xml: <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/NCT06007469</url>
    </required_header>
    <id_info>
      <org_study_id>SP0721</org_study_id>
      <nct_id>NCT06007469</nct_id>
    </id_info>
    <brief_title>Pedal Acceleration Time (PAT) as a Measure of Foot Perfusion</brief_title>
    <acronym>PAT</acronym>
    <official_title>Pedal Acceleration Time (PAT) Versus Toe Brachial Pressure Index (TBPI) as a Measure of Foot Perfusion - A Pilot Study.</official_title>
    <sponsors>
      <lead_sponsor>
        <agency>Liverpool University Hospitals NHS Foundation Trust</agency>
        <agency_class>Other</agency_class>
      </lead_sponsor>
    </sponsors>
    <source>Liverpool University Hospitals NHS Foundation Trust</source>
    <oversight_info>
      <has_dmc>No</has_dmc>
      <is_fda_regulated_drug>No</is_fda_regulated_drug>
      <is_fda_regulated_device>No</is_fda_regulated_device>
    </oversight_info>
    <brief_summary>
      <textblock>
        To identify a correlation between Toe Brachial pressure Index (TBPI) and Acceleration time of&#xD;
        the pedal vessels. The aim would then to use this data to design a clinical study assessing&#xD;
        the relationship between PAT and wound healing in patients with PAD.&#xD;
      </textblock>
    </brief_summary>
    <detailed_description>
      <textblock>
        The use of ankle brachial pressure index (ABPI) is commonplace in the screening, diagnosis&#xD;
        and management of peripheral vascular disease (PAD). This technique measures and compares the&#xD;
        occlusion pressure of the brachial arteries for comparison with the occlusion pressure of the&#xD;
        tibial arteries at the level of the ankle. The index is then calculated by dividing the&#xD;
        highest of the tibial occlusion pressures by the highest brachial occlusion pressure. In&#xD;
        normal subjects the ABPI should fall between 09-1.3 (1) . A pressure less than 0.9 suggest a&#xD;
        compromise to the peripheral circulation (PAD), with the blood pressure at the ankle level&#xD;
        being lower than in the arm. ABPI results can be erroneous in the presence of medial artery&#xD;
        calcification (MAC) where the ankle arteries are more difficult to compress and hence give&#xD;
        falsely elevated readings. In some patients it can be impossible to occlude the arterial flow&#xD;
        as the vessel is so rigid (1). Conditions that increase the prevalence of MAC are diabetes&#xD;
        mellitus, chronic kidney disease as well as advancing age which also increased the stiffness&#xD;
        of the vessel walls having a similar effect as MAC (2).&#xD;
  &#xD;
        When used in isolation as a PAD screening, ABPI can give a normal reading due to undiagnosed&#xD;
        pathological vessel stiffness with studies reporting up to 14-27% of patients returning&#xD;
        normal ABPI results at the same time as low TBPI. (3) Despite the potential pitfall of ABPI,&#xD;
        it is still a widely recognized as its diagnostic limits have been validated in several large&#xD;
        scale studies. (3) However, due to the level of arterial assessment, ABPI does not actually&#xD;
        assess circulation into the foot itself (4). The toe vessels are much less susceptible to&#xD;
        vessel stiffness (3) , and hence deemed are more reliable in such cases when the ABPI would&#xD;
        return a falsely elevated result.&#xD;
  &#xD;
        When used alongside detailed duplex imaging of the peripheral arterial tree to give image&#xD;
        guided documentation of vessel calcification, TBPI is a useful indicator of perfusion into&#xD;
        the foot when the ABPI is known not to be indicated. Therefore TBPI measurement has become&#xD;
        the established method for assessing arterial perfusion to the foot, particularly in patients&#xD;
        with risk factors for MAC.&#xD;
  &#xD;
        When investigating perfusion into the critically ischaemic limb, ABPI is not indicated and&#xD;
        therefore TBPI is the preferred method. However this becomes problematic when there has been&#xD;
        previous amputation of the forefoot/toes, the patient is in significant pain and/or there is&#xD;
        tissue loss which impedes accurate placement of the equipment on the affected limb.&#xD;
        Furthermore, in a significant number of these patients it is not possible to obtain an&#xD;
        adequate waveform in the toe due to poor arterial perfusion.&#xD;
  &#xD;
        To overcome this predicament a novel technique has been developed which involves direct&#xD;
        ultrasound imaging of the pedal vasculature and use the systolic rise time calculated from&#xD;
        the returned waveform analysis as a surrogate for ABPI (4) This systolic rise time, known as&#xD;
        pedal acceleration time (PAT) in foot vessels, has been has been reported to correlate well&#xD;
        with ABPI in patients with compressible vessels and therefore is felt to be a predictor of&#xD;
        wound healing following direct and indirect revascularization. (4) There are, however, a&#xD;
        significant group of patients that attend the vascular department that have risk factors for&#xD;
        MAC which make them unsuitable for ABPI. For this group of patients and those with coexisting&#xD;
        with foot wounds/previous amputation, there is no ratified method for investigation perfusion&#xD;
        pressure.&#xD;
  &#xD;
        The aim of this pilot study is to gather information from all patients who present with&#xD;
        significant PAD to investigate a possible link between PAT, ABPI and TBPI and if PAT is a&#xD;
        reliable measurement in patients who fall outside of the group normally excluded.&#xD;
  &#xD;
        This would allow objective perfusion information and therefore guide treatment and management&#xD;
        plans.&#xD;
      </textblock>
    </detailed_description>
    <overall_status>Not yet recruiting</overall_status>
    <start_date type="Anticipated">October 4, 2023</start_date>
    <completion_date type="Anticipated">December 3, 2024</completion_date>
    <primary_completion_date type="Anticipated">December 10, 2023</primary_completion_date>
    <study_type>Observational [Patient Registry]</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>
    <target_duration>1 Day</target_duration>
    <primary_outcome>
      <measure>Foot Perfusion.</measure>
      <time_frame>1 measure</time_frame>
      <description>ankle arterial acceleration time versus toe pressure (mmHg) Manual blood pressures of at the toe (mmHg) will also be measured from all participants, where technically possible.</description>
    </primary_outcome>
    <number_of_groups>2</number_of_groups>
    <enrollment type="Anticipated">50</enrollment>
    <condition>Critical Limb Ischemia</condition>
    <condition>Claudication, Intermittent</condition>
    <arm_group>
      <arm_group_label>Critical Limb Threatening Ischaemia</arm_group_label>
      <description>Patients presenting with Critical Limb Threatening Ischaemia</description>
    </arm_group>
    <arm_group>
      <arm_group_label>Non-limb threatening peripheral vascular disease</arm_group_label>
      <description>Patients presenting with non-limb threatening peripheral vascular disease</description>
    </arm_group>
    <eligibility>
      <study_pop>
        <textblock>
          patients will be identified who attend the vascular clinic at the Royal Liverpool Hospital.&#xD;
          The first 30 patients with critical limb threatening ischaemia (CLTI) that are identified&#xD;
          and consent for the study will be recruited. Similarly the first 20 patients who have&#xD;
          symptoms suggestive of non-critical, peripheral arterial disease such as intermittent&#xD;
          claudication will be recruited.&#xD;
        </textblock>
      </study_pop>
      <sampling_method>Probability Sample</sampling_method>
      <criteria>
        <textblock>
          Inclusion Criteria:&#xD;
  &#xD;
            -  1. Male/Female 2. Adults aged 18 and above 3. Willing to provide written, informed&#xD;
               consent 4. Referred into the vascular service with symptoms or confirmed PVD/CLTI&#xD;
  &#xD;
          Exclusion Criteria:&#xD;
  &#xD;
            1. Referral not indicative of PVD&#xD;
  &#xD;
            2. Occlusion of vessels/no visible flow at the site of interest&#xD;
  &#xD;
            3. Amputation of the limb&#xD;
  &#xD;
            4. Tissue loss preventing assessment&#xD;
        </textblock>
      </criteria>
      <gender>All</gender>
      <minimum_age>18 Years</minimum_age>
      <maximum_age>N/A</maximum_age>
      <healthy_volunteers>No</healthy_volunteers>
    </eligibility>
    <verification_date>August 2023</verification_date>
    <study_first_submitted>May 27, 2022</study_first_submitted>
    <study_first_submitted_qc>August 22, 2023</study_first_submitted_qc>
    <study_first_posted type="Actual">August 23, 2023</study_first_posted>
    <last_update_submitted>August 22, 2023</last_update_submitted>
    <last_update_submitted_qc>August 22, 2023</last_update_submitted_qc>
    <last_update_posted type="Actual">August 23, 2023</last_update_posted>
    <responsible_party>
      <responsible_party_type>Sponsor</responsible_party_type>
    </responsible_party>
    <keyword>ischaemia</keyword>
    <keyword>ABPI</keyword>
    <keyword>TBPI</keyword>
    <keyword>claudication</keyword>
    <keyword>ulceration</keyword>
    <keyword>acceleration time</keyword>
    <keyword>duplex ultrasound</keyword>
    <condition_browse>
      <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
      <mesh_term>Chronic Limb-Threatening Ischemia</mesh_term>
      <mesh_term>Intermittent Claudication</mesh_term>
      <mesh_term>Ischemia</mesh_term>
    </condition_browse>
    <!-- Results have not yet been posted for this study                                          -->
  </clinical_study>
  
