StrokeNCT02405845
Prospective Evaluation of Carotid Free-floating Thrombus
A study testing Computed Tomographic Angiogram in people with Stroke and Transient Ischemic Attack, run by Ottawa Hospital Research Institute at 1 site in Canada.
Trial summary
Hardened plaque located in the carotid arteries can cause stroke or transient ischemic attack (TIA). This type of plaque is linked to unstable free-floating thrombi (FFT). FFT are blood clots that form in a blood vessel, and are at the highest risk for travelling within the bloodstream and causing strokes. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Stroke, Transient Ischemic Attack
- What is being tested?
- Computed Tomographic Angiogram
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteCanada
- Study dates
- Mar 2015to Sep 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- TIA/Stroke within 72 hours
- CTA showing a symptom-relevant ICA lesion (stenosis >50%)
- informed consent
Who cannot join
- creatinine clearance <60 mg/ml
- allergy to contrast media
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Prospective Evaluation of Intraluminal Internal Carotid Artery Free-Floating Thrombus
Hardened plaque located in the carotid arteries can cause stroke or transient ischemic attack (TIA). This type of plaque is linked to unstable free-floating thrombi (FFT). FFT are blood clots that form in a blood vessel, and are at the highest risk for travelling within the bloodstream and causing strokes. Physicians are able to see this type of plaque with computed tomographic angiography (CTA) but FFT look very similar to stable types of plaque that do not require urgent treatment.
Distinguishing between these plaques is important because it affects the choice and urgency of treatment that patients receive.
The researchers have found a promising visual marker on CTA scans. The goal of this study is to determine if this visual marker seen on CTA scans will help to distinguish FFT plaque from stable plaque.
Read the detailed description
Atherosclerotic plaques at the origin of the internal carotid artery (ICA) can cause TIA/stroke, and are well-visualized with CT angiography (CTA). Those plaques associated with unstable free-floating thrombi (FFT) are at highest risk for embolization and stroke. Unfortunately, FFT have a similar appearance to stable ulcerated plaques on CTA: both appear as intraluminal filling defects of varying length and morphology. Distinguishing these entities is critical as it affects the choice and urgency of treatment (antithrombotics vs revascularization). Using a retrospective study, we have previously proposed a promising CTA imaging marker to distinguish FFT from stable ulcerated plaque. It is hoped that after the data is collected from this prospective study to one day initiate a multi-centre study.
In our prior research, we proposed a reasonable "gold standard" for FFT diagnosis. We followed patients presenting with circular filling defects on CTA (doughnut signs) suspicious for either FFT or ulcerated plaque with serial CTAs after medical therapy. Those that diminished or resolved with antithrombotic treatment (or those that unfortunately "resolved" by embolizing distally) were presumed to be "true FFT" in contrast to those that remained unchanged. We then assessed the performance of a variety of imaging parameters to differentiate FFT from ulcerated plaque: we tested linear measurements, morphology, degree of stenosis, as well as relevant clinical factors. These parameters were measured by neuroradiologists as well as an innovative semi-automated shape analysis. Using a retrospectively established cohort, we were able to derive 3.8 mm as an optimal cranial-caudal length threshold of the filling defect that can potentially help distinguish FFT from plaque, with 88% sensitivity and 86% specificity.
We will prospectively identify consecutive patients presenting with TIA/stroke within 72 hrs of symptom onset with an ICA intraluminal filling defect on CTA. We will review the imaging data and measure the cranial-caudal length of the filling defect. Patients will receive a follow-up CTA in one week as per the current clinical standard of care, and if the defect is still unresolved, a third CTA will be repeated after a second week if unresolved, and a fourth at one month (research). We will measure cranial-caudal length of the filling defect at each time interval, blind to the previous measurements. Resolution of the filling defect at any point is diagnostic of FFT, whereas its static appearance after 1 month is diagnostic of ulcerated plaque. For this pilot study, measure rate of enrolment, adherence to study protocols, attrition rates, and proportion of patients with FFT. For the exploratory objective, we will record treatment choice, dose, and duration.
