Device-Related Thrombus After Left Atrial Appendage Occlusion

Clinical relevance of incomplete device endothelialization after left atrial appendage closure

PURPOSE

This study aimed to assess the incidence, potential risk factors and clinical impact of incomplete device endothelialization(IDE) after left atrial appendage closure (LAAC).

METHODS

A total of 101 consecutive patients with nonvalvular atrial fibrillation (AF) who underwent successful LAAC and received antithrombotic treatment using a standard regimen were prospectively followed up to 6 months after the procedure. The status of device endothelialization and device-related thrombus (DRT) were evaluated using cardiac computed tomography (CT). Major adverse cardio-cerebral events (MACCE) including all-cause death, heart failure(HF) hospitalization, acute ischemic stroke, transient ischemic attack(TIA), peripheral vascular embolism, and major bleeding were recorded.

RESULTS

IDE was detected in 65 (64.4%) patients. Patients with IDE or complete device endothelialization (CDE) did not significantly differ with respect to baseline clinical characteristics and interventional procedure features. Multivariate analysis model revealed that persistent AF, left atrial appendage ostial diameter and left atrial size were independent risk factors for IDE. During 6-month follow-up, the incidence of DRT was 4.6% in patients with IDE and 2.8% in those with CDE, respectively (p > 0.05), and the overall rate of MACCE was non-significantly higher in the IDE group (7.7% vs. 2.8%, p = 0.32).

CONCLUSION

IDE is common after LAAC, especially in patients with persistent AF, higher left atrial appendage ostial diameter and left atrial size. IDE confers an increased risk for DRT, but may be not necessarily associated with thromboembolic events and poor clinical outcome, providing careful monitoring and continued antithrombotic therapy are given.

Diagnostic value of real-time four-dimensional transesophageal echocardiography on the implant-related thrombus

Objectives

This study aims to evaluate the diagnostic value of real-time four-dimensional transesophageal echocardiography (RT4D-TEE) for implant-related thrombus (IRT).

Methods

We collected 1,125 patients with atrial fibrillation from May 2019 to February 2022 in our hospital. All patients accepted transesophageal echocardiography (TEE) examination to exclude any thrombi before the LAAC procedure.

Results

There were 760 patients with LAAC, 66 patients with CIED, and 299 patients without any implantations. A total of 40 patients with an established diagnosis of IRT were further analyzed. The accurate detection rate of IRT by RT4D-TEE was 4.8% (40/826), which was higher than 3.8% (31/826) by 2D-TEE (P = 0.004). No IRT was found on TEE in the rest of the 786 patients. These 40 patients were divided into LAAC (n = 23) and CIED (n = 17) groups according to the results of RT4D-TEE. In the LAAC group, IRT distributed on different parts of the LAA occluder surface, 91.3% (21/23) with clumps of thrombi, and 8.7% (2/23) with a thin layer of thrombi covering the surface of the occluder. In the CIED group, thrombi were seen attached to the leads in the right atrium and right ventricle. The thrombi were beaded in 17.6% (3/17), corded in 17.6% (3/17), and clotted in the remaining 64.7% (11/17) of cases. After adjusting the anticoagulant dosage and following up for 6 months, 20% (8/40) of cases were successfully resolved, 67.5% (27/40) became smaller, and 12.5% (5/40) showed no changes.

Conclusion

The accurate detection rate of IRT by RT4D-TEE was significantly higher than that by 2D-TEE. 2D-TEE has limitations, but RT4D-TEE can be used as an effective complementary method. Imaging and some clinical features differ significantly between IRT on occluder and IRT on CIED lead.