Comparison of continuity index by atrial fibrillation type with the use of active esophageal cooling

Proactive esophageal cooling is FDA cleared to reduce the likelihood of esophageal injury during radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF). Recent data suggest improved long-term freedom from arrhythmia with cooling, which may result from a lower continuity index with cooling that in turn improves the durability of pulmonary vein isolation (PVI).

To measure and compare the continuity index obtained using proactive esophageal cooling in PVI of paroxysmal and persistent AF.

The continuity index was prospectively calculated for PVI cases of paroxysmal and persistent AF performed by 4 providers between June and September 2023. The continuity index was quantified by the lesion placement order, such that each lesion placed that did not border a previous lesion increased the continuity index by 1 unit. Published data have suggested a continuity index below 6 results in optimum long-term isolation, whereas a continuity index above 6 leads to more gaps, less isolation, and greater AF recurrence.

Data from a total of 71 patients were recorded. Mean patient age was 69.8±9.0, with 43% female, and 28 with paroxysmal, 43 with persistent AF. The mean±SD continuity index for PVI was 2.6±3.8. The mean continuity index was similar between paroxysmal (2.9±3.4) and persistent (2.4±3.9) AF patients, and similar for the left pulmonary veins and on the right (Table 1). Only 5% (4) patients had a continuity index above 6 on either side.

The use of proactive esophageal cooling during RF ablation results in attainment of a low continuity index in PVI of both paroxysmal and persistent AF. This may contribute to the higher rates of freedom from arrhythmia seen with active cooling to date.Table 1