<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT02225730</url>
  </required_header>
  <id_info>
    <org_study_id>28213</org_study_id>
    <nct_id>NCT02225730</nct_id>
  </id_info>
  <brief_title>Imaging Collaterals in Acute Stroke (iCAS)</brief_title>
  <acronym>iCAS</acronym>
  <official_title>Imaging Collaterals in Acute Stroke</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Stanford University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Swedish Medical Center</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>University of Pittsburgh</agency>
      <agency_class>Other</agency_class>
    </collaborator>
  </sponsors>
  <source>Stanford University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Stroke is caused by a sudden blockage of a blood vessel that delivers blood to the brain.&#xD;
      Unblocking the blood vessel with a blood clot removal device restores blood flow and if done&#xD;
      quickly may prevent the disability that can be caused by a stroke.&#xD;
&#xD;
      However, not all stroke patients benefit from having their blood vessel unblocked.&#xD;
&#xD;
      The aim of this study is to determine if special brain imaging, called MRI, can be used to&#xD;
      identify which stroke patients are most likely to benefit from attempts to unblock their&#xD;
      blood vessel with a special blood clot removal device. In particular, we will assess in this&#xD;
      trial whether a noncontrast MR imaging sequence, arterial spin labeling (ASL), can&#xD;
      demonstrate the presence of collateral blood flow (compared with a gold standard of the&#xD;
      angiogram) and whether it is useful to predict who will benefit from treatment.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Intravenous tissue plasminogen activator (IV tPA) is the standard of care treatment for&#xD;
      stroke patients when treatment can be initiated within 3 hours after symptom onset.&#xD;
      Unfortunately, only a very small fraction of stroke patients is treated with tPA, and&#xD;
      benefits from tPA. This is the result of two main limitations of tPA therapy.&#xD;
&#xD;
      First, the proportion of patients that can be treated with iv tPA is small. Because of the&#xD;
      narrow three hour time-window during which tPA is effective, only patients who arrive to the&#xD;
      hospital early on can be treated with tPA. Most stroke patients, however, arrive at the&#xD;
      hospital after the three-hour time-window and are therefore excluded from tPA treatment.&#xD;
      Second, stroke patients who receive tPA do not always benefit because the treatment does not&#xD;
      restore blood flow in all patients.&#xD;
&#xD;
      Patients with persistent blood vessel occlusions and no improvement in their clinical&#xD;
      condition after receiving tPA or those arriving at the hospital outside the 3 hour time&#xD;
      window routinely undergo mechanical clot removal to open an occluded blood vessel in the&#xD;
      brain.&#xD;
&#xD;
      Mechanical clot removal increases the percentage of stroke patients who achieve&#xD;
      recanalization, and as a result may increase the proportion of patients who have good&#xD;
      clinical outcomes. However it is unclear for which stroke patients mechanical thrombectomy is&#xD;
      most suitable. Although effective at removing blood-clots, it appears that mechanical clot&#xD;
      retrieval is not beneficial for all patients. Whereas some patients benefit, others&#xD;
      experience no effect, and yet others are likely harmed by mechanical clot retrieval. In order&#xD;
      to avoid harm and maximize benefit it is important to know, prior to initiation of the&#xD;
      mechanical clot retrieval procedure, if the procedure is likely to result in a clinical&#xD;
      improvement. We hypothesize that the response to mechanical clot retrieval can be predicted&#xD;
      based on characteristics of an MRI scan obtained just prior to the retrieval procedure. In&#xD;
      particular, this study will assess whether a new non-contrast MR imaging method, arterial&#xD;
      spin labeling (ASL), which measures cerebral blood flow and can give insight into collateral&#xD;
      flow, is effective at predicting who will benefit most from treatment. The investigators hope&#xD;
      to learn if these new MRI techniques can help identify which patients are most likely to&#xD;
      benefit from mechanical clot removal after receiving tPA.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>September 2013</start_date>
  <completion_date type="Actual">October 31, 2019</completion_date>
  <primary_completion_date type="Actual">October 31, 2019</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Cohort</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>favorable clinical response</measure>
    <time_frame>day 30</time_frame>
    <description>A &quot;favorable clinical response&quot;, defined as an 8-point or more improvement on the NIH score when comparing the baseline score to the 30-day score or NIH score of 0 or a 30-day NIH score of 0-1</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>modified Rankin Score</measure>
    <time_frame>day 90</time_frame>
    <description>90 day modified Rankin Score 5-6 and 90 day modified Rankin distribution</description>
  </secondary_outcome>
  <enrollment type="Actual">187</enrollment>
  <condition>Stroke, Acute</condition>
  <eligibility>
    <study_pop>
      <textblock>
        Patients presenting to the hospital with diagnosis of acute ischemic stroke who are&#xD;
        scheduled to undergo (or have undergone) acute IA stroke therapy will be screened for study&#xD;
        enrollment.&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria&#xD;
&#xD;
          1. Age 18 and older&#xD;
&#xD;
          2. Clinical diagnosis of ischemic stroke and an associated score on the NIHSS of 5 or&#xD;
             more points&#xD;
&#xD;
          3. Planned to undergo (or has undergone) intra-arterial (IA) thrombectomy and/or&#xD;
             thrombolysis for acute hemispheric stroke. (Either as primary therapy or as adjuvant&#xD;
             therapy following intravenous tPA treatment)&#xD;
&#xD;
          4. Planned to undergo or has undergone an MR brain scan including MR perfusion imaging&#xD;
             (ASL &amp; bolus PWI) and MR angiography of the circle of Willis prior to IA therapy&#xD;
&#xD;
          5. Intra-arterial thrombectomy can be started within 90 minutes of completion of the MR&#xD;
             perfusion scan and within 24 hours of symptom onset (Start of IA therapy is defined as&#xD;
             the time of insertion of the femoral artery sheath; Time of brain scan is defined as&#xD;
             the time that the scan is completed)&#xD;
&#xD;
          6. Able to obtain informed consent&#xD;
&#xD;
        Exclusion Criteria&#xD;
&#xD;
          1. Any pre-existing illness resulting in a modified Rankin Scale Score of 2 or higher&#xD;
             prior to the qualifying stroke&#xD;
&#xD;
          2. Creatinine clearance &lt; 40 ml/min based on the NIDDK four-variable MDRD method&#xD;
             (non-weight based)&#xD;
&#xD;
          3. Documented allergy to MR contrast agent&#xD;
&#xD;
          4. MRI contraindications (pacemaker, etc.)&#xD;
&#xD;
          5. Pregnancy&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Gregory Zaharchuk, MD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Stanford University</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Eden Medical Center</name>
      <address>
        <city>Castro Valley</city>
        <state>California</state>
        <zip>94546</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Stanford University Medical Center</name>
      <address>
        <city>Stanford</city>
        <state>California</state>
        <zip>94035</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>University of Pittsburgh</name>
      <address>
        <city>Pittsburgh</city>
        <state>Pennsylvania</state>
        <zip>15213</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Swedish Hospital</name>
      <address>
        <city>Seattle</city>
        <state>Washington</state>
        <zip>98122</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>United States</country>
  </location_countries>
  <verification_date>March 2020</verification_date>
  <study_first_submitted>August 22, 2014</study_first_submitted>
  <study_first_submitted_qc>August 22, 2014</study_first_submitted_qc>
  <study_first_posted type="Estimate">August 26, 2014</study_first_posted>
  <last_update_submitted>March 17, 2020</last_update_submitted>
  <last_update_submitted_qc>March 17, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">March 19, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Stanford University</investigator_affiliation>
    <investigator_full_name>Greg Zaharchuk</investigator_full_name>
    <investigator_title>Assistant Professor of Radiology</investigator_title>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Stroke</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT02225730
org study id: 28213
nct id: NCT02225730
lead sponsor: 
collaborator: 
collaborator: 
has dmc: No
Stroke is caused by a sudden blockage of a blood vessel that delivers blood to the brain.
      Unblocking the blood vessel with a blood clot removal device restores blood flow and if done
      quickly may prevent the disability that can be caused by a stroke.

