<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/NCT02973308</url>
  </required_header>
  <id_info>
    <org_study_id>199037</org_study_id>
    <nct_id>NCT02973308</nct_id>
  </id_info>
  <brief_title>The Inter and Intra Reliability of Cardiopulmonary Exercise Testing in Abdominal Aortic Aneurysm Patients</brief_title>
  <acronym>CPEX</acronym>
  <official_title>The Inter and Intra Reliability of Cardiopulmonary Exercise Testing in Abdominal Aortic Aneurysm Patients</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Hull University Teaching Hospitals NHS Trust</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>University of Hull</agency>
      <agency_class>Other</agency_class>
    </collaborator>
  </sponsors>
  <source>Hull University Teaching Hospitals NHS Trust</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Exercise testing is commonly being used in patients before surgery to test their overall&#xD;
      fitness. One group it is being used in is patients who have an enlarged blood vessel in their&#xD;
      stomach. This is known as an abdominal aortic aneurysm. The exercise test used is known as a&#xD;
      cardiopulmonary exercise test as it looks at both heart and lung function at the same time.&#xD;
      Whilst this test is commonly used there have been no studies (to date) which have looked at&#xD;
      how reliable this test is; this means how well the investigators can obtain the same (or very&#xD;
      similar) results after multiple tests. The investigators would like to test this reliability&#xD;
      both between patients and the clinicians performing the testing.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Background Research:&#xD;
&#xD;
      The definition of an 'aneurysm' is permanent, localised dilatation of a blood vessel or heart&#xD;
      chamber. The abdominal aorta is the largest blood vessel in the human body and usually has a&#xD;
      diameter of 1.8 -2.0 centimetres (cm), dependant on age, sex and body habitus. Aortic&#xD;
      dilatation is generally classed as an 'aneurysm' when dilation of the vessel is 1.5 times the&#xD;
      normal size. An abdominal aortic aneurysm (AAA) affects any part of the aorta below the&#xD;
      diaphragm with 80 % typically being found between the renal artery and aortic bifurcation.&#xD;
&#xD;
      Risk Factors There are many factors that relate to the development of AAA. Gender is one of&#xD;
      the biggest non-modifiable risk factors, as an AAA is four to six times more likely in males&#xD;
      compared with females. Furthermore, the development of AAA in females occurs approximately&#xD;
      ten years later than males. The risk of AAA also increases if there is family history of the&#xD;
      disease, especially if the relative is first degree. There is also evidence to suggest there&#xD;
      is an association between AAA and coronary heart disease. Hypertension has also been found to&#xD;
      closely correlate with the development of AAA. Additionally, there is also a strong link&#xD;
      between smoking and the likelihood of AAA development. Conversely, whilst the risk of AAA&#xD;
      development in women is less than men, women have been shown to be more vulnerable to&#xD;
      developing AAA than their male counterparts. The risk of AAA's also increases after the age&#xD;
      of 65 years.&#xD;
&#xD;
      If AAA are left undetected or untreated there is an increase in the likelihood of a rupture&#xD;
      occurring. This causes critical internal bleeding and often results in death. Rupture of AAA&#xD;
      is the cause of approximately 6000 deaths per year in the United Kingdom. Figures between&#xD;
      1997- 2005 have shown a decrease in mortality but this is due to an earlier detection (of&#xD;
      around five to ten years). The likelihood of rupture increases due to age, sex, smoking,&#xD;
      hypertension and size and growth rate of the aneurysm. The size of the aneurysm is the&#xD;
      strongest predictor of risk of rupture, smoking also contributes to an acceleration in&#xD;
      expansion rate.&#xD;
&#xD;
      Ultrasound Screening:&#xD;
&#xD;
      Ultrasound screening is the preferred tool in identifying and monitoring the development of&#xD;
      AAA as it is highly sensitive, cost effective and a non-invasive tool. The National Institute&#xD;
      of Clinical Excellence (NICE) guidelines recommend that the National Health Service (NHS)&#xD;
      offers ultra-sonographic screening to all males age 65 or over. The ultrasound scan enables&#xD;
      the medical screener to determine the size of the abdominal aorta. According to the NICE&#xD;
      (1.3) guidelines AAA are categorised by size, with a diameter of less than three cm being&#xD;
      classified as normal with no follow up required. Patients who have an aneurysm diameter of&#xD;
      between 3- 4.4 cm are re-scanned yearly, with those between 4.5 -5.4 cm being rescanned&#xD;
      quarterly (every three months). AAA patients who have a diameter greater than 5.4 cm are&#xD;
      referred to a vascular consultant for diagnosis and treatment. An AAA can be either true or&#xD;
      false, with true aneurysms more commonly found. True aneurysms; involve three layers of the&#xD;
      blood vessel walls Intima, Media and Adventitia, whereas false aneurysms are essentially a&#xD;
      haematoma that forms outside the vessel wall.&#xD;
&#xD;
      Surgical management of AAA:&#xD;
&#xD;
      Following the diagnosis of a large AAA there are two possible medical surgical interventions,&#xD;
      open or endovascular repair (EVAR).Open repair is considered to be a major surgical procedure&#xD;
      and because of the possible complications preoperative assessment has to be carefully&#xD;
      managed. There are three approaches whilst performing AAA laparotomy, transverse incision,&#xD;
      longitude midline incision and retroperitoneal approach. The aortic segment is replaced by a&#xD;
      prosthetic graft. After the operation patients are often monitored in intensive care unit&#xD;
      (ICU) on average remain in hospital between seven to fourteen days. EVAR on the other hand is&#xD;
      less invasive procedure, less painful and has a shorter stay in hospital and often does not&#xD;
