Additional cavotricuspid isthmus block ablation may not improve the outcome of atrial fibrillation ablation

Aims Pulmonary vein isolation (PVI) is an effective procedure for atrial fibrillation (AF). The role of additional cavotricuspid isthmus (CTI) block ablation remains controversial in AF patients without atrial flutter (AFL). Therefore, this study aimed to explore the clinical outcome of additional CTI block ablation in patients without AFL. Methods Between January 2013 and December 2017, a total of 139 patients who did not have documented AFL and who underwent catheter ablation for AF were recruited. Fifty-seven patients were classified in additional CTI block ablation group and 82 patients were classified in without CTI group. The incidence of early-onset and late-onset atrial arrhythmia recurrence was compared between the two groups. Results The additional CTI group had a higher prevalence of persistent or long-standing AF and larger left atrial volume. The additional CTI group had a higher incidence of late-onset atrial arrhythmia recurrence (38.6% vs 12.2%; P < .001). When compared to without CTI group, additional CTI therapy did not have a better outcome in terms of freedom of atrial arrhythmia in subgroup analysis. The incidence of early-onset and late-onset atrial arrhythmia recurrence did not differ between additional CTI group and without CTI group in paroxysmal AF patients and nonparoxysmal AF patients after propensity scoring matching. Conclusion CTI block ablation in addition to PVI for AF patients without a history of AFL or inducible AFL during ablation may not improve the clinical outcome of AF ablation in the patients with larger LA volume, nonparoxysmal AF, or post-PVI inducible AF.