Electrical isolation of the left atrial appendage by Maze-like catheter substrate modification: A reproducible strategy for pulmonary vein isolation nonresponders?

INTRODUCTION: The ablation strategy for atrial fibrillation (AF) despite pulmonary vein isolation (PVI) is controversial. Left atrial appendage isolation (LAAI) may contribute to improve outcome. We describe an ablation approach ("Maze-like"-LAAI) that (1) modifies the underlying LA substrate by linear ablation (2) eliminates the LAA as a putative AF trigger site and (3) incorporates an unambiguous procedural endpoint. The role of LAA closure (LAAC) after LAAI was investigated.

METHODS: Patients with atrial tachyarrhythmias nonresponsive to PVI underwent a LAAI ablation procedure. LAAI was achieved by combining (a) an anterior line, (b) a LA roof line and (c) a mitral isthmus line. Patients continued oral anticoagulation (OAC) therapy or underwent LAAC  ≥6 weeks after LAAI.

RESULTS: Maze-like LAAI was attempted in our center in 107 of 3,611 AF ablation procedures (2.9%) and achieved in 88 of 107 patients (82%). In 8 of 107 (7%) patients cardiac tamponade occurred, all managed conservatively. During follow-up sinus rhythm was established in 65% at 1 year. After LAAI, 45 patients remained on OAC and 40 underwent LAAC. In both groups 1 patient experienced a bleeding complication. Thromboembolism exclusively occurred in the OAC group in 3 (7%) patients.

CONCLUSION: LAA isolation by Maze-like substrate modification may be considered a viable option for PVI non-responders. It offers a reproducible approach with an unambiguous procedural endpoint and leads to a favorable clinical outcome. However, extensive LA ablation increased the risk of tamponade. Consecutive LAA occlusion may offer a nonpharmacologic strategy to overcome the high thromboembolic risk associated with absent mechanical LAA contraction.