Feasibility and safety of combined left atrial appendage occlusion and catheter ablation in persistent atrial fibrillation with left atrial appendage thrombus: The COAT procedure.

BACKGROUND

Left atrial appendage thrombus (LAAT) in non-valvular atrial fibrillation (AF) usually precludes catheter ablation and complicates left atrial appendage occlusion. Patients with persistent LAAT despite anticoagulation and heart failure have limited rhythm-control options.

OBJECTIVE

To describe the feasibility and safety of combined occlusion and ablation therapy for LAAT (COAT), a same-session "thrombus-sealing first" strategy, in selected patients with persistent AF, heart failure, and persistent LAAT despite therapeutic oral anticoagulation.

METHODS

This single-center retrospective proof-of-concept cohort included 5 patients who underwent COAT between January 2022 and April 2026. Left atrial appendage occlusion was performed first using a no-touch thrombus-trapping technique. Catheter ablation was performed after device release, confirmation of device stability and sealing, and absence of neurological abnormality. Follow-up included imaging and rhythm surveillance with electrocardiography and Holter monitoring.

RESULTS

All 5 procedures were completed successfully, with first-attempt device deployment and pulmonary vein isolation in all patients. Sinus rhythm was restored in all patients. No periprocedural stroke, transient ischemic attack, systemic embolism, major bleeding, pericardial tamponade/effusion, device embolization, or death occurred. At a median imaging follow-up of 58 days, transesophageal echocardiography (TEE) confirmed complete LAA sealing without device-related thrombus in 4 patients; 1 patient declined TEE and cardiac computed tomography angiography. The 4 patients with TEE follow-up were transitioned from anticoagulation to lifelong single antiplatelet therapy. No thromboembolic or major bleeding events occurred. 4 patients remained arrhythmia-free.

CONCLUSION

In this small, selected proof-of-concept cohort, COAT appeared feasible and was not associated with observed major complications. Larger prospective studies are required.