Imaging Risk Features For Device Related Pulmonary Artery Injury After Left Atrial Appendage Closure With Amplatzer (Tm) Amulet (Tm) 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 (TM) Amulet (TM) (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.