Atrial electroanatomical remodeling as a determinant of different outcomes between two current ablation strategies: circumferential pulmonary vein isolation vs pulmonary vein isolation.

Background: The purpose of this study was to investigate the relationship between the efficacy of the 2 different ablation techniques of atrial fibrillation (AF) and left atrial (LA) size.
Methods and Results: A total of 81 patients with paroxysmal AF (n = 58) or persistent AF (n = 23) refractory to antiarrhythmic drugs underwent circumferential pulmonary vein isolation (PVI; n = 45) or PVI (n = 36) without respect to echocardiographic results for LA volume index (LAVI). Of the 81 patients, 41 had less dilated LA (group 1; LAVI < 27 cc/m(2)) and 40 had dilated LA (group 2; LAVI > or = 27 cc/m(2)). During the 9-month follow-up, 33 patients (73.3%) after circumferential PVI and 18 (50%) after PVI (P = .031) were free of arrhythmia. The risk of recurrence was associated with persistent AF, hypertension, LAVI > 27 ml/m(2), PVI, early recurrence of AF, and lower left ventricular (LV) ejection fraction (all P value <.05). In the univariate analysis of each group, PVI (hazard ratio [HR]: 2.92, 95% confidence interval [CI]: 0.12-7.08, P = .018) was associated with late recurrence only in group 2. Cox regression analysis also showed that PVI (HR: 5.6, 95% CI: 1.9-16.56, P = .002) was a significant independent predictor of recurrence only in group 2.
Conclusions: Circumferential PVI is more effective than PVI only in patients with a structural change of the atria, that is, a dilated LA. Our study suggests that a successful outcome in dilated LA may depend on wide modification of LA electroanatomical substrates, but wide ablation in less dilated LA may be unnecessary. Different technical strategies according to LA size are required for more a effective outcome.
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