- Conditions
- Stroke, Transient Ischemic Attack
- Being tested
- Computed Tomographic Angiogram
- Keywords
- Atherosclerosis, Internal Carotid Artery, Free-floating thrombus, Ulcerated plaque, FFT
- Medical subject headings
- Stroke, Ischemic Attack, Transient, Atherosclerosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Computed Tomographic AngiogramRadiation
Also called CTA, CT Angiogram
1 additional non-clinical CTA per patient enrolled in the study. The estimated radiation risk from a single CTA of the neck and brain is approximately 3.6 millisieverts (mSv), an exposure similar to a single airplane flight across Canada.
| Study group | Role | What they receive |
|---|---|---|
| CT Angiogram | Other | A research CTA scan may be required if there is no change of the imaging on the 3 CTA scans prior. Receives: Radiation: Computed Tomographic Angiogram |
What is being measured
The primary outcome is the main question the study is designed to answer.
Length of intraluminal filling defect on CTA as a measure to distinguish FFT from stable ulcerated plaque
Measured: 12 months
Secondary outcomes (3)
Prevalence of FFT among patients with ambiguous diagnosis measured by follow-up CTA scans
Measured: 12 months
Clinician treatment strategies used to manage FFT
Measured: 18 months
Future antithrombotic treatment trial measured by data collection tools and pilot data
Measured: 18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Apr 2015 (estimated)
- Study startMar 2015
- Primary completionJun 2021
- Study completionSep 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for StrokeStudies of the same condition, open and under way.
- More trials run by Ottawa Hospital Research InstituteThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 100 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ottawa Hospital Research Institute
- Sponsor type
- University, hospital or other
- Collaborators
- The Ottawa Hospital
- Responsible party
- Sponsor
- Investigators
- Carlos Torres, MD, Principal investigator, Ottawa Hospital Research Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02405845
- Sponsor's protocol ID
- OHSN-REB 20150092-01H
- Status last verified
- Oct 2021
- First submitted
- 11 Mar 2015
- Last updated
- 14 Oct 2021
- Results posted
- No
- Data monitoring committee
- No
Publications
Torres C, Lum C, Puac-Polanco P, Stotts G, Shamy MCF, Blacquiere D, Lun R, Dave P, Bharatha A, Menon BK, Thornhill R, Momoli F, Dowlatshahi D. Differentiating Carotid Free-Floating Thrombus From Atheromatous Plaque Using Intraluminal Filling Defect Length on CTA: A Validation Study. Neurology. 2021 Aug 24;97(8):e785-e793. doi: 10.1212/WNL.0000000000012368. Epub 2021 Jun 14.
PubMed 34426550
Study at a glance
From the registry record, last updated by the sponsor on 14 Oct 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective Evaluation of Intraluminal Internal Carotid Artery Free-Floating Thrombus
- ClinicalTrials.gov ID
- NCT02405845
- Acronym / sponsor ID
- OHSN-REB 20150092-01H
- Conditions
- Stroke, Transient Ischemic Attack
- Keywords
- Atherosclerosis, Internal Carotid Artery, Free-floating thrombus, Ulcerated plaque, FFT
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 100 participants (actual)
- Lead sponsor
- Ottawa Hospital Research InstituteUniversity, hospital or other
- Collaborators
- The Ottawa Hospital
- Study start
- Mar 2015 (actual)
- Primary completion
- Jun 2021 (actual)
- Study completion
- Sep 2021 (actual)
- First posted
- 1 Apr 2015 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Hardened plaque located in the carotid arteries can cause stroke or transient ischemic attack (TIA). This type of plaque is linked to unstable free-floating thrombi (FFT). FFT are blood clots that form in a blood vessel, and are at the highest risk for travelling within the bloodstream and causing strokes. Physicians are able to see this type of plaque with computed tomographic angiography (CTA) but FFT look very similar to stable types of plaque that do not require urgent treatment.
Distinguishing between these plaques is important because it affects the choice and urgency of treatment that patients receive.
The researchers have found a promising visual marker on CTA scans. The goal of this study is to determine if this visual marker seen on CTA scans will help to distinguish FFT plaque from stable plaque.
