Conduction Recovery After Cavotricuspid Isthmus Ablation When Performed With or Without Concomitant Atrial Fibrillation Ablation.

ABSTRACT

OBJECTIVES: This study sought to define the association between conduction recovery across the cavotricuspid isthmus (CTI) and typical atrial flutter (AFL) recurrence when CTI ablation is performed with pulmonary vein isolation (PVI) compared with a stand-alone procedure. BACKGROUND: CTI ablation is commonly performed at the same time as PVI to treat AFL or as an empiric therapy. Conduction recovery is a recognized problem after linear ablation in the left atrium (e.g., mitral isthmus ablation) and is proarrhythmic. Less is known about conduction recovery after CTI ablation and possible differences in outcomes when performed at the time of PVI compared with at the time of a stand-alone procedure. METHODS: Eligible participants who underwent stand-alone CTI ablation were compared with those who underwent a combined (CTI+PVI) procedure. CTI conduction recovery was assessed at the time of a second ablation. Conduction recovery across the CTI (primary outcome) and recurrence of typical AFL (secondary outcome) were studied using multivariable logistic regression. RESULTS: Among 295 eligible participants (median age 64 years [interquartile range 55 to 69 years]; 33% women), recovery was assessed in 232 and was more common after combined versus stand-alone CTI ablation (52% [72 of 139] vs. 13% [12 of 93]; p < 0.001). In multivariable analysis, CTI ablation performed as a combined procedure increased odds of CTI conduction recovery 7.8-fold (odds ratio 7.8; 95% confidence interval 3.3 to 18.3; p < 0.001) and clinical AFL recurrence 4.1-fold (odds ratio 4.1; 95% confidence interval 1.0 to 16.9; p = 0.049). CONCLUSIONS: CTI ablation performed at the time of atrial fibrillation ablation is associated with higher rates of conduction recovery and typical flutter recurrence.