An interventional study of Cardiac computed tomography angiography and Standard of care management in Atrial Fibrillation (AF) and Atrial Flutter, sponsored by Ottawa Heart Institute Research Corporation. Recruiting at 3 sites in 2 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-09.
Sponsored by Ottawa Heart Institute Research Corporation · Not applicable, Interventional, and Diagnostic
The goal of this randomized clinical trial is to learn whether patients with symptomatic atrial fibrillation or atrial flutter (AF) who require heart imaging to rule out a blood clot before cardioversion would benefit from cardiac computed tomography angiography (CCT) in the emergency department (ED) compared to current standard of care management.
This will be a multicenter trial evaluating whether CCT-facilitated cardioversion in the ED reduces hospital admission, reduces repeat presentations to hospital and improves patient quality of life compared to the current standard of care.
Participants will undergo CCT-facilitated cardioversion or be treated according to current standard of care while in the ED and complete quality of life questionnaires in the ED and follow-up at 30 days.
Atrial fibrillation and atrial flutter (AF) are the most common cardiac arrhythmias worldwide resulting in frequent visits to the emergency department (ED). Some patients can undergo chemical or electrical cardioversion to restore their heart back to a sinus rhythm. However, if a patient is not on blood thinners and the duration of AF is prolonged then blood clots may form in the heart increasing the risk of stroke after cardioversion. Therefore, some patients must undergo heart imaging to rule out any blood clots before cardioversion is considered safe. Transesophageal echocardiography (TEE) is commonly used to rule out blood clots, but it is not readily available in all EDs often resulting in hospital admission to facilitate this test or deferring cardioversion until 3 weeks of blood thinners have been completed.
Cardiac computed tomography angiography (CCT) is a more readily available alternative to TEE that can be done rapidly in the ED. CCT has excellent sensitivity and specificity compared to TEE for identifying cardiac thrombus. If there is no thrombus detected on the CCT then patients could be immediately cardioverted to sinus rhythm thus avoiding an unnecessary hospital admission and reducing the symptom burden associated with remaining in AF.
This study is a multicenter randomized trial that will evaluate the effectiveness of using CCT facilitated cardioversion in the ED compared to current standard of care management.
4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.
This study's planned enrollment of 190 is above the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Ottawa Heart Institute Research Corporation is the lead sponsor of 182 studies on the registry; 42 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients in the control arm will be treated according to current standard of care as determined by the primary treating emergency department physician and may vary by institution and physician. Treatment in the standard of care group may include a rate control strategy with or without a planned cardioversion after 3 weeks of anticoagulation, deferring management for outpatient evaluation, request for TEE-facilitated cardioversion in the ED, or specialist consultation for further management or admission to hospital.
Other: Standard of care management
Patients in this arm will undergo cardiac computed tomography angiography (CCT) to evaluate for a left atrial/left atrial appendage (LA) thrombus. If the CCT shows no LA thrombus then the emergency department physician will be able to perform electrical and/or chemical cardioversion at their discretion. If the CCT shows a LA thrombus then cardioversion will be contraindicated and further management will be at the discretion of the treating physician.
Diagnostic Test: Cardiac computed tomography angiography
Patients will undergo CCT according to the following protocol. A non-contrast enhanced prospective ECG-triggered image will be acquired followed by a contrast-enhanced prospective ECG-triggered image using a tri-phasic contrast protocol. Delayed CT images 60 seconds after the initial contrast-enhanced CT scan will be obtained. Cardiac CT image interpretation will be performed according to routine clinical practices in a pragmatic fashion. The LA will be assessed for filling defects and characterized based upon attenuation values. If LA 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. If the CCT shows no LA thrombus then the ED physician will be able to perform electrical and/or chemical cardioversion at their discretion.
Patients in the standard of care arm may undergo any combination of the following management strategies in the emergency department (ED) at the discretion of their treating physician: 1\. Transesophageal echocardiogram (TEE) facilitated cardioversion; 2. Rate control; 3. Consultation with inpatient cardiac specialist for assessment/management and consideration of hospital admission; 4. cardioversion after 3 weeks of anticoagulation; and/or 5. Outpatient referral to cardiac specialist or general practitioner for further management.
