Utility of Esophageal Cooling Therapy for the Prevention of Thermal Injury During Atrial Fibrillation

ABSTRACT Atrial fibrillation (AF) is the most common type of heart arrhythmia; an estimated 2.7 to 6.1 million people in the United States have been diagnosed with AF and this number is expected to increase. Cardiac catheter ablation is an effective AF treatment and is performed up to a quarter million times per year in the US; however, safety concerns exist. Endoscopically detected esophageal lesions (EDELs) occur in 15-40% of cases and can progress into serious injuries, including atrioesophageal fistula (AEF), which is fatal in most cases. Current prevention strategies include reducing ablation energy applied to the left atrium, monitoring esophageal temperature, and mechanically displacing the esophagus. None of these methods have demonstrated reproducible clinical effectiveness in preventing or reducing severe EDELs or AEF. Previous studies have shown that active cooling reduces thermal esophageal injury but challenges in clinical implementation limited commercialization of this approach. The ensoETM, originally designed and successfully commercialized for whole-body temperature modulation by Attune Medical using SBIR seed funding provides the first scalable solution for active esophageal cooling during cardiac ablation. The ensoETM device is a novel device FDA- cleared for core temperature modulation using a multi-lumen silicone tube placed in the esophagus to cool or warm a patient. During radiofrequency (RF) ablation procedures, the ensoETM device acts as a heat sink for RF energy inadvertently delivered to the esophagus, thus minimizing unwanted tissue damage. Pilot randomized, controlled studies show a large and consistent effect size, and suggest benefits in efficiency and fluoroscopy reduction as well, warranting larger, multi-site investigation. The Specific Aims of this project are: 1) Determine the occurrence rate of esophageal thermal injury and compare the severity of esophageal injury between groups with and without ensoETM; 2) Measure the impact of ensoETM on procedural efficiency and fluoroscopy use; 3) Determine specific ensoETM design changes and cooling protocol changes necessary for optimization. Demonstration of these aims will pave the way for commercialization of this innovative approach to esophageal protection, and support an expanded FDA label claim, making catheter ablation safer for the hundreds of thousands of people who currently undergo AF ablation per year, and expanding an alternative to expensive and life-long pharmaceutical treatment.