Introduction: Although having good initial results, during follow up recurrence rates after atrial fibrillation (AF) ablation are>30%. Ablation is recommended for patients with paroxysmalAF and nondilated left atrium (LA) but it is not uncommon to find patients with paroxysmalAF having dilated LA and with nonparoxysmalAF having nondilated LA. Our goal was to determine independent predictors of recurrence and to evaluate whether LA enlargement or persistentAF determines worse outcome.
Methods and Results: We evaluated 407 consecutive patients admitted for AF ablation from June-2005 to June-2010 pts, 23.6% female, 56±11 years. AF was paroxysmal in 69.3% (n=282), mean indexed LA volume 56±20ml/m2. FUp was made by in clinic evaluation (with ECG or 24hours Holter by protocol and driven by symptoms) and by phone interview whenever necessary. During a follow up of 21±11 months AF recurrence was 34% (139pts). Independent predictors of recurrence were female sex (OR-1.97;95%CI-1.21-3.23;p=0.007) and left atrial indexed volume over 61ml/m2 (OR-2.25;95%CI1.43-3.54;p<0.001). Type of AF at presentation was not predictor of recurrence. In patients with non dilated LA, 60 (22.4%) had non paroxysmal AF. In this subgroup, AF type at presentation had no statistic impact on recurrence (26.4%vs30.0%;p=0.62,paroxysmal vs non paroxysmal). If a patient presented with non paroxysmal AF, having a LA<61ml/m2 was associated with a significant better outcome 30% vs 56,1% (adjusted OR0.32,95CI-0.15-0.67).
Conclusions: In our series a recurrence rate of 34% was observed during a follow up of 21±11 months. Female sex, LA indexed volume and not type of AF at presentation were independent predictor of recurrence. A LA<61ml/m2 was associated with better outcome irrespectively of AF type and thus patients presenting with non paroxysmal AF might still benefit from ablation if a non dilated LA is present. Adequate patient selection is still a main determinant to ablation success and early stages of disease characterized by lower LA volumes seem to be related with lower recurrence rates.