Primary composite outcome
Using a hierarchical win ratio: 1. All-cause death 2. Stroke, transient ischemic attack, or systemic embolism 3. Admission to hospital for a cardiac or AF related reason 4. Repeat presentation to hospital for a cardiac or AF related reason 5. Improvement in AF Effect On Quality-Of-Life Questionnaire (AFEQT) quality of life greater than or equal to 5 points
Time frame: Randomization to 30 days
Composite objective outcomes
Using a hierarchical win ratio: 1. All-cause death 2. Stroke, transient ischemic attack, or systemic embolism 3. Admission to hospital for a cardiac or AF releated reason 4. Repeat presentation to hospital for a cardiac or AF related reason
Time frame: Randomization to 30 days
All-cause death
Death from any cause
Time frame: Randomization to 30 days
Cardiovascular death
Death due to a cardiovascular cause
Time frame: Randomization to 30 days
Stroke, transient ischemic attack, or systemic embolism
Stroke is defined as a central nervous system infarction of the brain, spinal cord, or retina in a vascular distribution based on pathologic, imaging, or clinical evidence with symptoms persisting for ≥24 hours or until death. Transient ischemic attack is defined as a transient episode of neurologic dysfunction due to focal brain, spinal cord, or retinal ischemia without acute infarction or tissue injury. Systemic embolism is defined as an abrupt vascular insufficiency associated with clinical or radiologic evidence of arterial occlusion in the absence of other likely mechanisms.
Time frame: Randomization to 30 days
Hospital admission for a cardiac or AF related reason
To count as a hospital admission for a cardiac or AF related reason it should meet the following criteria: 1. Duration of admission should exceed 24 hours; AND 2. Admission is due to the following reasons: * Admission at index hospital presentation: * Heart rate\>100bpm at rest or \>110bpm with ambulation despite a trial of rate control; or * Complication related to the treatment of AF (including significant incidental findings on CCT leading to admission) * Admission at subsequent hospital presentation: * Hospitalization due to a cardiac reason such as heart failure, syncope, palpitations/arrhythmia, angina or acute coronary syndrome
Time frame: Randomization to 30 days
Repeat presentation to the emergency department
Repeat presentation to the emergency department due to a cardiac reason such as heart failure, syncope, palpitations/arrhythmia, angina or acute coronary syndrome
Time frame: Randomization to 30 days
AFEQT quality of life
Change in AF Effect On Quality-Of-Life Questionnaire (AFEQT) quality of life The AFEQT is a 20-item, self-administered instrument that quantifies symptoms, daily activities, treatment concern, and treatment satisfaction. Scores are transformed to a range from 0-100, in which higher scores reflect better health status.
Time frame: Randomization to 30 days
SF-36 quality of life
Change in 36-Item Short Form Health Survey (SF-36) quality of life. The SF-36 questionnaire consists of eight scales yielding two summary measures: physical and mental health. The mental health measure is composed of vitality (4 items), social functioning (2 items), role-emotional (3 items), and mental health (5 items). Scores are transformed to a range of 0-100, in which higher scores reflect better health status.
Time frame: Randomization to 30 days
Bleeding
Bleeding events as defined by the Bleeding Academic Research Consortium
Time frame: Randomization to 30 days
Admission to hospital for acute kidney injury
Definition of acute kidney injury according to the Kidney Disease Improving Global Outcomes: * Increase in SCr by ≥ 0.3 mg/dl (≥ 26.5 µmol/l) within 48 hours; or * Increase in SCr to ≥ 1.5 times baseline, which is known or presumed to have occurred within the prior 7 days; or * Urine volume \<0.5 ml/kg/h for 6 hours
Time frame: Randomization to 30 days
Length of stay in the emergency department
Length of stay in emergency department in minutes, from time of arrival to time of discharge or admission
Time frame: From time of arrival until time of discharge or admission (approximately 3 hours)
Normal sinus rhythm
Being in normal sinus rhythm at the 30 day follow up. Heart rhythm will be determined by electrocardiography.
Time frame: Randomization to 30 days
Cost effectiveness
Cost effectiveness between CCT strategy and standard of care
Time frame: Emergency department presentation to 30 days
Plan to share: Yes — The study data, protocol, SAP, ICF, and CSR will be made available at study completion/publication.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: Study completion
Access criteria: The above will be made publicly available.
No publications or documents are linked to this record.
Started Jun 2025 (actual). Primary completion is estimated for Jun 2028, 36 months after the start.
Of 796 non-industry interventional studies with no phase under Atrial Fibrillation, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 21 and three quarters within 59. This study's planned 36 months is close to that.
Counting every sponsor, half of 1,051 studies reached it within 33 months; a quarter within 18 and three quarters within 54.
How these figures are worked out, and which studies are left out of them.
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