Improved 1-year outcomes after active cooling during left atrial radiofrequency ablation

Abstract

Background Active esophageal cooling during pulmonary vein isolation (PVI) with radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF) is increasingly being utilized to reduce esophageal injury and atrioesophageal fistula formation. Randomized controlled data also show trends towards increased freedom from AF when using active cooling. This study aimed to compare 1-year arrhythmia recurrence rates between patients treated with luminal esophageal temperature (LET) monitoring versus active esophageal cooling during left atrial ablation. Method Data from two healthcare systems (including 3 hospitals and 4 electrophysiologists) were reviewed for patient rhythm status at 1-year follow-up after receiving PVI for the treatment of AF. Results were compared between patients receiving active esophageal cooling (ensoETM, Attune Medical, Chicago, IL) and those treated with traditional LET monitoring using Kaplan–Meier estimates. Results A total of 513 patients were reviewed; 253 received LET monitoring using either single or multi-sensor temperature probes; and 260 received active cooling. The mean age was 66.8 (SD ± 10) years, and 36.8% were female. Arrhythmias were 60.1% paroxysmal AF, 34.3% persistent AF, and 5.6% long-standing persistent AF, with no significant difference between groups. At 1-year follow-up, KM estimates for freedom from AF were 58.2% for LET-monitored patients and 72.2% for actively cooled patients, for an absolute increase in freedom from AF of 14% with active esophageal cooling (p = .03). Adjustment for the confounders of patient age, gender, type of AF, and operator with an inverse probability of treatment weighted Cox proportional hazards model yielded a hazard ratio of 0.6 for the effect of cooling on AF recurrence (p = 0.045). Conclusions In this first study to date of the association between esophageal protection strategy and long-term efficacy of left atrial RF ablation, a clinically and statistically significant improvement in freedom from atrial arrhythmia at 1 year was found in patients treated with active esophageal cooling when compared to patients who received LET monitoring. More rigorous prospective studies or randomized studies are required to validate the findings of the current study.

Multicenter analysis of atrioesophageal fistula rates before and after adoption of active esophageal cooling during atrial fibrillation ablation

“…Insulating effects from the pericardial fat, fibrous pericardium, and serous layers minimize cooling in the atrial myocardium so that effective lesions can still be placed,[33] with long-term follow up data confirming no decrease in freedom from atrial arrhythmias at one year with active esophageal cooling compared with LET monitoring. [32] A larger volume of retrospective data further suggests improvement in freedom from arrhythmias with cooling,[42] which may be due to differences in lesion placement sequence with the catheter, enabled by having cooling in place. [43, 44]…”

“…Insulating effects from the pericardial fat, fibrous pericardium, and serous layers minimize cooling in the atrial myocardium so that effective lesions can still be placed, [33] with long-term follow up data confirming no decrease in freedom from atrial arrhythmias at one year with active esophageal cooling compared with LET monitoring. [32] A larger volume of retrospective data further suggests improvement in freedom from arrhythmias with cooling, [42] which may be due to differences in lesion placement sequence with the catheter, enabled by having cooling in place. [43,44] To date, no AEF has yet been identified in a patient treated with active esophageal cooling using a dedicated esophageal cooling device, and only a single pericardio-esophageal fistula has been reported despite over 22,000 RF catheter ablations now completed using this cooling device.…”

Proactive esophageal cooling during laser cardiac ablation: A computer modeling study

“…This effect is also seen in RF ablation, both in mathematical models 10 and in clinical data, where long-term follow-up has shown improvement in freedom from arrhythmia (postablation period in which the patient does not present with evidence of arrhythmia) with the use of PEC. 37,38 The presence of interspersed tissues between the atrial wall and the esophagus (such as the visceral and parietal layers of the fibrous pericardium, the pericardial space and serous fluid, and the pericardial fat), all of which have low or no tissue perfusion, likely contributes to this phenomenon by providing an effective insulating layer between the cooled esophagus and the myocardial tissue (atrial wall) being heated intentionally to induce targeted lesions.…”

Reduced Continuity Index with Proactive Esophageal Cooling Compared to Luminal Temperature Monitoring During Radiofrequency Ablation

“…Cases with LET monitoring were performed by 3 of the 4 operators using proactive esophageal cooling, but this study otherwise followed the same operators with consistent procedural approaches, operating within the same hospital system, and serving the same patient demographic over the time period. Long-term follow-up comparison of procedural outcome is not available for the cases reviewed in this analysis; however, abundant data, including prospective randomized controlled trial data 8 , as well as larger retrospective data from this same site 9 , support the improved efficacy from proactive esophageal cooling, and ongoing randomized trials (NCT04577859) will continue to quantify this effect size.…”

“…The long-term follow-up from the 120 patient IMPACT randomized controlled trial found a 3% (p=ns) absolute improvement, and a 513 patient review found a 14% absolute improvement (p=0.03) in freedom from arrhythmia at one year. 8,9 A potential mechanism for an improvement in long-term freedom from AF with proactive esophageal cooling is via improvement in lesion contiguity, or lesion sequentiality. 2,3 Lesion contiguity has been characterized using the Continuity Index, which is a quantification determined by the number of non-contiguous, or non-adjacent, lesions placed.…”