Differences in the feasibility, anatomical parameters predicting procedural difficulty, and isolation area of a left atrial posterior wall isolation using radiofrequency versus cryoballoon catheters

Backgrounds The difficulty and outcome of the adjunctive left atrial posterior wall isolation (LAPWI) in patients with persistent atrial fibrillation (PersAF) may be affected by the ablation energy used. This study aimed to compare the completion rate, anatomical parameters predicting procedural difficulty, and the isolation area of a LAPWI between the use of radiofrequency (RFA) and cryoballoon ablation (CBA). Methods We enrolled 95 and 93 patients with PersAF who underwent pulmonary vein isolation (PVI)+LAPWI using RFA (RF group) and CBA (CB group), respectively. Preoperative computed tomography was used to evaluate the anatomical features associated with an incomplete LAPWI. Post‐ablation 3‐dimensional maps were analyzed to quantify the isolation area. Results The completion rate of the LAPWI was significantly higher in the RF group than the CB group without touch‐up RFA (88.4% vs. 72.0%; p = .005). Predictors of incomplete LAPWI were a longer left inferior pulmonary vein (LIPV)‐esophageal distance ( p < .001) for RFA and a steeper angle of the LAPW ( p < .001) and longer transverse LAPW diameter ( p = .016) for CBA. The isolated non‐PV area with RFA or CBA alone was significantly greater in the CB group than the RF group (27.5 ± 9.5 cm 2 vs. 22.9 ± 6.9 cm 2 ; p < .001). Conclusion The position of the esophagus at a distance from the LIPV was associated with an incomplete LAPWI using RFA, while a steeper angle of the LAPW and transverse enlargement of the LAPW were associated with that using CBA. The completion rate of the LAPWI was higher with RFA, but the isolation area outside of the PVs was greater with CBA.