      require stay in ICU. EVAR gains access though the femoral artery and inserts a sent graft&#xD;
      inside the abdominal aneurysm.&#xD;
&#xD;
      Preoperative Risk Management:&#xD;
&#xD;
      Surgeons base the decisions for operating on two major factors, firstly the risk of rupture,&#xD;
      and secondly the diameter of the aneurysm and the growth rate. Before surgery the vascular&#xD;
      consultant will subject the patient to a preoperative functional capacity assessment (FCA).&#xD;
      The surgeons use FCA to establish if there are any potential operative and postoperative&#xD;
      risks. Patients often have other comorbidities so the risk of operating may outweigh the&#xD;
      potential benefits, therefore increasing the risk of premature mortality. The use of FCA has&#xD;
      become an important screening tool in evaluating the fitness of AAA patients, serving as a&#xD;
      good indictor to the risk of surgery and postoperative recovery. There are various ways to&#xD;
      test FCA (step test, spirometry and cardiopulmonary exercise testing etc.) however, more&#xD;
      recently cardiopulmonary exercise testing has been described as preferable tool in evaluating&#xD;
      AAA patient's functional capacity.&#xD;
&#xD;
      Cardio pulmonary exercise testing:&#xD;
&#xD;
      It is widely accepted that a cardio-pulmonary exercise test (CPEX) is the 'gold standard' of&#xD;
      FCA. Furthermore, CPEX is a non-invasive, cost effective and objective. It has been used for&#xD;
      many years in elite sporting performance for research and screening and is now becoming&#xD;
      increasingly utilised in clinical environments. CPEX testing allows clinicians to perform a&#xD;
      controlled exercise test in a safe environment. It involves the measurement of a number of&#xD;
      physiological parameters, as well as respiratory and cardiac monitoring.The basic underlying&#xD;
      physiological principles underlying a CPEX is that it measures the efficiency and capacity of&#xD;
      the oxygen-transport system; it also examines an individual's ability to exercise and the&#xD;
      cardiovascular responses to variable levels of exertion. A CPEX provides breath by breath&#xD;
      analysis and provides several important outcomes. These are; (1) VO2 MAX, (2) VeO2, (3)&#xD;
      VECO2, (4)anaerobic threshold (AT), (5) respiratory exchange ratio, (6) time to AT and (7)&#xD;
      total time tolerated are the variables that are obtained.&#xD;
&#xD;
      Anaerobic threshold (AT):&#xD;
&#xD;
      At the beginning of exercise, adenosine trisphosphate-creatine phosphate provides immediate&#xD;
      energy required by the working muscles. As exercise continues cardiac output increases&#xD;
      providing the working muscles with increased blood flow. As exercise levels rise, the&#xD;
      workload of the muscles also rises requiring more blood flow and oxygen to be delivered. The&#xD;
      oxygen demand is met by an increase cardiac output and lung ventilation. As the exercise&#xD;
      continuous to become more strenuous, the muscle demand will begin to exceed the rate of&#xD;
      oxygen delivery by the respiratory system. At this point the main fuel glucose is metabolised&#xD;
      into lactic acid. This dissociates to lactate and hydrogen ions (H+) resulting in acidosis,&#xD;
      which is the marker known as the Anaerobic Threshold (AT). The most common way of measuring&#xD;
      the AT non-invasively is the V-slope method see figure 1.&#xD;
&#xD;
      This can be explained via the following:&#xD;
&#xD;
      As a participant begins incremental exercise their expired minute volume (VE) increases&#xD;
      linearly with their oxygen consumption (VO2) and carbon dioxide consumption (VCO2). H+ are&#xD;
      produced via anaerobic metabolism which is buffered by bicarbonate (HCO3-) and produces&#xD;
      carbon dioxide (CO2). This is washed out in the lungs and is measured via the breath by&#xD;
      breath analysis in the expired air. As VCO2 rises disproportionately to VO2, it allows the&#xD;
      clinician to determine the AT; this is achieved by plotting VCO2 against VO2. Linear&#xD;
      regression lines are drawn through the upper and lower curve and the point of intersection&#xD;
      indicates where VCO2 increased disproportionately to VO2 and hence is estimated to be the AT.&#xD;
&#xD;
      An individual's aerobic capacity is known as their VO2MAX. The most common way of measuring a&#xD;
      person VO2 max is an incremental exercise test either performed on a motorized treadmill or&#xD;
      cycle-ergometer, measured in millilitres per kilogram per minute (ml.kg.min). The aerobic&#xD;
      capacity can be affected by factors such as gender, genetics, body composition and age. A&#xD;
      healthy 20-25 year old male has an average VO2 max of 42.5 - 46.4 ml.kg.min, whereas a&#xD;
      healthy female of the same age has an average of 33 - 36.9 ml.kg.min. There is approximately&#xD;
      ten percent drop with aerobic capacity every decade (dependent on fitness). For patients with&#xD;
      AAA it is suggested that they should achieve and a threshold (AT) value above 10.2 ml.kg.min&#xD;
      for open repair or above 8.2 for EVAR. They should also achieve a VO2MAX value above 15&#xD;
      ml.kg.min. Values lower than this can increase the risk of postoperative mortality (within 30&#xD;
      days).&#xD;
&#xD;
      Whilst there have been numerous studies into the importance of a CPEX, there have been no&#xD;
      studies to date which have determined the Inter and Intra reliability of this test in the AAA&#xD;
      population.&#xD;
&#xD;
      Aim:&#xD;
&#xD;
      The aim of this study is therefore to determine the Inter and Intra reliability of CPEX&#xD;
      testing on both a cycle- ergometer and motorised treadmill in patients with abdominal aortic&#xD;
      aneurysms.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">July 3, 2016</start_date>
  <completion_date type="Actual">June 14, 2017</completion_date>
  <primary_completion_date type="Actual">March 31, 2017</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <primary_purpose>Basic Science</primary_purpose>
    <masking>Single (Investigator)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Anaerobic threshold</measure>
    <time_frame>Up to One week</time_frame>
