NCT05518305 · University of California, Los Angeles
Platelet Expression of FcγRIIa and Arterial Hemodynamics to Predict Recurrent Stroke in Intracranial Atherosclerosis
(FCG)
What this study is about
An observational study to determine if individuals with increased platelet FcyRIIa will have a higher risk of ischemic events.
View original scientific description
An observational study to determine if individuals with increased platelet FcyRIIa will have a higher risk of ischemic events.
Interventions
DIAGNOSTIC_TEST
Medical Imaging
magnetic resonance imaging
Primary outcome measures
Determine the impact of platelet FcγRIIa expression on 1-year risk of recurrent stroke in ICAD.
Time frame: 1 year
The investigators hypothesize that increased platelet FcγRIIa will be associated with a greater risk of ischemic events. Platelet FcγRIIa expression will be quantified in 250 subjects enrolled at 6 sites with stroke or TIA due to 50-99% ICAD to determine impact of FcγRIIa on 1-year risk of recurrent stroke, including clinical events and serial MRI.
Quantify the impact of WSS from CTA CFD on 1-year risk of recurrent stroke in ICAD
Time frame: 1 year
The investigators hypothesize that high WSS and an elevated post-stenotic oscillatory shear index (OSI) that are stimuli of shear-induced platelet aggregation will confer an increased risk of recurrent ischemic stroke. We will use routinely acquired CTA in 250 subjects enrolled at 6 sites with stroke or TIA due to 50-99% ICAD to quantify the impact of WSS and post-stenotic OSI on 1-year risk of recurrent stroke, including clinical events and serial MRI.
Develop a precision model to determine the risk of recurrent stroke 1 year after index events due to ICAD based on individual FcγRIIa expression and WSS from baseline CTA.
Time frame: 1 year
The investigators hypothesize that the 1-year recurrent stroke risk associated with high platelet FcγRIIa expression and high WSS will be more than additive.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Stroke is defined as symptoms lasting \>24 hours and associated with imaging evidence of acute ischemia in the distribution of the stenotic vessel on head CT or brain MRI. Minor stroke is defined as NIHSS\<6, as used in prior studies.
- Eligible TIA, defined as transient neurological symptoms lasting \<24 hours, need to be: a) accompanied by DWI abnormalities in the distribution of the stenotic artery; or b) multiple (\>1), stereotyped events associated with unequivocal ischemic symptoms (i.e. weakness, aphasia, diplopia), and attributed to the symptomatic artery. The intent of these restrictive inclusion criteria for TIA is to exclude potential stroke mimics.
- ICAD should involve the intracranial carotid, middle cerebral, intracranial vertebral or basilar arteries. Isolated anterior and posterior cerebral artery stenosis is not included as it is uncommon in these locations and non-invasive criteria for high-grade ICAD are not well established for these vessels.
- Stenosis 50-99% will be quantified by CTA. The criteria for 50-99% are: measured stenosis by WASID criteria (percent stenosis = (1-\[diameter stenosis/diameter normal\]) x 100%.
- Age ³30; those 30-49 years of age must also have the presence of established atherosclerotic disease in another vascular bed (coronary, extracranial carotid, peripheral) or the presence of 2 or more risk factors (hypertension, diabetes mellitus, hyperlipidemia, tobacco abuse within the last 2 years). The rationale for this criterion is to exclude non-atherosclerotic vasculopathies.
- Provide informed consent for participation in the study.
Exclusion criteria
- Other determined etiology or established cause of the acute stroke or TIA: atrial fibrillation, mitral stenosis, mechanical valve, intracardiac thrombus or vegetation, dilated cardiomyopathy or ejection fraction \<30%, proximal extracranial carotid or vertebral stenosis \>50%.
- Contraindications to MRI, including MR-incompatible metallic implants (i.e. certain artificial cardiac valves, penile implants, other prosthesis), implanted electronic devices (i.e. pacemaker/defibrillator, neurostimulators, cochlear implants), other potentially mobile ferromagnetic material (i.e. shrapnel, magnetic aneurysm clips), pregnancy (women in fertile age should have a negative pregnancy test), lactation, morbid obesity, and severe claustrophobia.
Where
- Los Angeles, California
Collaborators
University of Pittsburgh Medical Center, University of Chicago, Bay State Clinical Trials, Inc., Yale University, University of Vermont, University of Southern California
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
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How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 11, 2026 · Source of record for eligibility and locations