Impact of atrial remodeling on the outcome of radiofrequency catheter ablation of paroxysmal atrial fibrillation.

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/m(2)/PA-TDI duration <143ms), group 2 (LAVI ≥29ml/m(2)/PA-TDI duration <143ms), group 3 (LAVI <29ml/m(2)/PA-TDI duration ≥143ms), and group 4 (LAVI ≥29ml/m(2)/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.