Intra-procedural imaging of the left atrial appendage: implications for closure with the Amplatzer™ cardiac plug

Objectives: To evaluate intra-procedural imaging with transesophageal echocardiography and angiography during left atrial appendage occlusion using the Amplatzer™ Cardiac Plug with regard to sizing and final device shape.

Methods: Left atrial appendage ostium dimensions and diameter at a depth of 10mm from the ostium were measured by transesophageal echocardiography (0-180°) and angiography (RAO 30° - Cranial 20°) in consecutive patients undergoing left atrial appendage occlusion using the ACP with an oversizing strategy of 10-20% relative to the baseline measurements. After delivery, ACP dimensions were measured and device shape was assessed.

Results: Twenty-seven consecutive patients underwent successful uncomplicated left atrial appendage closure with Amplatzer™ Cardiac Plug. We found a significant difference between the largest and smallest left atrial appendage diameter measured with transesophageal echocardiography (22.3±4.2 vs. 18.1±4.1mm, p<0.001). By the end of the procedure (by angiography), ACP had an optimal shape in 17 patients (63%), a strawberry-like shape in 7 patients (26%), and a square-like shape in 3 patients (11%). ACP was oversized on average by 1.5±2.7 and 3.3±2.3mm compared to transesophageal echocardiography and angiography, respectively. The final shape of the device was not significantly associated with the degree of oversizing.

Conclusions: We found a considerable variability in the assessment of the left atrial appendage, using transesophageal echocardiography and angiography. The degree of Amplatzer™ Cardiac Plug expansion within the left atrial appendage and the final shape of the device were not associated with the degree of oversizing.