Mechanical occlusion of the left atrial appendage.

Introduction: Oral anticoagulation therapy reduces significantly the risk of thromboembolism in patients with atrial fibrillation. However, effective oral anticoagulation therapy is not feasible in all patients. The interventional occlusion of the left atrial appendage may reduce the risk of thromboembolism in the latter patients. The aim of this prospective study was to assess the feasibility, safety, and technical aspects of interventionally occluding the left atrial appendage. Methods and Results: The left atrial appendage was interventionally occluded with the new PLAATO device in nine patients. Serial transthoracic and transesophageal echocardiographic studies and neurologic assessment were performed prior to and during the procedure, and <48 hours, 3 months, 6 months, and 1 year after the procedure. Contraindications to oral anticoagulation were bleeding complications in 6 of 9 cases, cerebral aneurysm in 1, and allergies to warfarin therapy in 2 of 9. Baseline echocardiographic studies demonstrated spontaneous echo contrast grade 3 ± 1, peak emptying velocities of 0.26 ± 0.12 m/sec, and excluded atrial thrombi in all cases. Interventional occlusion was feasible in all cases. One patient had a minor plexus paresis that resolved within 4 weeks after the procedure. Neurologic assessment during a mean follow-up of 5 ± 4.4 months did not demonstrate any new neurologic complications. Serial echocardiographic assessment excluded the formation of thrombi on the implanted device and demonstrated its complete thrombosis after 6 months. One patient developed a minimal pericardial effusion 48 hours after the procedure that resolved within 3 months. Conclusion: Interventional occlusion of the left atrial appendage is feasible and safe in patients with atrial fibrillation and contraindications to oral anticoagulation therapy. Furthermore, no neurologic complications, development of atrial thrombi, or thrombus formation on the device were observed during follow-up. Future prospective studies are needed to clarify the long-term treatment effect of this new technique. (J Cardiovasc Electrophysiol, Vol. 14, pp. S56-S59, September 2003, Suppl.)