Purpose: Catheter ablation is less successful for non-paroxysmal atrial fibrillation (NPAF) according to numerous follow-up studies. The choice of ablation strategy for patients with NPAF remains controversial. The objective of the study was to explore the clinical efficacy of the "ICE-FIRE" ablation.
Methods: Ninety NPAF patients were enrolled. Patients were randomly divided into RF (treated with circumferential pulmonary vein isolation (CPVI) and additional substrate modification by radiofrequency ablation) group and I-F (treated with CPVI by cryoablation and additional substrate modification by radiofrequency ablation) group. After CPVI and cardioversion to sinus rhythm, high-density mapping was performed. Eight-one of 90 participants restored to sinus rhythm. Seventy-four of 81 NPAF patients showed low-voltage zone. Substrates with low-voltage zone were targeted for further modification. Participants were followed at baseline, 3, 6, 9, and 12 months after the initial ablation.
Results: The I-F group shared more X-ray exposure (I-F, 264.4 ± 97.4 mGy; RF, 224.9 ± 62.0 mGy; P = 0.039) and less duration of the procedure (I-F, 150.3 ± 27.5 min; RF, 174.2 ± 38.5 min; P = 0.003) compared to RF group. The freedom from atrial arrhythmia recurrence at 12 months post-ablation was similar between the RF and I-F groups (RF, 57.1%; I-F, 71.8%; P = 0.197). However, I-F group experienced lower rehospitalization rate of AF recurrence (RF, 42.9%; I-F, 20.5%; P = 0.038).
Conclusions: In NPAF patients requiring substrate mapping and modification, the "ICE-FIRE" ablation demonstrated non-inferior clinical efficacy and lower rehospitalization rate of AF recurrence when compared with pure radiofrequency ablation strategy.
Keywords: Circumferential pulmonary vein isolation; Non-paroxysmal atrial fibrillation; Substrate modification.