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

NCT04223505 | Completed Results DMC

• 1 other identifier: 201900117-01H
• Study Type: interventional
• Target: 102
• Locations: 1 country
• Sites: 1

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.

Conditions

Atrial Fibrillation

Outcome Measures

Primary Outcomes (1)

• Time to Imaging

  This outcome was measured by calculating the time between admission and imaging.

  From admission to imaging/spontaneous cardioversion, up to approximately 30 days.

Secondary Outcomes (1)

• Time to Cardioversion

  From admission to cardioversion, up to approximately 30 days

Other Outcomes (2)

• Time to Hospital Discharge

  From admission to hospital discharge, up to approximately 90 days.

• QoL

  At hospital discharge

Study Arms (2)

TEE arm

ACTIVE COMPARATOR

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)

CCT arm

EXPERIMENTAL

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); Diagnostic Test: Transesophageal Echocardiography (TEE)

Interventions

Contrast enhanced ECG-gated cardiac CT (CCT) DIAGNOSTIC_TEST

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.

CCT arm

Transesophageal Echocardiography (TEE) DIAGNOSTIC_TEST

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%.

CCT arm; TEE arm

Eligibility Criteria

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

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• Ottawa Heart Institute Research Corporation: lead

Study Sites (1)

University of Ottawa Heart Institute

Ottawa, Ontario, K1Y 4W7, Canada

Location

MeSH Terms

Conditions

Atrial Fibrillation

Interventions

Echocardiography, Transesophageal

Condition Hierarchy (Ancestors)

Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Echocardiography; Cardiac Imaging Techniques; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Ultrasonography; Heart Function Tests; Diagnostic Techniques, Cardiovascular

Results Point of Contact

• Title: Dr. Benjamin Chow
• Organization: University of Ottawa Heart Institute

bchow@ottawaheart.ca

6136966786

Study Officials

• Benjamin Chow, MD

  UOHI

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 6, 2020
• First Posted: January 10, 2020
• Study Start: June 26, 2020
• Primary Completion: November 21, 2023
• Study Completion: January 12, 2024
• Last Updated: March 12, 2025
• Results First Posted: March 12, 2025

Record last verified: 2024-09

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)