An international two-centre experience with the third generation laser balloon system: safety, efficiency, and efficacy

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Endoscopic laser balloon systems (ELBS) are a new tool for pulmonary vein isolation (PVI). The third generation ELBS underwent significant structural improvements compared to its predecessors. These include a novel feature (RAPID mode), potentially allowing an automized and high-speed circumferential energy delivery for PVI. However, there is a lack of data on its use. OBJECTIVE: We analyzed the safety, efficiency, and efficacy of the third-generation ELBS in a cohort of patients who underwent ablation of atrial fibrillation in a German and an Italian centre. METHODS: We prospectively enrolled all consecutive patients who underwent PVI using the third-generation ELBS between June 2019 and November 2022. All the procedures were performed by four operators. For each pulmonary vein (PV), we always attempted to obtain a complete circumferential lesion using only the RAPID mode. When this was not feasible, the operator treated the remaining gaps with point-by-point laser delivery. RESULTS: We included 163 patients in our study (mean age 61.9 ± 11.4, persistent atrial fibrillation 30.6%, female patients 30.6%). The operators identified and successfully isolated 655 pulmonary veins. There was an anatomical variation of the PVs in 41 (25.1%) patients, of whom 19 had either a left or a right common trunk, and 23 had a supernumerary right PV. 424 PVs (64%) were isolated for at least 80% of their circumference using the RAPID mode, 389 (59.4%) were treated using it for a minimum of 90% of their circumference, and finally, 289 (44%) were isolated using only RAPID. The operators could perform the procedure using only the RAPID mode in 35 (21.5%) patients. We observed a mean total procedural and fluoroscopic times of 95.7 ± 44.5 min and 13.9 ± 8.4, respectively. 5 (3%) periprocedural complications occurred. There were three episodes of transient phrenic nerve palsy (the most extended episode resolved two months after discharge). One episode of pericardial tamponade occurred, with a subsequent need for pericardiocentesis. Finally, there was one periprocedural transient ischaemic attack (TIA). During energy delivery, eight pinhole balloon ruptures occurred. Eighty-five patients were followed up for at least six months (mean follow-up 12.2 ± 4.4 months). Among these, 26 (30.5%) presented a recurrence after the blanking period. Among baseline features, persistent AF was not a predictor of recurrence. CONCLUSION: This is one of the largest cohorts of patients treated with third-generation ELBS. In our two-centre experience, the system proved efficient, safe, and effective and the RAPID mode showed good applicability.