Abstract
BACKGROUND: Increased left atrial (LA) size in atrial fibrillation (AF) is associated with AF recurrence following ablation. Limited data exist on pulsed-field ablation (PFA) in patients with persistent atrial fibrillation and dilated LA. PURPOSE: We aimed to analyze the efficacy and safety of PFA in patients with severe LA dilatation (SLAD) (≥50 ml/m2) compared to normal to moderate LA dilatation (NMLAD) (<50 ml/m2) and persistent AF. METHODS: All consecutive patients undergoing AF ablation with the Farapulse system at 14 centers with complete information of left atrial volume index (LAVi) were included. Protocol-directed PVI was delivered using 2 kV with eight applications per vein. Additional lesions were performed at the operator’s discretion. RESULTS: 197 patients with a history of persistent AF and were included in the analysis. Of these, 74 (37.6%) had long-standing persistent AF, 47 (23.9%) were female, the mean age was 65±8 years and the mean LVEF was 54±9%. The mean LAVi was 42.8±14 ml/m2, 51 (25.9%) patients showed SLAD. A 3D mapping system was used in 70 (35.5%) of the cases, a more extensive lesion set than PVI was performed in 157 (79.7%) of cases. Patients with SLAD exhibited a lower LVEF (50±10% vs 56±8%, p=0.0001) and had a higher burden of comorbidities (structural heart disease: 23.5% vs 9.6%, p=0.016; coronary artery disease: 31.4% vs 12.3%, p=0.004; chronic kidney disease: 9.8% vs 2.1%, p=0.028). No differences between groups were found in terms of underlying AF type (long-standing AF: 37.3% vs 37.7%, p=1.00), more extensive lesion set than PVI only (82.4% vs 78.8%, p=0.688) and the use of 3D mapping system (43.1% vs 32.9%, p=0.234). No differences were also found between groups in terms of PFA deliveries outside PVs (19[14-26] vs 18[14-22], p=0.324) or total number of PFA deliveries (52[46-66] vs 49[44-57], p=0.0616), whereas skin-to-skin time (84[61-95] min vs 70[55-85] min, p=0.004) and fluoroscopy time was longer (23[15-31] min vs 17[14-23] min, p=0.001) in patients with SLAD. PVI was achieved in all patients. During a median follow-up of 358[196-402] days, 34 (17.3%) of patients experienced an arrhythmic recurrence after the 90-day blanking period. The proportion of patient with SLAD who experienced a recurrence was similar to the ones with NMLAD (15.7% for SLAD vs 17.8% for NMLAD, p=0.831); increased LA size (continuous LAVi values or LAVi ≥ 50 ml/m2) was not associated to recurrences (hazard ratio=1.09, 95%CI: 0.98 to 1.03, p=0.945 for continuous LAVi values; 0.82, 0.34 to 1.79, p=0.612 for LAVi ≥ 50 ml/m2). No major complications occurred in both groups. CONCLUSION: In our experience, the use of Farapulse PFA system for persistent AF ablation in patients with severe LA dilatation demonstrated safe and effective outcomes, mirroring a comparable pattern observed in patient with normal to moderate LA size.