    <description>The anaerobic threshold is a physiological measurement which is generated via breath by breath analysis and determined by the v-slope method as described in the summary.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Minute ventilation</measure>
    <time_frame>Up to One week</time_frame>
    <description>Physiological measurement, computer generated via the breath by breath analysis</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Respiratory exchange ratio</measure>
    <time_frame>Up to One week</time_frame>
    <description>Physiological measurement, computer generated via the breath by breath analysis</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Total time of exercise</measure>
    <time_frame>Up to One week</time_frame>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Quality of life Questionnaire</measure>
    <time_frame>Up to One week</time_frame>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Time to anaerobic threshold</measure>
    <time_frame>Up to One week</time_frame>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Maximal oxygen uptake</measure>
    <time_frame>Up to One week</time_frame>
    <description>Physiological measurement, computer generated via the breath by breath analysis</description>
  </secondary_outcome>
  <number_of_arms>4</number_of_arms>
  <enrollment type="Actual">24</enrollment>
  <condition>Abdominal Aortic Aneurysm</condition>
  <arm_group>
    <arm_group_label>Treadmill-Test operator A</arm_group_label>
    <arm_group_type>Other</arm_group_type>
    <description>Randomised to motorised treadmill group A for inter reliability, observer A will perform both exercise tests</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Treadmill-Test operator B</arm_group_label>
    <arm_group_type>Other</arm_group_type>
    <description>Randomised to motorised treadmill group B for intra reliability, observer A will perform one exercise test, followed by observed B</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Cycle-Test operator A</arm_group_label>
    <arm_group_type>Other</arm_group_type>
    <description>Randomised to cycle group B for inter reliability, observer A will perform both exercise tests</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Cycle-Test operator B</arm_group_label>
    <arm_group_type>Other</arm_group_type>
    <description>Randomised to cycle group B for intra reliability, observer A will perform one exercise test, followed by observed B</description>
  </arm_group>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Observer</intervention_name>
    <description>Observer A and observer B</description>
    <arm_group_label>Cycle-Test operator A</arm_group_label>
    <arm_group_label>Cycle-Test operator B</arm_group_label>
    <arm_group_label>Treadmill-Test operator A</arm_group_label>
    <arm_group_label>Treadmill-Test operator B</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  • Must be over the age of 45&#xD;
&#xD;
               -  The patients must have the ability to walk unaided&#xD;
&#xD;
               -  Must be considered for open or endovascular repair&#xD;
&#xD;
               -  Have an AAA diameter of 5.4 cm or over.&#xD;
&#xD;
               -  English speaking and able to follow simple protocol instructions&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  • Active cancer treatment.&#xD;
&#xD;
               -  Patients whom are not able to give informed consent&#xD;
&#xD;
               -  Severe cardiovascular, musculo-skeletal or pulmonary illness precluding ability&#xD;
                  to partake in CPEX testing.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>45 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Amy E Harwood, MSc</last_name>
    <role>Principal Investigator</role>
    <affiliation>AVSU Hull Royal Infirmary</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Academic Vascular Surgery Unit, Vascular Laboratory, Alderson House, Hull Royal Infirmary</name>
      <address>
        <city>Hull</city>
        <state>East Riding Of Yorkshire</state>
        <zip>HU3 2JZ</zip>
        <country>United Kingdom</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>United Kingdom</country>
  </location_countries>
  <results_reference>
    <citation>Harwood AE, Pymer S, Hitchman L, Totty J, Wallace T, Smith GE, Carradice D, Carroll S, Chetter IC. The Intrarater and Interrater Reliability of Measures Derived from Cardiopulmonary Exercise Testing in Patients with Abdominal Aortic Aneurysms. Ann Vasc Surg. 2019 Apr;56:175-182. doi: 10.1016/j.avsg.2018.08.087. Epub 2018 Nov 23.</citation>
    <PMID>30476603</PMID>
  </results_reference>
  <verification_date>June 2019</verification_date>
  <study_first_submitted>October 19, 2016</study_first_submitted>
  <study_first_submitted_qc>November 21, 2016</study_first_submitted_qc>
  <study_first_posted type="Estimate">November 25, 2016</study_first_posted>
  <last_update_submitted>June 27, 2019</last_update_submitted>
  <last_update_submitted_qc>June 27, 2019</last_update_submitted_qc>
  <last_update_posted type="Actual">July 1, 2019</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Aneurysm</mesh_term>
    <mesh_term>Aortic Aneurysm</mesh_term>
    <mesh_term>Aortic Aneurysm, Abdominal</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
    <ipd_description>No plan to share participant data</ipd_description>
  </patient_data>
  <!-- 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/NCT02973308
org study id: 199037
nct id: NCT02973308
lead sponsor: 
collaborator: 
has dmc: No
Exercise testing is commonly being used in patients before surgery to test their overall
      fitness. One group it is being used in is patients who have an enlarged blood vessel in their
      stomach. This is known as an abdominal aortic aneurysm. The exercise test used is known as a
      cardiopulmonary exercise test as it looks at both heart and lung function at the same time.
      Whilst this test is commonly used there have been no studies (to date) which have looked at
      how reliable this test is; this means how well the investigators can obtain the same (or very
      similar) results after multiple tests. The investigators would like to test this reliability
      both between patients and the clinicians performing the testing.
Background Research:

      The definition of an 'aneurysm' is permanent, localised dilatation of a blood vessel or heart
      chamber. The abdominal aorta is the largest blood vessel in the human body and usually has a
      diameter of 1.8 -2.0 centimetres (cm), dependant on age, sex and body habitus. Aortic
      dilatation is generally classed as an 'aneurysm' when dilation of the vessel is 1.5 times the
      normal size. An abdominal aortic aneurysm (AAA) affects any part of the aorta below the
      diaphragm with 80 % typically being found between the renal artery and aortic bifurcation.

      Risk Factors There are many factors that relate to the development of AAA. Gender is one of
      the biggest non-modifiable risk factors, as an AAA is four to six times more likely in males
      compared with females. Furthermore, the development of AAA in females occurs approximately
      ten years later than males. The risk of AAA also increases if there is family history of the
      disease, especially if the relative is first degree. There is also evidence to suggest there
      is an association between AAA and coronary heart disease. Hypertension has also been found to
      closely correlate with the development of AAA. Additionally, there is also a strong link
      between smoking and the likelihood of AAA development. Conversely, whilst the risk of AAA
      development in women is less than men, women have been shown to be more vulnerable to
      developing AAA than their male counterparts. The risk of AAA's also increases after the age
      of 65 years.

      If AAA are left undetected or untreated there is an increase in the likelihood of a rupture
      occurring. This causes critical internal bleeding and often results in death. Rupture of AAA
      is the cause of approximately 6000 deaths per year in the United Kingdom. Figures between
      1997- 2005 have shown a decrease in mortality but this is due to an earlier detection (of
      around five to ten years). The likelihood of rupture increases due to age, sex, smoking,
      hypertension and size and growth rate of the aneurysm. The size of the aneurysm is the
      strongest predictor of risk of rupture, smoking also contributes to an acceleration in
      expansion rate.

