Co-Author(s):
ahmed ElBatran, MD
Abhay Bajpai, MD - St. George’s NHS Trust
Zia Zuberi, PhD - St. George’s NHS Trust
Anthony Li, MD - St. George’s NHS Trust
Mark Norman, PhD
Riyaz Kaba, MD - St. George’s NHS Trust
Manav Sohal, MD - St. George’s NHS Trust
Zaki Akhtar, MRCP
Banu Evranos, MD
Hanney Gonna, MRCP
Idris Harding, PhD
Nawaf Al Subaie, PhD
Jamal Hayat, MD - St. George’s NHS Trust
John Louis-Auguste, MD - St. George’s NHS Trust
Mark Gallagher, MD - St. George’s NHS Trust
SGUL
Blackshaw Road, London, SW170QT
Introduction | Objectives: The IMPACT study established the role of controlled esophageal cooling in preventing thermal injury during radiofrequency (RF) ablation for atrial fibrillation (AF) guided by Ablation Index (AI). The effect of esophageal cooling on ablation delivery and acute outcomes had not been previously studied.  Objective: To determine the effect of esophageal cooling on the formation of RF lesions, the ability to achieve procedural endpoints and the characteristics of RF lesions associated with esophageal injury.
Methods: AF ablation was guided by AI (30W at 350-400 AI posteriorly, 40W at 450 AI anteriorly). A blinded 1:1 randomization assigned patients to the use of ensoETM® device to keep esophageal temperature at 4 degrees during ablation or standard practice using a single-sensor temperature probe. Ablation parameters and short-term outcomes were analysed.
Results: We recruited 188 patients. 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). Procedure and fluoroscopy times were similar. First pass pulmonary vein isolation and reconnection at the end of the waiting period were similar in both randomized groups (51/64 vs 51/68; p=0.54 and 5/64 vs 7/68; p=0.76, respectively). Posterior wall isolation was also similar: 24/33 vs 27/38; p=0.88. Ablation effect on tissue, measured in impedance drop, was also similar: 8.6Ω (IQR: 6-11.8) vs 8.76Ω (IQR: 6-12.2; p=0.25). Arrhythmia recurrence was similar at 6 months and 12 months (p >0.05).
Conclusions: Esophageal cooling has been shown to be effective in reducing ablation-related thermal injury during RF ablation. AI data show that this protection does not make it any more difficult to achieve standard procedural endpoints or clinical success in the short and mid term.