P1002Echocardiographic assessment of optimal device position after percutaneous left atrial appendage occlusion - introduction of a novel classification and its impact on outcome
Authors: Vij V O , Al-Kassou B , Nelles D , Stuhr M , Schueler R , Omran H , Schrickel J , Hammerstingl C , Nickenig G , Sedaghat A 
Published: October 2019

Abstract

Background
Left atrial appendage occlusion (LAAo) is an established therapy in patients with atrial fibrillation. However, criteria regarding optimal device position are not well defined making comparability of procedural results virtually impossible. We therefore sought to a) introduce a classification describing optimal vs. suboptimal device-position by assessing predefined parameters in transoesophageal echocardiography (TEE) and to b) analyze the impact of device-position on outcome in patients treated with different LAAo devices.

Methods and results
We retrospectively analyzed 120 patients who were treated by LAAo and had undergone follow-up TEEs after 3 or 6 months. Patients were at mean age: 76±8 years; female 40% and presented an increased CHADS-VASC- (4.6±1.4) and HAS-BLED-score (3.7±1). TEE-guidance was performed in all cases.
In 62.5% (75/120) pacifier occluders (PO) (ACP/Amulet, Lambre, Ultraseal) were used, whereas 37.5% (45/120) were treated with non-pacifier occluders (NPO) (Watchman, Wavecrest, Occlutech). To assess device position, TEE images in a commissural view (60–90°) were analyzed and characterised by 1) implantation depth in the left atrial appendage, 2) peridevice flow (PF) and 3) the angle between occluder disc and pulmonal ridge (LUPV). For the purpose of this study, optimal device position was defined as a) ostial (LUPV length <10mm) or slightly subostial position (LUPV length ≤15mm, angle ≥100°) with b) the absence of major PF (>3mm).
Overall, occluders were implanted at a depth of 12±7.8 mm with ostial positioning being achieved in 47.5% (57/120). Major PF was seen in 7.5% (9/120). NPOs were implanted deeper than POs (depth: 15.6±7.1 vs. 9.8±7.4 mm, p<0.01; ostial position: 31.1% vs. 57.3%, p<0.01) and were associated with a higher incidence of major PF (15.6% vs. 2.7%, p=0.01). Also, the depth/angle ratio was higher (i.e. “worse”) in NPOs (18.3±9 vs. 14.6±8, p<0.04). As a result, optimal device position was achieved in 48.3% (58/120) of all patients, with lower rates in NPOs than in POs (26.7% vs. 61.3%, p<0.01). Procedural aspects revealed slight differences in occluder size (optimal: 23.7±3.2 vs. suboptimal: 24.5±3.7 mm, p=0.3), need for repositioning (10.3% vs. 17.7%, p=0.25) and procedural duration (48±36 vs. 52±34 min, p=0.3).
Of interest, device related thrombi (DRT) occurred less frequently in optimally implanted devices (3.4% vs. 12.9%, p=0.06). Hereby, implantation depth and depth/angle ratio were found to be predictors for DRT in ROC-analysis, respectively (AUC: 0.7, 95% Confidence interval [CI]: 0.56–0.84, p=0.05 and AUC: 0.72, 95% CI: 0.58–0.86, p=0.03).
Optimal vs. suboptimal position

Conclusion
Echocardiographic classification of device-position is warranted to provide comparability and appears to be feasible. Based on the novel classification provided, optimal device-position is achieved in 50% and is found more often with the use of POs. DRT appeared to occur more often in suboptimal device-position.