Results from a multicentre comparison of cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: is cryoablation more reproducible?

Abstract

Aim: Cryoballoon ablation (Cryoballoon) has emerged as a new alternative for the treatment of symptomatic drug-refractory atrial fibrillation (AF). Whether the results of Cryoballoon are more reproducible than those of radiofrequency (RF) ablation remains to be proved.

Methods and results: A total of 860 consecutive patients undergoing a first ablation procedure for paroxysmal AF (467 treated with RF and 393 treated with Cryoballoon) were selected from a prospective multicentre survey of AF ablation (FrenchAF). Radiofrequency and Cryoballoon were compared regarding mid-term efficacy and safety. During a median follow-up of 14 months (interquartile range 8-23), patients treated with Cryoballoon displayed similar rates of freedom from atrial arrhythmia relapse in centres performing this technique (68-80% at 18 months). However, in centres performing RF, a greater heterogeneity in procedural results was observed (46-79% were free from atrial arrhythmia relapse at 18 months). On multivariate analysis, Cryoballoon (HR = 0.47, 95% CI 0.35-0.65, P < 0.001) and annual AF ablation caseload (HR = 0.87 per every 100 AF ablation procedures per year; 95% CI 0.80-0.96, P = 0.003) were independent predictors of procedural success. However, on sensitivity analysis, according to the ablation method, annual AF ablation caseload predicted only sinus rhythm maintenance in the subgroup of patients treated with RF. Analysis of interoperator results with Cryoballoon and RF confirmed lower reproducibility of RF, but suggested that besides caseload, other operator-related factors may play a role.

Conclusion: Cryoballoon seems to be less operator-dependent and more reproducible than RF in the setting of paroxysmal AF ablation.

Keywords: Arrhythmia; Atrial fibrillation; Catheter ablation; Cryoballoon; Efficacy; Radiofrequency ablation; Safety.