Exclusion of Left Atrial Appendage Thrombus in Emergency Department Patients With Atrial Fibrillation Undergoing CT to Assess for Pulmonary Embolus: A Feasibility Study

NCT07647939 | Not Yet Recruiting FDA Device

• 1 other identifier: 24-0413-North Shore University
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate whether a quick, additional CT scan of the heart, performed immediately after a standard CT scan for pulmonary embolism, can effectively detect blood clots in the left atrial appendage (LAA) in patients with atrial fibrillation. Detecting these clots is crucial before certain heart procedures to prevent stroke. Currently, a different, more involved procedure (Transesophageal Echocardiography - TEE) is often used. This study will assess if this additional CT scan is feasible, meaning if it can provide clear enough images to identify LAA clots without needing more contrast dye. The study will involve 60 patients, half receiving an "ungated" CT scan and the other half a "gated" CT scan (timed with their heart rhythm). The results of these scans will not be used for immediate patient care during the study, but rather to evaluate the CT scan technique itself. There is no direct benefit to participants, but the information gained could lead to faster diagnosis and reduced unnecessary testing for future patients.

Conditions

Atrial Fibrillation (AF); Pulmonary Embolism (PE); Left Atrial Appendage Thrombosis

Outcome Measures

Primary Outcomes (1)

• Percentage of Indeterminate Left Atrial Appendage (LAA) Thrombus Scans

  The primary endpoint of this study is to test the hypothesis that less than or equal to 20% of the repeat CT scan (described above) will be indeterminate for the presence or absence of left atrial appendage thrombus. Additionally, the proportion of indeterminate gated CT scans will be compared to the proportion of indeterminate ungated CT scans.

  The overall assessment and statistical analysis of this primary outcome for feasibility determination will be conducted at the study completion, an average of one year.

Secondary Outcomes (1)

• Diagnostic Accuracy of Repeat CT Scan for Left Atrial Appendage (LAA) Thrombus Detection.

  The secondary outcome will only be calculated at the end of the study (expected date of one year from the first enrollment) if statistically appropriate.

Study Arms (2)

Delayed Un-gated CT Scan Arm

EXPERIMENTAL

This arm will include the first 30 patients, who will undergo a 60-second delayed, un-gated CT scan to assess the left atrial appendage.

Device: Delayed Un-gated CT Scan for Left Atrial Appendage Thrombus

Delayed Gated CT Scan Arm

EXPERIMENTAL

This arm will include the subsequent 30 patients, who will undergo a 60-second delayed, gated CT scan to assess the left atrial appendage.

Device: Delayed Gated CT Scan for Left Atrial Appendage Thrombus

Interventions

Delayed Gated CT Scan for Left Atrial Appendage Thrombus DEVICE

Patients already undergoing CT angiography for suspected pulmonary embolism will receive an additional, delayed gated CT scan (60 seconds after initial contrast injection) to assess for LAA clot. No additional intravenous contrast will be given.

Delayed Gated CT Scan Arm

Delayed Un-gated CT Scan for Left Atrial Appendage Thrombus DEVICE

Patients already undergoing CT angiography for suspected pulmonary embolism will receive an additional, delayed un-gated CT scan (60 seconds after initial contrast injection) to assess for LAA clot. No additional intravenous contrast will be given.

Delayed Un-gated CT Scan Arm

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients above 18 years of age years deemed candidates for CT angiography for pulmonary embolism by the primary team on clinical grounds and noted to be in atrial fibrillation at the time.
• Room air oxygen saturation above 92%
• Systolic blood pressure above 100 mm Hg
• Respiratory rate less than 24 breaths/min

You may not qualify if:

• Inability to personally give informed consent
• Pregnant or breastfeeding individuals
• Stroke like symptoms
• ECG criteria for ischemia or infarction
• Heart rate \<40 or \> 120 bpm (inclusive) or 3rd degree heart block
• Unable to lie flat for at least 10 minutes
• Unable to follow simple commands
• Northwell Health Employees.
• Non-English-speaking patients

Sponsors & Collaborators

• Northwell Health: lead
• Canon Medical Systems, USA: collaborator

Study Sites (1)

North Shore University Hospital

Manhasset, New York, 11030, United States

Location

Related Publications (5)

• Senadeera SC, Palmer DG, Keenan R, Beharry J, Yuh Lim J, Hurrell MA, Mouthaan P, Fink JN, Wilson D, Lim A, Wu TY. Left Atrial Appendage Thrombus Detected During Hyperacute Stroke Imaging Is Associated With Atrial Fibrillation. Stroke. 2020 Dec;51(12):3760-3764. doi: 10.1161/STROKEAHA.120.030258. Epub 2020 Nov 9.

  PMID: 33161849 BACKGROUND

• Pathan F, Hecht H, Narula J, Marwick TH. Roles of Transesophageal Echocardiography and Cardiac Computed Tomography for Evaluation of Left Atrial Thrombus and Associated Pathology: A Review and Critical Analysis. JACC Cardiovasc Imaging. 2018 Apr;11(4):616-627. doi: 10.1016/j.jcmg.2017.12.019.

  PMID: 29622180 BACKGROUND

• Ng AC, Adikari D, Yuan D, Lau JK, Yong AS, Chow V, Kritharides L. The Prevalence and Incidence of Atrial Fibrillation in Patients with Acute Pulmonary Embolism. PLoS One. 2016 Mar 1;11(3):e0150448. doi: 10.1371/journal.pone.0150448. eCollection 2016.

  PMID: 26930405 BACKGROUND

• Shinkins B, Thompson M, Mallett S, Perera R. Diagnostic accuracy studies: how to report and analyse inconclusive test results. BMJ. 2013 May 16;346:f2778. doi: 10.1136/bmj.f2778. No abstract available.

  PMID: 23682043 BACKGROUND

• Wang RC, Miglioretti DL, Marlow EC, Kwan ML, Theis MK, Bowles EJA, Greenlee RT, Rahm AK, Stout NK, Weinmann S, Smith-Bindman R. Trends in Imaging for Suspected Pulmonary Embolism Across US Health Care Systems, 2004 to 2016. JAMA Netw Open. 2020 Nov 2;3(11):e2026930. doi: 10.1001/jamanetworkopen.2020.26930.

  PMID: 33216141 BACKGROUND

MeSH Terms

Conditions

Atrial Fibrillation; Pulmonary Embolism

Condition Hierarchy (Ancestors)

Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Lung Diseases; Respiratory Tract Diseases; Embolism; Embolism and Thrombosis; Vascular Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: CARE PROVIDER
• Purpose: DIAGNOSTIC
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This is a non-randomized, sequential group assignment.

Study Record Dates

• First Submitted: March 16, 2026
• First Posted: June 15, 2026
• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: June 15, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)