  
text: 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/NCT06007469
  org study id: SP0721
  nct id: NCT06007469
  lead sponsor: 
  has dmc: No
  is fda regulated drug: No
  is fda regulated device: No
  To identify a correlation between Toe Brachial pressure Index (TBPI) and Acceleration time of
        the pedal vessels. The aim would then to use this data to design a clinical study assessing
        the relationship between PAT and wound healing in patients with PAD.
  The use of ankle brachial pressure index (ABPI) is commonplace in the screening, diagnosis
        and management of peripheral vascular disease (PAD). This technique measures and compares the
        occlusion pressure of the brachial arteries for comparison with the occlusion pressure of the
        tibial arteries at the level of the ankle. The index is then calculated by dividing the
        highest of the tibial occlusion pressures by the highest brachial occlusion pressure. In
        normal subjects the ABPI should fall between 09-1.3 (1) . A pressure less than 0.9 suggest a
        compromise to the peripheral circulation (PAD), with the blood pressure at the ankle level
        being lower than in the arm. ABPI results can be erroneous in the presence of medial artery
        calcification (MAC) where the ankle arteries are more difficult to compress and hence give
        falsely elevated readings. In some patients it can be impossible to occlude the arterial flow
        as the vessel is so rigid (1). Conditions that increase the prevalence of MAC are diabetes
        mellitus, chronic kidney disease as well as advancing age which also increased the stiffness
        of the vessel walls having a similar effect as MAC (2).
  
        When used in isolation as a PAD screening, ABPI can give a normal reading due to undiagnosed
        pathological vessel stiffness with studies reporting up to 14-27% of patients returning
        normal ABPI results at the same time as low TBPI. (3) Despite the potential pitfall of ABPI,
        it is still a widely recognized as its diagnostic limits have been validated in several large
        scale studies. (3) However, due to the level of arterial assessment, ABPI does not actually
        assess circulation into the foot itself (4). The toe vessels are much less susceptible to
        vessel stiffness (3) , and hence deemed are more reliable in such cases when the ABPI would
        return a falsely elevated result.
  
        When used alongside detailed duplex imaging of the peripheral arterial tree to give image
        guided documentation of vessel calcification, TBPI is a useful indicator of perfusion into
        the foot when the ABPI is known not to be indicated. Therefore TBPI measurement has become
        the established method for assessing arterial perfusion to the foot, particularly in patients
        with risk factors for MAC.
  
        When investigating perfusion into the critically ischaemic limb, ABPI is not indicated and
        therefore TBPI is the preferred method. However this becomes problematic when there has been
        previous amputation of the forefoot/toes, the patient is in significant pain and/or there is
        tissue loss which impedes accurate placement of the equipment on the affected limb.
        Furthermore, in a significant number of these patients it is not possible to obtain an
        adequate waveform in the toe due to poor arterial perfusion.
  
        To overcome this predicament a novel technique has been developed which involves direct
        ultrasound imaging of the pedal vasculature and use the systolic rise time calculated from
        the returned waveform analysis as a surrogate for ABPI (4) This systolic rise time, known as
        pedal acceleration time (PAT) in foot vessels, has been has been reported to correlate well
        with ABPI in patients with compressible vessels and therefore is felt to be a predictor of
        wound healing following direct and indirect revascularization. (4) There are, however, a
        significant group of patients that attend the vascular department that have risk factors for
        MAC which make them unsuitable for ABPI. For this group of patients and those with coexisting
        with foot wounds/previous amputation, there is no ratified method for investigation perfusion
        pressure.
  
        The aim of this pilot study is to gather information from all patients who present with
        significant PAD to investigate a possible link between PAT, ABPI and TBPI and if PAT is a
        reliable measurement in patients who fall outside of the group normally excluded.
  
        This would allow objective perfusion information and therefore guide treatment and management
        plans.
  observational model: Cohort
  time perspective: Prospective
  measure: Foot Perfusion.
  time frame: 1 measure
  description: ankle arterial acceleration time versus toe pressure (mmHg) Manual blood pressures of at the toe (mmHg) will also be measured from all participants, where technically possible.
  arm group label: Critical Limb Threatening Ischaemia
  description: Patients presenting with Critical Limb Threatening Ischaemia
  arm group label: Non-limb threatening peripheral vascular disease
  description: Patients presenting with non-limb threatening peripheral vascular disease
  study pop: 
  sampling method: Probability Sample
  criteria: 
  gender: All
  minimum age: 18 Years
  maximum age: N/A
  healthy volunteers: No
  responsible party type: Sponsor
  mesh term: Chronic Limb-Threatening Ischemia
  mesh term: Intermittent Claudication
  mesh term: Ischemia