Left Atrial Appendage Electrical Isolation and Occlusion to Treat Persistent Atrial Fibrillation: A Safety and Feasibility Study (LEIO-AF)

While catheter ablation has revolutionized the treatment of atrial fibrillation (AF), the long-term outcomes in treating persistent AF are variable, often requiring more than one procedure to maintain long-term freedom from AF. Electrical isolation of the pulmonary veins (PVs) is central to catheter ablation strategies, with the majority of paroxysmal AF recurrences being associated with reconnection of previously isolated PVs. Persistent AF is different, with recurrences being attributable to foci and or substrate outside the PVs, including the left atrial appendage (LAA). Recently, a non-randomised, consecutive study of 987 patients undergoing repeat catheter ablation for persistent (82%) and paroxysmal (18%) AF has demonstrated that almost 30% of recurrences were due to an LAA focus and that the addition of LAA electrical isolation to a standard persistent AF ablation strategy improves freedom from AF.

Percutaneous LAA occlusion has been demonstrated to be as effective as warfarin in reducing the risk of thromboembolic stroke in patients with AF. The combination of a standard AF ablation lesion set with LAA electrical isolation and LAA occlusion may be an elegant method of improving success rates of ablation for persistent AF whilst also mitigating stroke risk and reducing the bleeding risks from long-term anticoagulation. However, the feasibility and safety of concomitant endocardial electrical isolation and mechanical occlusion of the LAA is not known.

In this study we test the hypothesis that concomitant electrical isolation of the LAA and its occlusion with a Watchman device, following a standard persistent AF lesion set is feasible and safe.