Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Current guidelines recommend catheter ablation of AF in symptomatic patients refractory to antiarrhythmic therapy. Pulmonary vein isolation (PVI) remains the cornerstone of any ablation procedure irrespective of patient characteristics. Recently, single fraction stereotactic radioablation has been used in patients with ventricular arrhythmias non-eligible for transcatheter ablation or after a failed transcatheter ablation.~This is a single center, single arm, prospective and phase 1 clinical trial. Patients with refractory AF non-eligible for transcatheter ablation or after a failed transcatheter ablation will receive stereotactic radioablation for PVI.~The target contours for paroxysmal AF stereotactic radioablation will cover the left atrial-venous wall, the myocardium and the myocardial sleeves of the PVs transmural at the PV antrum, similar to catheter ablation. The contours will be approximately 4-6 mm wide along the PVs / LA and approximately 2-4 mm deep depending on the tissue thickness.~A pre-validation study will evaluate the location with respect to right and left PVs. Patients with esophagus in direct contact with the actual target lesion will be excluded.~PVI will be assessed by means of Cardio Insight non invasive mapping system during radioablation.~Safety is the primary endpoint of the study. Safety will be assessed by incidence and evaluation of any serious adverse evens using CTCAE V5.0 criteria associated with the procedure through 90 days (short-term) and 12 months (intermediate term).~Efficacy will be evaluated by assessing atrial fibrillation recurrence and AF burden after 90 days of blank period until 12 months post-treatment based on pacemaker interrogation.
The study aims to investigate the short-term (3 months) and intermediate-term (12 months) safety and preliminary efficacy of stereotactic radiotherapy for pulmonary vein isolation to treat refractory atrial fibrillation.