Transcatheter occlusion of the left atrial appendage-experimental testing of a new amplatzer device

Objectives: This study assessed the feasibility and efficacy of implanting a new nitinol device in the left atrial appendage (LAA) in a canine model. Background: Left atrial thrombus occurs in the LAA in 90% of humans with nonvalvular atrial fibrillation (AF). Methods: The Amplatzer Left Atrial Appendage Occluder Device now known as the Amplatzer Cardiac Plug (Amplatzer Medical LLC, Plymouth MN) is a new transcatheter Nitinol device containing polyester fabric designed to seal the LAA. The device was implanted in 10 canines with immediate, ∼30 and ∼90-day follow-up by echocardiography, angiography, and final pathological examination. Results: The device was successfully implanted in all animals and found to be retrievable and repositionable. There was complete occlusion of the LAA in all cases without embolization. There was no thrombus formation on the device and no pericardial effusion or impingement on the circumflex coronary artery, mitral valve, or left pulmonary vein. A single instance of tiny left atrial mural thrombus at device end screw contact was attributed to the small canine left atrium. Conclusions: The success of this animal study confirms safety and feasibility of the Amplatzer Cardiac Plug. Human trials are warranted.