Left atrial volume at MRI is the main determinant of outcome after pulmonary vein isolation plus linear lesion ablation for paroxysmal-persistent atrial fibrillation.

Aims: To assess retrospectively clinical and procedural predictors of long-term recurrences after atrial fibrillation ablation.

Methods: Two hundred and forty consecutive patients (201 men; mean age 60 +/- 10 years) undergoing pulmonary vein isolation (PVI) plus linear lesion ablation for antiarrhythmic drug-refractory atrial fibrillation between 2005 and 2007 were studied. Magnetic resonance imaging of the left atrium was performed in all the patients. Patients were followed up with clinical examination and ECG Holter at 1, 3, 6 months and every 6 months thereafter. In case of recurrence, a second procedure was offered. Clinical and procedural data were evaluated with univariate and multivariate analysis.

Results: At a mean follow-up of 30.3 +/- 9.2 months after one or two procedures, 99 (41.3%) patients were in sinus rhythm without antiarrhythmic drugs and 50 patients (20.8%) had arrhythmia recurrences. These groups were compared in order to identify the clinical predictors of recurrences. Variables directly related to failure at univariate analysis were: history of persistent atrial fibrillation, number of previous electrical cardioversions, left atrial volume (LAV) at MRI, presence of pulmonary vein anatomical variants and BMI. At multivariate analysis, only left atrial volume measured at MRI was an independent predictor of failure.

Conclusion: With long-term follow-up, LAV at MRI represents the main determinant of outcome after PVI plus linear lesion for ablation of paroxysmal and persistent atrial fibrillation.