Research on Post-Stroke Anticoagulation Strategies for Atrial Fibrillation Based on Left Atrial Appendage Flow Velocity Measured by Intracardiac Echocardiography (ICE)

NCT07439731 — Completed, 172 participants, Changhai Hospital

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Registry	NCT07439731
Status	Completed
Study type	Observational
Enrollment	172 (Actual)
Sponsor	Changhai Hospital (Other); collaborators: Shanghai Shidong Hospital, Yangpu District, Eastern Hepatobiliary Surgery Hospital
Conditions	Atrial Fibrillation (AF)
Interventions	Intracardiac Echocardiography (ICE) for Differential Diagnosis (Diagnostic test)
Dates	start 2024-01-01, primary completion 2024-12-31, completion 2024-12-31, first posted 2026-02-27, last updated 2026-02-27
Locations	2 sites in China

-Summary

1. Study Purpose The primary aim of this research was to systematically describe and characterize a novel, thrombus-mimicking artifact observed during Intracardiac Echocardiography (ICE), termed the "Floating Lotus" sign. The study sought to define its imaging features, determine its prevalence, and identify the clinical factors that predict its occurrence. This was driven by the clinical need to prevent the misdiagnosis of this pseudo-thrombus as a true Left Atrial Appendage (LAA) thrombus, which could lead to unnecessary procedure cancellations or anticoagulation changes.
2. Study Population The study population consisted of 172 consecutive patients with non-valvular atrial fibrillation (AF) who underwent ICE-guided catheter ablation and/or left atrial appendage occlusion (LAAO) between January and December 2024 across three tertiary medical centers. Patients with confirmed intracardiac thrombus, significant valvular heart disease, or prior cardiac surgery were excluded.
3. Key Research Focus

The key research focus was a multi-faceted investigation of the "Floating Lotus" sign:

Incidence and Imaging Characterization: To quantify how common this sign is (found in 27.9% of patients) and meticulously describe its dynamic sonographic appearance-a mobile, echogenic mass within an anechoic space (pericardial effusion) that merges with the LAA wall upon catheter rotation.

Identification of Clinical Predictors: To analyze which patient factors are associated with the sign. The study identified heart failure (LVEF <55%) as the sole independent predictor through multivariable analysis.

Clinical Correlation and Differentiation: To examine the sign's association with other clinical parameters (e.g., recent stroke, larger left atrial diameter) and emphasize the critical imaging maneuver (catheter rotation) that differentiates it from a true LAA thrombus, thereby highlighting its direct implications for procedural safety and decision-making.

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+Arms and interventions

Intracardiac Echocardiography (ICE) for Differential Diagnosis (Diagnostic test), also known as Catheter Rotation Maneuver for Pseudo-Thrombus Differentiation: The core of this procedure is to perform a characteristic catheter operation on the basis of routine ICE scanning of the left atrial appendage: when an unclear, movable, chaotic echogenic mass (suspected thrombus) is observed in the standard plane, the operator needs to slowly and continuously rotate the ICE catheter clockwise. This dynamic maneuver aims to induce morphological changes in the echogenic mass, observe whether it merges with the left atrial appendage wall and reveals the underlying pectinate muscle structure, thereby confirming it as a pericardial effusion-related floating artifact (i.e., the 'Floating Lotus' sign), rather than a true intracavitary thrombus.

+Outcome measures

Primary outcomes

Incidence of the "Floating Lotus" Sign [Intraoperative]

Secondary outcomes

Independent Predictors of the "Floating Lotus" Sign [Preoperative baseline]
Determinants of Left Atrial Appendage (LAA) Emptying Velocity [Intraoperative]

+Eligibility

Sex: All

Inclusion Criteria:

* Patients with a confirmed diagnosis of non-valvular atrial fibrillation (paroxysmal or persistent).
* Completion of complete intracardiac echocardiography (ICE) imaging during the catheter ablation or left atrial appendage occlusion (LAAO) procedure.

Exclusion Criteria:

* Confirmed intracardiac thrombus on pre-procedural transesophageal echocardiography (TEE) or left atrial computed tomography angiography (CTA).
* Significant valvular heart disease (moderate or severe stenosis/regurgitation) or a history of cardiac surgery.
* Incomplete clinical or imaging data.

+Locations (2)

Facility	City	Country	Status
The First Affiliated Hospital of Naval Medical University (Shanghai Changhai Hospital)	Shanghai, Shanghai Municipality	China
Shanghai Shidong Hospital, Yangpu District	Shanghai, Shanghai Municipality	China