Imaging risk features for device related pulmonary artery injury after left atrial appendage closure with Amplatzer™ Amulet™ device

Objectives: This study aimed to find imaging risk features for device related-pulmonary artery (PA) injury (DR-PAI) in patients after left atrial appendage closure (LAAC). Background: Cardiac tamponade resulting from DR-PAI is a rare but life-threatening complication of LAAC. Methods: In vitro analysis of Amplatzer™ Amulet™ (Abbott, MN) device was done. Measurements of the distance between PA and Amplatzer lobe at its middle part, distal part, and along the stabilizing wires' trajectory (wires-to-PA distance) were taken in 100 consecutive patients on post-LAAC computed tomography (CT) studies. Clinical outcomes were collected. Results: In vitro analysis indicated that both middle and distal lobe had to be in close PA proximity (<1.5 mm) for the stabilizing wires to cause risk for DR-PAI, configuration called ''cuddling lobe orientation''. On CT measurements middle lobe-PA distance was 4.7 mm (IQR = 2.7–9.5), with close proximity in 4 (4%) patients, and distal lobe-PA distance was 3.2 mm (IQR = 1.8–7.2 mm), with close proximity in 17 (17%) patients. Stabilizing wires were pointing toward PA in 47 patients (47%) with median wire-to-PA distance 5.7 mm (IQR = 3.6–8.5 mm). ''Cuddling'' was found in 2 (2%) patients and resulted in shorter wires-to-PA distance vs no ''cuddling'' group (2.3 vs 5.8 mm p <.01). At 2.9 ± 1.0 yrs of follow-up, the two patients with ''cuddling lobe orientation'' on post-LAAC CT scan developed late cardiac tamponades (p <.001). One of those required surgery, which confirmed DR-PAI. Conclusions: ''Cuddling lobe orientation'' of Amulet device with the PA was associated with short wires-to-PA distance and late pericardial effusions, including DR-PAI. Hence, such device-to-PA configuration should be avoided.