.

BACKGROUND: Atrioventricular (AV) junction (AVJ) ablation is conventionally performed by localizing the His-bundle electrogram (HBE). Identification of HBE in the presence of atrial fibrillation (AF) can be difficult, and can make this simple procedure challenging. In this study, we describe our experience with an alternative approach to localize optimal ablation sites using His-bundle pacing (HBP). METHODS: Between 1/1/2014 and 12/31/2015, we performed 13 AVJ ablations using the standard electrogram-guided approach and 11 ablations using HBP. All cases utilized a long femoral guiding sheath and an 8-mm-tip electrode radiofrequency (RF) energy ablation catheter. Pacing was performed at high output (10 mA at 2 ms) to initially achieve right bundle branch capture. The catheter was withdrawn until a narrow QRS morphology and increased stim-to-QRS time were observed. HBP was confirmed when paced and native QRS were identical in morphology. RF energy was applied at the site of HBP capture until AV block was observed. RESULTS: Baseline characteristics of patients in each arm were not significantly different. Compared with the standard approach, HBP was associated with trends toward lower RF applications (3 vs. 2, P = 0.16) and shorter mean RF time (208 seconds vs. 128 seconds, P = 0.19). CONCLUSION: HBP is an effective technique to identify optimal ablation sites during AVJ ablation and may shorten procedure time. HBP can be used to identify the AV node during AF without recording the His potential. Future studies with larger sample size are needed to better characterize the utility of this technique.