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Left Atrial Imaging Prior to Cardioversion: Leveraging Computed Tomography to Rule Out Thrombus (LACLOT)

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ClinicalTrials.gov Identifier: NCT04223505
Recruitment Status : Recruiting
First Posted : January 10, 2020
Last Update Posted : July 14, 2023
Sponsor:
Information provided by (Responsible Party):
Ottawa Heart Institute Research Corporation

Brief Summary:
Evaluating contrast enhanced ECG-gated cardiac CT (CCT) as an alternative to transesophageal echocardiography (TEE) to expedite cardioversion of atrial fibrillation (AF), improve patient care and reduce hospital admissions for AF and atrial flutter.

Condition or disease Intervention/treatment Phase
Atrial Fibrillation Diagnostic Test: Contrast enhanced ECG-gated cardiac CT (CCT) Diagnostic Test: Transesophageal Echocardiography (TEE) Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 100 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: Left Atrial Imaging Prior to Cardioversion: Leveraging Computed Tomography to Rule Out Thrombus
Actual Study Start Date : June 26, 2020
Estimated Primary Completion Date : June 1, 2024
Estimated Study Completion Date : August 30, 2025

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Active Comparator: TEE arm
TEE will be performed as per clinical routine using multiple standard tomographic planes to rule-out LA/LAA thrombus. Echocardiographic analysis will include: LAA-emptying velocity, and grading the severity of LAA spontaneous ECHO. The severity of the SEC will be graded on a 4 point scale with 1 = minor homogeneous contrast enhancement, 2 = significant homogeneous contrast enhancement, 3 = significant, dense, and inhomogeneous, slow-moving contrast, and 4 = dense slow-moving contrast.
Diagnostic Test: Transesophageal Echocardiography (TEE)
TEE is considered the reference standard to rule-out left atrial (LA) and left atrial appendage (LAA) thrombus prior to cardioversion. Several studies have examined the accuracy of TEE for detecting LAA thrombus. Compared to autopsy and intraoperative findings, TEE has a mean sensitivity of 100% and mean specificity of 99%. Although the gold standard, a TEE-guided therapy is still associated with an embolic rate of 0.8%.

Experimental: CCT arm
As per local protocol, a non-contrast enhanced prospective ECG-triggered image acquisition will be acquired. This will be followed by a contrast-enhanced prospective ECG-triggered will be acquired using a tri-phasic contrast protocols. Delayed CT images will be acquired 60 seconds after the initial contrast-enhanced CT scan.Cardiac CT image interpretation will be performed as per clinical routine. The LA and LAA will be assess for filling defects and characterized based upon attenuation values. If LA/LAA thrombus cannot be excluded, filling defects will be assessed on the delay images. Increases in attenuation would be consistent with pseudo-thrombus from 'slow flow' and 'incomplete opacification'. Areas where attenuation does not change significantly (persistent filling defect) will be diagnosed as thrombus. It will be recommended that patients with thrombus will undergo TEE.
Diagnostic Test: Contrast enhanced ECG-gated cardiac CT (CCT)
Contrast enhanced ECG-gated cardiac CT (CCT) is a sensitive, noninvasive alternative method used to exclude of left atrial and LAA thrombus. CCT provides high spatial and good temporal resolution and its ability to detect thrombus has been evaluated. CCT, compared to TEE, for the exclusion of thrombus in the LAA had a sensitivity and specificity of 100% and 99.3%, respectively. A high sensitivity is needed to minimize risk of embolus, and if a thrombus is detected on CT, a confirmatory TEE may be performed or patients may receive anticoagulation. Some argue that the potential benefits of CT and its lower associated procedural risk, the risk:benefit ratio would still favour CT.

Diagnostic Test: Transesophageal Echocardiography (TEE)
TEE is considered the reference standard to rule-out left atrial (LA) and left atrial appendage (LAA) thrombus prior to cardioversion. Several studies have examined the accuracy of TEE for detecting LAA thrombus. Compared to autopsy and intraoperative findings, TEE has a mean sensitivity of 100% and mean specificity of 99%. Although the gold standard, a TEE-guided therapy is still associated with an embolic rate of 0.8%.




Primary Outcome Measures :
  1. Time to cardioversion [ Time Frame: Up to 30 days ]

Secondary Outcome Measures :
  1. Hospital admission rate [ Time Frame: Up to 30 days ]

Other Outcome Measures:
  1. Length of hospital stay [ Time Frame: Up to 30 days ]
  2. Adverse events [ Time Frame: Up to 30 days ]


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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  1. Admitted patients who require LA imaging prior to cardioversion
  2. Age ≥18 years old
  3. Able and willing to comply with the study procedures

Exclusion Criteria:

  1. Indication for acute cardioversion (e.g. hemodynamic instability, acute coronary syndrome (ACS), or pulmonary edema)
  2. Unwillingness or inability to provide informed consent
  3. Contraindication to Cardiac CT

    • Severe renal insufficiency(GFR< 45ml/min)
    • Allergy to intravenous contrast agents
    • Contraindications to radiation exposure (for example, pregnancy)
    • Inability to perform 20-second breath-hold
  4. Contraindication to TEE

    • Unrepaired tracheoesophageal fistula
    • Esophageal obstruction or stricture
    • Perforated hollow viscus
    • Poor airway control
    • Severe respiratory depression
    • Uncooperative, unsedated patient

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04223505


Contacts
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Contact: Farrah Ahmed 613-696-7000 ext 12697 fahmed@ottawaheart.ca
Contact: Sandina Jamieson 613-696-7286 sjamieson@ottawaheart.ca

Locations
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Canada, Ontario
University of Ottawa Heart Institute Recruiting
Ottawa, Ontario, Canada, K1Y 4W7
Contact: Benjamin JW Chow, MD    613-696-7286    bchow@ottawaheart.ca   
Principal Investigator: Benjamin JW Chow, MD         
Sponsors and Collaborators
Ottawa Heart Institute Research Corporation
Investigators
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Principal Investigator: Benjamin Chow, MD UOHI
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Responsible Party: Ottawa Heart Institute Research Corporation
ClinicalTrials.gov Identifier: NCT04223505    
Other Study ID Numbers: 201900117-01H
First Posted: January 10, 2020    Key Record Dates
Last Update Posted: July 14, 2023
Last Verified: July 2023
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes