An international multicentre experience with the third-generation laser balloon system: safety, efficiency, and efficacy
Authors: Bartoli L , Martignani C , Spadotto A , Giacopelli D , Giaccardi M , Mircapillo G , Forleo G B , Giomi A , Arena G , Ciconte G , Pappone C , Montemerlo E , Rovaris G , Heeger C H , Tilz R R 
Published: May 2024

Abstract

Background
Pulmonary vein isolation (PVI) with the use of an endoscopic laser balloon (ELB) is an alternative option for catheter ablation of atrial fibrillation (AF). The third-generation system has several improvements, including the novel RAPID mode (RM), potentially allowing a one-shot, continuous, circumferential laser lesion for PVI.

Objective
In an international, multicentric cohort, we assessed the third-generation ELB’s safety, efficacy, and long-term effectiveness. We also focused on the learning curve (LC) and the use of RM.

Methods
Between June 2019 and December 2022, we prospectively obtained data on all the patients who consecutively underwent ablation of AF using the third-generation ELB in eight Italian and one German hospital. Each operator attempted to use the RM to the maximum extent in every procedure. Follow-up (FU) visits were scheduled at 3, 6, 12 and 24 months and included a Holter-ECG of 24 hours or, if the patient was a carrier, a device interrogation (implantable loop recorder or two-chamber/three-chamber pacemaker/defibrillator). For FU analysis, we included patients with data available after the blanking period (the first 90 days after the procedure). We analysed the LC, comparing the outcomes of the first fifteen patients of each centre with the remaining patients. In addition, we investigated the impact of an extensive use of the RM (at least 90% of all PV circumferences) on the procedural and FU outcomes.

Results
we enrolled 427 patients. Of these, 328 had a FU &gt;90 days. The mean total procedural and fluoroscopic times were 105 (66-150) and 17 (10-28) minutes, respectively. Serious adverse procedural events occurred in 11 patients (2.6 %) as follows: 3 periprocedural transient ischaemic attacks, 4 pericardial tamponades, 1 persistent phrenic nerve palsy and 3 severe vascular complications. The mean FU period was of 365 days (194-533). AF recurrence-free rate was 76.7% (95% CI, 70.8%-81.5%) at 12 months. Median RM use was 94% (81-100) of the PVs circumference. RM could be used for at least 90% of all PV circumferences in 188 (55.8%) patients, and the operators could perform an RM-only procedure in 82 (24.3%) patients. Patients treated after the LC or with extensive use of RM showed significantly reduced procedural times and rates of AF recurrence. In a multivariate analysis, the use of the RM was not an independent predictor of a lower recurrence rate at FU, demonstrating only a tendency toward significance (86.0% [77.3-91.6] vs 71.3% [61.3-79.2], HR 0.52, CI 0.26-1.07, p 0.075).

Conclusion
In this prospective, multicentre, international registry of patients treated with the third-generation ELB, the system proved efficient, safe, and effective. Completing the LC and using the RM reduced procedural time and arrhythmia recurrence. However, using RM was not an independent predictor of a lower recurrence rate.