Impact of Atrial Remodeling on the Outcome of Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation

Abstract

Background: Both the left atrial volume index (LAVI) and estimated total atrial conduction time measured using tissue Doppler imaging of the atria (PA-TDI duration) are echocardiographic parameters reflecting atrial remodeling. We investigated their prognostic value for atrial tachyarrhythmia (AF/AT) recurrence after radiofrequency catheter ablation (RFCA) of paroxysmal atrial fibrillation (PAF). Methods and Results: We analyzed the data for 100 consecutive patients with drug-refractory PAF who underwent RFCA. The correlation between the LAVI and PA-TDI was extremely weak (r=0.26, P<0.01). We categorized the patients into 4 groups based on the median LAVI and PA-TDI duration: group 1 (LAVI <29ml/m²/PA-TDI duration <143ms), group 2 (LAVI ≥29ml/m²/PA-TDI duration <143ms), group 3 (LAVI <29ml/m²/PA-TDI duration ≥143ms), and group 4 (LAVI ≥29ml/m²/PA-TDI duration ≥143ms). With a mean follow-up of 20.2±8.9 months after a single RFCA procedure, 60 patients (60%) were in sinus rhythm without any antiarrhythmic drugs. Multivariate analysis using a Cox proportional hazards model demonstrated that the group was an independent predictor of AF/AT recurrence after RFCA (P=0.0017). The patients in groups 2, 3, and 4 had a 4.0-fold (P=0.048), 6.8-fold (P=0.0034) and 10.9-fold (P=0.0001) increase, respectively, in the probability of recurrent AF/AT as compared with group 1. Conclusions: Preprocedural echocardiographic estimation of atrial remodeling was a useful predictor of AF/AT recurrence following a single RFCA of PAF.  (Circ J 2014; 78: 872–877)