Impact of esophageal cooling versus temperature monitoring on safety and procedural parameters during radiofrequency ablation of atrial fibrillation: A single-center experience in Germany

Background

Heat-induced (peri)esophageal injury is a potential complication during radiofrequency (RF) ablation of atrial fibrillation (AF). Over time, several techniques have been developed to mitigate this risk; however, none have completely eliminated it.

Active esophageal cooling has shown to reduce the incidence of esophageal injury, likely through dissipation of heat and inhibition of inflammation. In contrast, established luminal esophageal temperature (LET) monitoring detects local heating but, by design, does not actively prevent tissue damage.

Purpose

To compare procedural characteristics and esophageal safety between RF-based AF ablation using either active esophageal cooling or LET monitoring.

Methods

We analyzed two chronologically distinct cohorts of patients undergoing RF ablation for AF at our Medical University. Esophageal protection was achieved using either LET monitoring (S-Cath; n= 200; 08/2018–08/2023), or closed-loop active esophageal cooling (ensoETM; n=153; 08/2023–10/2025).

Esophageal injury was assessed by endoscopy within 24–72 hours after pulmonary vein isolation and – for the purpose of this study - defined as the presence of mucosal lesions (erosion or ulcer) and/or new-onset food retention as a sign of periesophageal vagal nerve injury.

Results

Baseline characteristics were comparable between both cohorts [Figure 1]. Average RF-power and contact force were significantly higher in the cooling group, while both total procedure and fluoroscopy times were shorter.

Mucosal esophageal lesions occurred twice as often in the LET group (hereof, ulcers in 42% with LET vs. 22% with cooling; *p < 0.05). No significant difference was observed in the rate of food retention [Figure 2].

Conclusion

Compared with luminal temperature monitoring, active esophageal cooling significantly reduces mucosal esophageal injury but not periesophageal vagal nerve injury, while also shortening procedure duration - possibly reflecting operators’ increased confidence in esophageal safety when cooling is used.

Although emerging technologies such as pulsed field ablation (PFA) may eliminate the risk of thermal esophageal injury, RF ablation remains widely used, underscoring the need for effective esophageal protection strategies.Baseline and procedural characteristicsEndoscopy following PVI