Pulmonary Vein Isolation Versus Left Atrial Posterior Wall Isolation with the Cryoballoon Using the Cross-Over Technique in Persistent Atrial Fibrillation

BackgroundThe cryoballoon (CB) has recently been used for performing pulmonary vein isolation (PVI) with concomitant left atrial posterior wall isolation (LAPWI). However, successful LAPWI using only the CB is technically challenging. This study aimed to evaluate the feasibility, safety, and efficacy of the cross-over technique, wherein an overlapped ablation is performed by placing the CB from both left and right directions in contact with the roof and bottom of the left atrium (LA). MethodsThis was a single-center, retrospective, observational study of 194 consecutive patients with persistent atrial fibrillation (PerAF) who underwent a first-time procedure of PVI + PWI (108 patients) or PVI-only (86 patients) using the CB between April 2021 and December 2023. The cross-over technique was applied in all LAPWI using the CB. ResultsFor ablation of the LA roof and bottom, respectively, a mean of 8.6 {+/-} 1.0 (L[-&gt;]R 4.3 {+/-} 1.1 and R[-&gt;]L 4.3 {+/-} 1.1) and 9.1 {+/-} 1.2 (L[-&gt;]R 4.5 {+/-} 1.2 and R[-&gt;]L 4.6 {+/-} 1.6) CB applications were delivered. LAPW was successfully isolated solely using CB in 107 patients (99.1%). The PVI + PWI group, compared to the PVI-only group, had significantly longer procedure time (180.0 {+/-} 42.4 vs. 78.0 {+/-} 22.1 min, P < 0.001). No severe adverse events were observed in either group. During a median follow-up of 19 months, 93.5% and 72.9% of the PVI + PWI and PVI-only groups, respectively, were free from all atrial tachyarrhythmia recurrence (P = 0.011). Cox regression analyses showed LA diameter and PVI + PWI were independent predictors of all atrial tachyarrhythmias recurrence. ConclusionsLAPWI performed solely with the CB using the cross-over technique is feasibly, safe, and was independently associated with a significantly higher freedom from recurrence of atrial tachyarrhythmias compared with PVI alone on midterm follow-up in patients with PerAF. WHAT IS KNOWN?O_LIThe cryoballoon (CB) has recently been used for performing pulmonary vein isolation (PVI) with concomitant left atrial posterior wall isolation (LAPWI). LAPWI using the CB was previously demonstrated to be superior to PVI alone for the treatment of persistent atrial fibrillation (PerAF). C_LIO_LIHowever, successful LAPWI using only the CB is technically challenging, and there is no established LAPWI technique or protocol using the CB. C_LI WHAT THE STUDY ADDS?O_LILAPWI solely with the CB was successfully performed using the cross-over technique, wherein an overlapped ablation was performed placing the CB from both left to right and right to left directions in contact with the roof and bottom of the LA. C_LIO_LIThis technique achieved a high rate of acute success (99.1%) and freedom from recurrence of atrial tachyarrhythmias (93.5%) on a midterm follow-up without increasing adverse events. C_LIO_LIThe cross-over technique could be considered an effective ablation strategy for LAPWI, especially in difficult cases such as narrow and steeply angled LA roof and bottom. C_LI