Linear ablation in addition to circumferential pulmonary vein isolation (Dallas lesion set) does not improve clinical outcome in patients with paroxysmal atrial fibrillation: a prospective randomized study

Aims Although the concept of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) was derived from maze surgery, it is unclear if linear ablation in addition to circumferential pulmonary vein isolation (CPVI) reduces the recurrence rate in patients with paroxysmal AF. Therefore, we compared clinical outcomes of CPVI with additional linear ablations (Dallas lesion set) and CPVI in a prospective randomized controlled study among patients with paroxysmal AF. Methods and results This study enrolled 100 paroxysmal AF patients (male 75.0%, 56.4 +/- 11.6 years old) who underwent RFCA and were randomly assigned to the CPVI group (n = 50) or the catheter Dallas lesion group (CPVI, posterior box lesion, and anterior Linear ablation, n = 50). The catheter Dallas Lesion group required longer procedure (190.3 +/- 46.3 vs. 161.1 +/- 30.3 min, P < 0.001) and ablation times (5345.4 +/- 1676.4 vs. 4027.2 +/- 878.0 s, P < 0.001) than the CPVI group. Complete bidirectional conduction block rate was 68.0% in the catheter Dallas lesion group and 100% in the CPVI group. Procedure-related complication rates were not significantly different between the catheter Dallas lesion (0%) and CPVI groups (4%, P -= 0.157). During the 16.3 + 4.0 months of follow-up, the clinical recurrence rates were not significantly different between the two groups (16.0% in the catheter Dallas lesion group vs. 12.0% in the CPVI group, P = 0.564), regardless of complete bidirectional conduction block achievement after linear ablation. Conclusion Linear ablation in addition to CPVI (catheter Dallas Lesion) did not improve clinical outcomes of RFCA in paroxysmal AF patients and required longer procedure times.