# Incidence and Predictors of Hypoattenuated Thickening and Device‐Related Thrombus at Three Months Postprocedural CT Assessment Following Left Atrial Appendage Occlusion With Amplatzer Devices—A Single‐Center Cohort

## TL;DR

This study examines the occurrence of hypoattenuated thickening and device-related thrombus after left atrial appendage occlusion, finding that clinical factors like female sex and prior stroke are more predictive than anatomical ones.

## Contribution

The study identifies clinical predictors of postprocedural complications after LAAO, emphasizing the protective role of dual antiplatelet therapy and the lack of value in anatomical predictors.

## Key findings

- Hypoattenuated thickening occurred in 24% of patients and device-related thrombus in 2.9% at 3 months post-LAAO.
- Female sex and prior stroke/TIA were significantly associated with hypoattenuated thickening.
- Dual antiplatelet therapy was linked to a lower incidence of hypoattenuated thickening and device-related thrombus.

## Abstract

Left atrial appendage occlusion (LAAO) has become a valuable alternative to long‐term anticoagulation for stroke prevention in patients with non‐valvular atrial fibrillation (AF), especially in those at high bleeding risk. Hypoattenuated thickening (HAT) and device‐related thrombus (DRT) remain notable postprocedural concerns. Identifying reliable predictors is essential to optimize post‐LAAO management.

The aim of this study was to assess the incidence of HAT and DRT at 3 months following percutaneous LAAO and to identify clinical, anatomical, and procedural predictors—based on CT imaging evaluation—that may guide optimization of postprocedural antithrombotic strategies.

We conducted a retrospective single‐center study including adult patients who underwent percutaneous LAAO with Amplatzer Amulet or ACP devices at Dijon University Hospital between April 2016 and May 2024, with available pre‐ and 3‐month postprocedural CT scans. Baseline clinical, echocardiographic, biological, procedural, and anatomical data were collected. The primary objective was to determine the incidence and predictors of HAT and DRT at 3 months.

Among 102 patients (mean age 76 ± 7 years, mean CHADS‐VASc 4.4 ± 1.4), HAT was observed in 25 (24%), and DRT in 3 (2.9%). Female sex and prior stroke/TIA were significantly associated with HAT occurrence. Importantly, patients discharged on dual antiplatelet therapy (DAPT) demonstrated a markedly lower incidence of HAT/DRT, suggesting a protective effect. In contrast, no anatomical parameter, including the Cressa classification, predicted thrombotic events. While Cressa morphology correlated with procedural complexity, it had no value for thrombotic risk stratification.

This study highlights the absence of anatomical predictors of HAT/DRT, emphasizing instead clinical determinants and the protective role of DAPT. These findings support tailoring antithrombotic therapy after LAAO according to individual clinical risk profiles, particularly in patients with prior stroke/TIA or women, who may benefit from reinforced preventive strategies. Larger multicenter studies are needed to refine postprocedural management algorithms and improve risk stratification beyond anatomical assessment.