      Ultrasound Screening:

      Ultrasound screening is the preferred tool in identifying and monitoring the development of
      AAA as it is highly sensitive, cost effective and a non-invasive tool. The National Institute
      of Clinical Excellence (NICE) guidelines recommend that the National Health Service (NHS)
      offers ultra-sonographic screening to all males age 65 or over. The ultrasound scan enables
      the medical screener to determine the size of the abdominal aorta. According to the NICE
      (1.3) guidelines AAA are categorised by size, with a diameter of less than three cm being
      classified as normal with no follow up required. Patients who have an aneurysm diameter of
      between 3- 4.4 cm are re-scanned yearly, with those between 4.5 -5.4 cm being rescanned
      quarterly (every three months). AAA patients who have a diameter greater than 5.4 cm are
      referred to a vascular consultant for diagnosis and treatment. An AAA can be either true or
      false, with true aneurysms more commonly found. True aneurysms; involve three layers of the
      blood vessel walls Intima, Media and Adventitia, whereas false aneurysms are essentially a
      haematoma that forms outside the vessel wall.

      Surgical management of AAA:

      Following the diagnosis of a large AAA there are two possible medical surgical interventions,
      open or endovascular repair (EVAR).Open repair is considered to be a major surgical procedure
      and because of the possible complications preoperative assessment has to be carefully
      managed. There are three approaches whilst performing AAA laparotomy, transverse incision,
      longitude midline incision and retroperitoneal approach. The aortic segment is replaced by a
      prosthetic graft. After the operation patients are often monitored in intensive care unit
      (ICU) on average remain in hospital between seven to fourteen days. EVAR on the other hand is
      less invasive procedure, less painful and has a shorter stay in hospital and often does not
      require stay in ICU. EVAR gains access though the femoral artery and inserts a sent graft
      inside the abdominal aneurysm.

      Preoperative Risk Management:

      Surgeons base the decisions for operating on two major factors, firstly the risk of rupture,
      and secondly the diameter of the aneurysm and the growth rate. Before surgery the vascular
      consultant will subject the patient to a preoperative functional capacity assessment (FCA).
      The surgeons use FCA to establish if there are any potential operative and postoperative
      risks. Patients often have other comorbidities so the risk of operating may outweigh the
      potential benefits, therefore increasing the risk of premature mortality. The use of FCA has
      become an important screening tool in evaluating the fitness of AAA patients, serving as a
      good indictor to the risk of surgery and postoperative recovery. There are various ways to
      test FCA (step test, spirometry and cardiopulmonary exercise testing etc.) however, more
      recently cardiopulmonary exercise testing has been described as preferable tool in evaluating
      AAA patient's functional capacity.

