Introduction: Pulmonary veins (PV) have been identified as triggers for Atrial Fibrillation (AF), and catheter radiofrequency ablation (RFA) is an effective treatment for AF. Recurrence of AF post-RFA can be predicted by clinical factors, including hypertension, left atrial enlargement and persistent AF. The importance of PV diameter in AF recurrence is less established.
Methods: We retrospectively analyzed 295 patients that underwent a first RFA between 2004 and July of 2011. A pre-procedure cardiac CT scan with PV diameter measurements was performed in all patients. Primary endpoint was documented ECG symptomatic recurrence of AF between 3 and 12 months post RFA. ROC curves and c-statistics were performed on all PV measurements and best cutoff value was determined. Multivariate analysis using logistic regression for predictors of AF recurrence was performed: Age > 65, AF Type (Paroxysmal vs. Persistent), Isolation of all 4 PVs, average of the largest diameter for all the PV and a single PV diameter equal or greater than 29 mm were considered.
Results: Mean age was 58±10 years and follow up 36±22 months. AF recurrence between 3 and 12 months post RFA was documented in 144 patients (49%). Multivariate Analysis identified Persistent AF (OR 2.6 95% CI 1.52 – 4.7 p=0.0006) and age > 65 (OR 1.8 95% CI 1.05-3.3 p=0.03) as the strongest predictors for AF recurrence. Interestingly, a PV diameter > 29 mm in any of the PV independently predicted AF recurrence (OR 13.1 95% CI 1.55-112.3 p=0.02). Isolation of all PVs was also a significant predictor of RFA success (OR 0.57 95% CI 0.34 -0.96 p= 0.03).
Conclusions: The strongest predictors were persistent AF and age with a 2-fold increase in risk of AF recurrence post RFA by 12 months. PV isolation of all PVs predicts RFA success. PV diameter > 29mm is an independent predictor of AF recurrence post RFA and should be further investigated.