Prospective randomized comparison between a fixed '2C3L' approach vs. stepwise approach for catheter ablation of persistent atrial fibrillation

Aims This prospective clinical trial was designed to evaluate the efficacy of an ablation strategy, namely '2C3L', in the treatment of persistent atrial fibrillation (AF); and to compare its efficacy with that of the 'stepwise' approach, which has been acknowledged as a promising ablation technique for persistent AF. Methods and results The '2C3L' technique is a fixed ablation approach consisting of bilateral circumferential pulmonary vein antrum isolation (PVAI) and three linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavo-tricuspid isthmus. One hundred and forty-six patients with persistent AF were randomized to undergo ablation by using the '2C3L' or the 'stepwise' technique (n = 73, respectively). The primary endpoint was freedom from any atrial tachyarrhythmia off antiarrhythmic drug (AAD) after a single procedure at follow-up. Twelve months after a single procedure, there was no difference in sinus rhythm (SR) maintenance rate between the two groups (67% for '2C3L' vs. 60% for 'stepwise', P = 0.394; 95% confidence interval of between-group difference -8.7 to 22.4%). The procedure (222 +/- 42 vs. 263 +/- 41 min), fluoroscopy (41 +/- 9 vs. 55 +/- 8 min), and radiofrequency (RF) (107 +/- 32 vs. 128 +/- 38 min) time were significantly shorter in the '2C3L' group (all P < 0.001). At 25 +/- 5 months after the first procedure, 57.5 and 52.1% of patients from the '2C3L' group and the 'stepwise' group were in SR off AAD (P = 0.494), respectively. Conclusions For catheter ablation of persistent AF, the '2C3L' strategy is a fixed approach associated with clinical efficacy similar to that of the 'stepwise' approach but with less RF delivery, fewer X-ray exposure, and shorter procedural time.