Freedom from AF—comparison of Cryo vs. RF in the four centres performing the two techniques for a first procedure of paroxysmal AF ablation. Note: Centres A, C, E, and F have performed 51, 64, 189, and 349 RF ablations of AF per year, respectively, at the time of data collection. RF, radiofrequency ablation; Cryoballoon, Cryoballoon ablation; B, C, D, and F, centres; AF, atrial fibrillation.