Detailed description
Atherosclerotic plaques at the origin of the internal carotid artery (ICA) can cause TIA/stroke, and are well-visualized with CT angiography (CTA). Those plaques associated with unstable free-floating thrombi (FFT) are at highest risk for embolization and stroke. Unfortunately, FFT have a similar appearance to stable ulcerated plaques on CTA: both appear as intraluminal filling defects of varying length and morphology. Distinguishing these entities is critical as it affects the choice and urgency of treatment (antithrombotics vs revascularization). Using a retrospective study, we have previously proposed a promising CTA imaging marker to distinguish FFT from stable ulcerated plaque. It is hoped that after the data is collected from this prospective study to one day initiate a multi-centre study.
In our prior research, we proposed a reasonable "gold standard" for FFT diagnosis. We followed patients presenting with circular filling defects on CTA (doughnut signs) suspicious for either FFT or ulcerated plaque with serial CTAs after medical therapy. Those that diminished or resolved with antithrombotic treatment (or those that unfortunately "resolved" by embolizing distally) were presumed to be "true FFT" in contrast to those that remained unchanged. We then assessed the performance of a variety of imaging parameters to differentiate FFT from ulcerated plaque: we tested linear measurements, morphology, degree of stenosis, as well as relevant clinical factors. These parameters were measured by neuroradiologists as well as an innovative semi-automated shape analysis. Using a retrospectively established cohort, we were able to derive 3.8 mm as an optimal cranial-caudal length threshold of the filling defect that can potentially help distinguish FFT from plaque, with 88% sensitivity and 86% specificity.
We will prospectively identify consecutive patients presenting with TIA/stroke within 72 hrs of symptom onset with an ICA intraluminal filling defect on CTA. We will review the imaging data and measure the cranial-caudal length of the filling defect. Patients will receive a follow-up CTA in one week as per the current clinical standard of care, and if the defect is still unresolved, a third CTA will be repeated after a second week if unresolved, and a fourth at one month (research). We will measure cranial-caudal length of the filling defect at each time interval, blind to the previous measurements. Resolution of the filling defect at any point is diagnostic of FFT, whereas its static appearance after 1 month is diagnostic of ulcerated plaque. For this pilot study, measure rate of enrolment, adherence to study protocols, attrition rates, and proportion of patients with FFT. For the exploratory objective, we will record treatment choice, dose, and duration.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| CT Angiogram | Other | Radiation: Computed Tomographic AngiogramA research CTA scan may be required if there is no change of the imaging on the 3 CTA scans prior. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (3 listed)
- TIA/Stroke within 72 hours
- CTA showing a symptom-relevant ICA lesion (stenosis >50%)
- informed consent
Key exclusion criteria (2 listed)
- creatinine clearance <60 mg/ml
- allergy to contrast media
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Computed Tomographic AngiogramAlso: CTA, CT Angiogram1 additional non-clinical CTA per patient enrolled in the study. The estimated radiation risk from a single CTA of the neck and brain is approximately 3.6 millisieverts (mSv), an exposure similar to a single airplane flight across Canada. | Radiation | CT Angiogram |
Primary outcome
Length of intraluminal filling defect on CTA as a measure to distinguish FFT from stable ulcerated plaque
Time frame: 12 months
3 secondary outcomes
Prevalence of FFT among patients with ambiguous diagnosis measured by follow-up CTA scans
Time frame: 12 months
Clinician treatment strategies used to manage FFT
Time frame: 18 months
Future antithrombotic treatment trial measured by data collection tools and pilot data
Time frame: 18 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Oct 2021.
- Derived from this study: PubMed 34426550Torres C, Lum C, Puac-Polanco P, Stotts G, Shamy MCF, Blacquiere D, Lun R, Dave P, Bharatha A, Menon BK, Thornhill R, Momoli F, Dowlatshahi D. Differentiating Carotid Free-Floating Thrombus From Atheromatous Plaque Using Intraluminal Filling Defect Length on CTA: A Validation Study. Neurology. 2021 Aug 24;97(8):e785-e793. doi: 10.1212/WNL.0000000000012368. Epub 2021 Jun 14.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Carlos Torres, MD principal investigator
Ottawa Hospital Research Institute
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Computed Tomographic Angiogram in people with Stroke and Transient Ischemic Attack, run by Ottawa Hospital Research Institute at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Oct 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Length of intraluminal filling defect on CTA as a measure to distinguish FFT from stable ulcerated plaque (time frame: 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02405845, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Oct 2021.