PVI Alone Versus PVI Plus PWI and SVCI With PFA

Catheter based ablation of atrial fibrillation (AF) is an established treatment modality for rhythm control of AF, with pulmonary vein isolation (PVI) being the cornerstone of this technique. While pulmonary vein triggers are the predominant arrhythmia mechanism in paroxysmal AF, development of additional atrial substrate contributes to maintenance of AF in persistent AF. This is likely to account for the lower rates of freedom from recurrent AF following ablation in patients with persistent AF. Various adjunctive empiric ablation strategies, such as left atrial posterior wall isolation (PWI), superior vena cava isolation (SVCI), linear ablation, and ablation of complex fractionated atrial electrograms have been studied to address this limitation of PVI alone.

While observational data supports the safety and feasibility of Posterior Wall Isolation (PWI) and Superior Vena Cava Isolation (SVCI) with PFA, the efficacy of these strategies with PFA has not been demonstrated in randomized controlled trials. Whether mapping prior to ablation (i.e. detecting scar) predicts if PW and SVC sites are effective in improving ablation outcome is unknown.

This study will test the hypothesis of whether empiric addition of PW and SVC isolation with PFA to PVI improves outcome (freedom from atrial tachyarrhythmia at 1-year). The investigators therefore propose a randomized controlled trial to compare the efficacy of Pulmonary Vein Isolation (PVI) alone versus PVI + PWI + SVCI in patients with persistent AF. The investigators hypothesize that the addition of PWI and SVCI to PVI in patients with persistent AF will provide improved freedom from AFIB off anti-arrhythmic drugs, without significantly increasing rates of procedural complications. Secondary analysis includes subgroups with posterior wall scar, procedure times, freedom from AFIB on or off anti arrhythmic drugs, etc.