Reduced continuity index with proactive esophageal cooling compared to luminal temperature monitoring during radiofrequency ablation.

Background: Proactive esophageal cooling is Food and Drug Administration (FDA) cleared to reduce the likelihood of esophageal injury during radiofrequency ablation for treatment of atrial fibrillation (AF). Long-term follow-up data have also shown improved freedom from arrhythmia with proactive esophageal cooling compared with luminal esophageal temperature (LET) monitoring during pulmonary vein isolation (PVI). One hypothesized mechanism is improved lesion contiguity (as measured by the continuity index) with the use of cooling. Objective: We aimed to compare the continuity index of PVI cases using proactive esophageal cooling with those using LET monitoring. Methods: We calculated the continuity index for PVI cases at 2 different hospitals within the same health system, using a slightly modified continuity index to facilitate retrospective determination from review of recorded cases. The results were then compared between cases using proactive esophageal cooling and those using LET monitoring. Results: Continuity Indices for a total of 236 cases were determined: 118 cases using proactive esophageal cooling and 118 cases using traditional LET monitoring. With proactive esophageal cooling, the average continuity index was 10.6 (5.6 on the left pulmonary vein and 4.9 on the right pulmonary vein). With LET monitoring, the average continuity index was 37.0 (18.7 on the left and 18.3 on the right), for a difference of 26.4 ( Conclusion: Proactive esophageal cooling during PVI is associated with significantly improved lesion contiguity when compared with LET monitoring. This finding may offer a mechanism for the greater freedom from arrhythmia seen with proactive cooling in long-term follow-up.