Improving esophageal protection during AF ablation: The IMPACT study

Background Thermal injury to the esophagus is a known complication of ablation for atrial fibrillation (AF) and accounts for most procedure-related mortality. Thermal protection of the esophageal lumen by infusing cold liquid can reduce thermal injury to a limited extent. A method to control the local luminal esophageal temperature is investigated by this study. Objective To investigate the ability of a powerful temperature control device to protect the esophagus from ablation-related thermal injury. Methods A single-center, prospective, double-blinded randomized controlled trial was used to investigate the ability of the ensoETM device to protect the esophagus from thermal injury. This method was compared in a 1:1 randomization to a control group of standard practice utilizing a single-point temperature probe. In the study group, the device was used to keep the luminal temperature at 4°C during radiofrequency (RF) ablation for AF. Endoscopic examination was performed at 7 days post-ablation and esophageal injury was scored. The patient and the endoscopist were blinded to the randomization. Results We recruited 188 patients, of whom 120 underwent endoscopy. Thermal injury to the mucosa was significantly more common in the control group than in those receiving esophageal protection (12/60 versus 2/60; P=0.008), with a trend toward reduction in gastroparesis (6/60 Vs 2/60, p=0.27). There was no difference between groups in RF duration, force, power and combined ablation index (P value range= 0.2-0.9). Procedure duration and fluoroscopy duration were similar (P=0.97, P=0.91 respectively). Conclusion Thermal protection of the esophageal lumen significantly reduces ablation-related thermal injury compared to standard care. This method of esophageal protection is safe and does not compromise the efficacy of the ablation procedure. CONDENSED ABSTRACT Thermal injury to the esophagus causes most ablation-related deaths. We investigated the ability of a powerful method of esophageal temperature control to protect from thermal lesions during ablation, using a double-blinded randomized clinical trial to compare this to standard care. Patients randomised to receive thermal protection experienced significantly fewer lesions to the esophageal mucosa and a trend towards reduction in gastroparesis. Procedure efficacy and efficiency were not compromised.