      However, not all stroke patients benefit from having their blood vessel unblocked.

      The aim of this study is to determine if special brain imaging, called MRI, can be used to
      identify which stroke patients are most likely to benefit from attempts to unblock their
      blood vessel with a special blood clot removal device. In particular, we will assess in this
      trial whether a noncontrast MR imaging sequence, arterial spin labeling (ASL), can
      demonstrate the presence of collateral blood flow (compared with a gold standard of the
      angiogram) and whether it is useful to predict who will benefit from treatment.
Intravenous tissue plasminogen activator (IV tPA) is the standard of care treatment for
      stroke patients when treatment can be initiated within 3 hours after symptom onset.
      Unfortunately, only a very small fraction of stroke patients is treated with tPA, and
      benefits from tPA. This is the result of two main limitations of tPA therapy.

      First, the proportion of patients that can be treated with iv tPA is small. Because of the
      narrow three hour time-window during which tPA is effective, only patients who arrive to the
      hospital early on can be treated with tPA. Most stroke patients, however, arrive at the
      hospital after the three-hour time-window and are therefore excluded from tPA treatment.
      Second, stroke patients who receive tPA do not always benefit because the treatment does not
      restore blood flow in all patients.

      Patients with persistent blood vessel occlusions and no improvement in their clinical
      condition after receiving tPA or those arriving at the hospital outside the 3 hour time
      window routinely undergo mechanical clot removal to open an occluded blood vessel in the
      brain.

      Mechanical clot removal increases the percentage of stroke patients who achieve
      recanalization, and as a result may increase the proportion of patients who have good
      clinical outcomes. However it is unclear for which stroke patients mechanical thrombectomy is
      most suitable. Although effective at removing blood-clots, it appears that mechanical clot
      retrieval is not beneficial for all patients. Whereas some patients benefit, others
      experience no effect, and yet others are likely harmed by mechanical clot retrieval. In order
      to avoid harm and maximize benefit it is important to know, prior to initiation of the
      mechanical clot retrieval procedure, if the procedure is likely to result in a clinical
      improvement. We hypothesize that the response to mechanical clot retrieval can be predicted
      based on characteristics of an MRI scan obtained just prior to the retrieval procedure. In
      particular, this study will assess whether a new non-contrast MR imaging method, arterial
      spin labeling (ASL), which measures cerebral blood flow and can give insight into collateral
      flow, is effective at predicting who will benefit most from treatment. The investigators hope
      to learn if these new MRI techniques can help identify which patients are most likely to
      benefit from mechanical clot removal after receiving tPA.
observational model: Cohort
time perspective: Prospective
measure: favorable clinical response
time frame: day 30
description: A "favorable clinical response", defined as an 8-point or more improvement on the NIH score when comparing the baseline score to the 30-day score or NIH score of 0 or a 30-day NIH score of 0-1
measure: modified Rankin Score
time frame: day 90
description: 90 day modified Rankin Score 5-6 and 90 day modified Rankin distribution
study pop: 
sampling method: Probability Sample
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: No
last name: Gregory Zaharchuk, MD
role: Principal Investigator
affiliation: Stanford University
facility: 
facility: 
facility: 
facility: 
country: United States
responsible party type: Principal Investigator
investigator affiliation: Stanford University
investigator full name: Greg Zaharchuk
investigator title: Assistant Professor of Radiology
mesh term: Stroke