Long-term efficacy of pulsed-field ablation devices in real-world atrial fibrillation patients: a direct comparison between the Farapulse and the Affera ablation systems

Introduction Pulsed-field ablation (PFA) with its characteristic high tissue-selectivity, has recently emerged as a promising alternative to the conventional radiofrequency ablation for the management of atrial fibrillation (AF). This study evaluated the safety and efficacy of two systems using either a pentaspline or a lattice-tip mapping and ablation catheter. Methods Consecutive AF patients undergoing their first catheter ablation using the PFA system were included in the analysis and divided into two groups based on the ablation system used; Group 1: the pentaspline catheter (Farapulse Inc) and Group 2: 9 mm lattice- tip catheter (Sphere-9, AFFERA, Medtronic). All received isolation of pulmonary veins (PVI) and left atrial posterior wall (LAPW). High-dose isoproterenol challenge (up to 30µg/min) was used to disclose triggers in the LAPW by moving the circular mapping catheter along the PW down to the level of coronary sinus, which were targeted. Lower LAPW was defined as the area between the line joining the inferior borders of the inferior PV-encircling lesions and the coronary sinus. Anti-arrhythmic drugs were discontinued after the 2-month blanking period. Arrhythmia-monitoring was performed at 1, 3, 6 and 12 months with clinic visits, interrogation of wearable devices, 12-lead ECG, 7-day Holter monitoring and event recorders. Patients were followed up for up to 1 year. Results A total of 2,389 patients (Gr. 1: 1816 and Gr. 2: 573) were included in the analysis. During follow-up, 309 (17%) patients from group 1 and 57 (10%) patients from group 2 underwent repeat ablation due to arrhythmia recurrence (p <0.001). Mean time to redo ablation was 5.1±2.2 and 5.6±2.3 months for group 1 and 2 respectively. At redo, PV reconnection was observed in 14 (4.5%) patients vs none (0%) in group 1 and 2 respectively (p=0.10). Reconnection in the ‘lower LAPW’ was seen to be significantly higher in group 1 vs 2 (241, 78%) vs 12 (21%) patients in group 2, p <0.001) (Figure 1). New ectopic triggers were detected in the superior vena cava (SVC) (16, 5.18%), lower crista (38, 12.3%), left atrial appendage (LAA) [76, 24.6%] and coronary sinus (CS) [81, 26.2%] in group 1 patients and LAA (19, 33.3%), CS (17, 29.8%), lower crista ( 4, 7%) and SVC (3, 5.2%) in group 2. Conclusion Findings from this study demonstrate a significantly higher success rate with the Affera ablation system. Moreover, among patients undergoing redo procedure, a significantly higher reconnection rate of the lower LAPW was observed in Farapulse cases compared to Affera.