search
Back to results

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

Primary Purpose

Atrial Fibrillation

Status
Recruiting
Phase
Not Applicable
Locations
Canada
Study Type
Interventional
Intervention
Contrast enhanced ECG-gated cardiac CT (CCT)
Transesophageal Echocardiography (TEE)
Sponsored by
Ottawa Heart Institute Research Corporation
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional diagnostic trial for Atrial Fibrillation

Eligibility Criteria

18 Years - undefined (Adult, Older Adult)All SexesDoes not accept healthy volunteers

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

Sites / Locations

  • University of Ottawa Heart InstituteRecruiting

Arms of the Study

Arm 1

Arm 2

Arm Type

Active Comparator

Experimental

Arm Label

TEE arm

CCT arm

Arm Description

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.

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.

Outcomes

Primary Outcome Measures

Time to cardioversion

Secondary Outcome Measures

Hospital admission rate

Full Information

First Posted
January 6, 2020
Last Updated
July 13, 2023
Sponsor
Ottawa Heart Institute Research Corporation
search

1. Study Identification

Unique Protocol Identification Number
NCT04223505
Brief Title
Left Atrial Imaging Prior to Cardioversion: Leveraging Computed Tomography to Rule Out Thrombus
Acronym
LACLOT
Official Title
Left Atrial Imaging Prior to Cardioversion: Leveraging Computed Tomography to Rule Out Thrombus
Study Type
Interventional

2. Study Status

Record Verification Date
July 2023
Overall Recruitment Status
Recruiting
Study Start Date
June 26, 2020 (Actual)
Primary Completion Date
June 1, 2024 (Anticipated)
Study Completion Date
August 30, 2025 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Ottawa Heart Institute Research Corporation

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
Yes

5. Study Description

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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Atrial Fibrillation

7. Study Design

Primary Purpose
Diagnostic
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
100 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
TEE arm
Arm Type
Active Comparator
Arm Description
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.
Arm Title
CCT arm
Arm Type
Experimental
Arm Description
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.
Intervention Type
Diagnostic Test
Intervention Name(s)
Contrast enhanced ECG-gated cardiac CT (CCT)
Intervention Description
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.
Intervention Type
Diagnostic Test
Intervention Name(s)
Transesophageal Echocardiography (TEE)
Intervention Description
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 Measure Information:
Title
Time to cardioversion
Time Frame
Up to 30 days
Secondary Outcome Measure Information:
Title
Hospital admission rate
Time Frame
Up to 30 days
Other Pre-specified Outcome Measures:
Title
Length of hospital stay
Time Frame
Up to 30 days
Title
Adverse events
Time Frame
Up to 30 days

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Admitted patients who require LA imaging prior to cardioversion Age ≥18 years old Able and willing to comply with the study procedures Exclusion Criteria: Indication for acute cardioversion (e.g. hemodynamic instability, acute coronary syndrome (ACS), or pulmonary edema) Unwillingness or inability to provide informed consent 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 Contraindication to TEE Unrepaired tracheoesophageal fistula Esophageal obstruction or stricture Perforated hollow viscus Poor airway control Severe respiratory depression Uncooperative, unsedated patient
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Farrah Ahmed
Phone
613-696-7000
Ext
12697
Email
fahmed@ottawaheart.ca
First Name & Middle Initial & Last Name or Official Title & Degree
Sandina Jamieson
Phone
613-696-7286
Email
sjamieson@ottawaheart.ca
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Benjamin Chow, MD
Organizational Affiliation
UOHI
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Ottawa Heart Institute
City
Ottawa
State/Province
Ontario
ZIP/Postal Code
K1Y 4W7
Country
Canada
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Benjamin JW Chow, MD
Phone
613-696-7286
Email
bchow@ottawaheart.ca
First Name & Middle Initial & Last Name & Degree
Benjamin JW Chow, MD

12. IPD Sharing Statement

Plan to Share IPD
No

Learn more about this trial

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

We'll reach out to this number within 24 hrs