Background: Percutaneous bilateral pulmonary vein isolation is recommended for symptomatic drug refractory atrial fibrillation (AF). Different robotic devices are available for this procedure although the long term efficacy is not well established. The goal of this observational prospective study is to evaluate the efficacy of pulmonary vein isolation using magnetic navigation comparing to a non robotic conventional ablation.
Methods: We studied the 1140 consecutive patients admitted to first AF ablation (same medical team in two centers, one using only magnetic navigation and the other manual approach), 57 ± 11 years old, 71.5% male, 30.1% hypertensive, 70.5% Paroxysmal AF, left atrium volume 97.4±34.7ml. 3D mapping systems (CARTO for magnetic navigation and CARTO or NAV-X for manual approach) and circular Lasso catheter were used in all patients. Follow up included clinical evaluation (with ECG or 24h Holter recording by protocol and driven by symptoms) and phone interview. Success was classified in 3 classes: 1 - free of AF (no clinical or documented AF); 2 - clinical AF (AF symptoms not documented by ECG or 24h Holter recording lasting longer than 30sec); 3 - documented AF (ECG and 24h Holter recording lasting more than 30 sec).
Results: Ablation was performed with magnetic navigation in 540pts (47.4%). There were no differences regarding type of AF at presentation (76.5% robotic vs 67.6% conventional, p=NS) but patients in the magnetic navigation group had higher prevalence of hypertension (36.9% vs 16.9%; p<0.001). Magnetic navigation procedure lasted longer (189.3 ± 41.3 min vs 153.5 ± 58.4min, p<0.001) but needing lower fluoroscopy time (15 ± 12 min vs 28 ± 17 min; p<0.001). During an average follow up of 32.2±21.6 months, documented recurrence rates were lower in the magnetic navigation group (18.6% vs 32.1%, p=0.003). There was no difference regarding antiarrhythmic drug treatment (57.8% vs 55.3%, NS). In multivariate analysis, matching for follow up and clinical variables, Left atrial volume (OR 1.01; 95%CI 1.001-1.016;p=0.038) was the strongest predictor of recurrence and magnetic navigation was related to a lower recurrence rate (OR 0.55; 95%CI 0.31 – 0.98;p=0.04).
Conclusions: In our registry of patients submitted to pulmonary vein isolation, magnetic navigation with Stereotaxis® used lower fluoroscopy times and was non inferior during long term follow up when compared to manual approach.