FIRE or ICE for paroxysmal atrial fibrillation?—perspectives from the largest randomized evaluation of cryoballoon and radiofrequency ablation to date

Abstract

For patients with symptomatic paroxysmal atrial fibrillation (PAF), radiofrequency (RF) catheter ablation is now a common procedure worldwide and its cornerstone is the point-by-point electrical isolation of the pulmonary veins (PVI) (1). While short-term symptom improvement is frequently the case after a single ablation procedure (2), the sustained success of the procedure depends largely on the completeness of the isolation. Most patients with recurrent arrhythmia have evidence of electrical reconnection between the PVI and the atrial tissue (3). Performing complete and lasting PVI requires meticulous point-by-point delivery of RF ablation which can be tedious and is prone to incomplete lesion sets. To overcome this limitation and improve the efficiency of the procedure, a balloon-based catheter technology was developed with which a single circumferential isolation lesion can be delivered to the pulmonary vein antra via a catheter-guided cryotherapy balloon. This approach showed promising results and favorable learning curves in early feasibility studies (4,5) and in the Sustained Treatment of Paroxysmal Atrial Fibrillation (STOP AF) trial, the first randomized comparison of cryoballoon ablation versus antiarrhythmic drug therapy (6).In STOP AF, all four PVs were successfully isolated in 97.6% of patients and 12-month freedom from recurrent arrhythmia was ~70%. Results of randomized comparisons with the control group being treated with conventional RF ablation emerged shortly thereafter. In the Cryo vs. RF trial, 237 patients were randomized to first-generation cryoballoon ablation, RF ablation, or a combination of the two (7). The 1-year success rate (freedom from atrial arrhythmia after single procedure) was significantly higher in the cryoballoon group compared to the RF group (67% vs. 47%, P<0.001), while the combined approach was not significantly better than cryoballoon ablation alone. In the FreezeAF trial of 315 patients with PAF, cryoballoon ablation was noninferior to RF and 6-month procedural success was about 63% for both groups after a single procedure (8).Following these encouraging early results, cryoballoon ablation begun being utilized as an alternative to RF ablation, while more definitive data on the comparative performance of the two techniques was awaited. Establishing such definitive evidence was the goal of the FIRE AND ICE trial (9) which was designed to address the question: is cryoballoon ablation non-inferior to the conventional point-by-point RF ablation in terms of efficacy and safety? A total of 762 patients with drug-refractory, symptomatic PAF from 16 centers in eight European countries were enrolled and 750 patients were randomized 1:1 to the two techniques between 2012 and 2015. None of the included patients had undergone a prior ablation procedure. Patients were followed at regular clinic visits and arrhythmia surveillance was performed with 24-hr ambulatory ECG at Editorial

Left Atrial Volume Quantified by MSCT Predicts Emergency Hospitalizations for AF and Arrhythmia Recurrence after Catheter Ablation

“…[37][38][39] The present study demonstrated a low recurrence rate among patients following catheter ablation, in accordance with the largest study on this subject in the literature, which reported a recurrence rate of 34% after 1 year of followup. 40 The recurrence rate was significantly correlated with LAV, no recurrence being observed in cases with moderate enlargement. In cases with larger volumes, it increased to 53.84%, indicating that LA enlargement significantly influences the recurrence of AF following ablation therapy.…”