Prophylactic Cavotricuspid Isthmus Ablation in Patients without Typical Atrial Flutter: End of the Line

摘要

Atrial fibrillation (AF) is the most common arrhythmia and is frequently accompanied by atrial flutter (AFL) and sinus node dysfuction.1) The mechanisms of AF and AFL are closely related to each other. The onset of AFL is initiated by a transitional rhythm, usually AF. During long-term follow-up after cavotricuspid isthmus (CTI) ablation for AFL, incidental AF is common, suggesting that AFL is an early marker of atrial myopathy that progresses to AF.2) Interestingly, a recent meta-analysis reported the benefits of prophylactic pulmonary vein (PV) isolation during CTI ablation among patients without a previous history of AF.3) However, the role of prophylactic CTI ablation during PV antrum isolation (PVAI) in AF patients without a history of AFL is still unclear. This procedure is frequently performed in addition to PVAI, although evidence supporting the benefit of prophylactic CTI ablation in patients with AF has been limited. Three studies (one randomized controlled trial [RCT] and two retrospective studies) have evaluated prophylactic CTI ablation in AF patients without clinically documented AFL,4),5),6) with none showing additional benefit in reducing the recurrence of atrial tachyarrhythmia. A recent meta-analysis reported the role of prophylactic CTI ablation in AF patients with or without documented AFL.7) This study analyzed five studies: three RCTs and 2 retrospective observational studies matched with propensity scores.4),5),6),8),9) Both paroxysmal and non-paroxysmal type of AF were included. Additionally, 2 of the RCTs also included those patients with coexistent AF and AFL. The results showed that PVAI with CTI ablation in patients with AF did not reduce the risk of recurrence of atrial tachyarrhythmia compared to PVAI alone, regardless of the presence of AFL. Furthermore, additional CTI ablation tended to be associated with longer procedural time and higher complication rates. Interestingly, additional CTI ablation did not show better atrial tachyarrhythmia-free survival compared to PVAI alone, even in patients with documented AF and AFL, which supports the importance of the PV trigger in initiating AFL.