      Cardio pulmonary exercise testing:

      It is widely accepted that a cardio-pulmonary exercise test (CPEX) is the 'gold standard' of
      FCA. Furthermore, CPEX is a non-invasive, cost effective and objective. It has been used for
      many years in elite sporting performance for research and screening and is now becoming
      increasingly utilised in clinical environments. CPEX testing allows clinicians to perform a
      controlled exercise test in a safe environment. It involves the measurement of a number of
      physiological parameters, as well as respiratory and cardiac monitoring.The basic underlying
      physiological principles underlying a CPEX is that it measures the efficiency and capacity of
      the oxygen-transport system; it also examines an individual's ability to exercise and the
      cardiovascular responses to variable levels of exertion. A CPEX provides breath by breath
      analysis and provides several important outcomes. These are; (1) VO2 MAX, (2) VeO2, (3)
      VECO2, (4)anaerobic threshold (AT), (5) respiratory exchange ratio, (6) time to AT and (7)
      total time tolerated are the variables that are obtained.

      Anaerobic threshold (AT):

      At the beginning of exercise, adenosine trisphosphate-creatine phosphate provides immediate
      energy required by the working muscles. As exercise continues cardiac output increases
      providing the working muscles with increased blood flow. As exercise levels rise, the
      workload of the muscles also rises requiring more blood flow and oxygen to be delivered. The
      oxygen demand is met by an increase cardiac output and lung ventilation. As the exercise
      continuous to become more strenuous, the muscle demand will begin to exceed the rate of
      oxygen delivery by the respiratory system. At this point the main fuel glucose is metabolised
      into lactic acid. This dissociates to lactate and hydrogen ions (H+) resulting in acidosis,
      which is the marker known as the Anaerobic Threshold (AT). The most common way of measuring
      the AT non-invasively is the V-slope method see figure 1.

      This can be explained via the following:

      As a participant begins incremental exercise their expired minute volume (VE) increases
      linearly with their oxygen consumption (VO2) and carbon dioxide consumption (VCO2). H+ are
      produced via anaerobic metabolism which is buffered by bicarbonate (HCO3-) and produces
      carbon dioxide (CO2). This is washed out in the lungs and is measured via the breath by
      breath analysis in the expired air. As VCO2 rises disproportionately to VO2, it allows the
      clinician to determine the AT; this is achieved by plotting VCO2 against VO2. Linear
      regression lines are drawn through the upper and lower curve and the point of intersection
      indicates where VCO2 increased disproportionately to VO2 and hence is estimated to be the AT.

      An individual's aerobic capacity is known as their VO2MAX. The most common way of measuring a
      person VO2 max is an incremental exercise test either performed on a motorized treadmill or
      cycle-ergometer, measured in millilitres per kilogram per minute (ml.kg.min). The aerobic
      capacity can be affected by factors such as gender, genetics, body composition and age. A
      healthy 20-25 year old male has an average VO2 max of 42.5 - 46.4 ml.kg.min, whereas a
      healthy female of the same age has an average of 33 - 36.9 ml.kg.min. There is approximately
      ten percent drop with aerobic capacity every decade (dependent on fitness). For patients with
      AAA it is suggested that they should achieve and a threshold (AT) value above 10.2 ml.kg.min
      for open repair or above 8.2 for EVAR. They should also achieve a VO2MAX value above 15
      ml.kg.min. Values lower than this can increase the risk of postoperative mortality (within 30
      days).

      Whilst there have been numerous studies into the importance of a CPEX, there have been no
      studies to date which have determined the Inter and Intra reliability of this test in the AAA
      population.

      Aim:

      The aim of this study is therefore to determine the Inter and Intra reliability of CPEX
      testing on both a cycle- ergometer and motorised treadmill in patients with abdominal aortic
      aneurysms.
allocation: Randomized
intervention model: Parallel Assignment
primary purpose: Basic Science
masking: Single (Investigator)
measure: Anaerobic threshold
time frame: Up to One week
description: The anaerobic threshold is a physiological measurement which is generated via breath by breath analysis and determined by the v-slope method as described in the summary.
measure: Minute ventilation
time frame: Up to One week
description: Physiological measurement, computer generated via the breath by breath analysis
measure: Respiratory exchange ratio
time frame: Up to One week
description: Physiological measurement, computer generated via the breath by breath analysis
measure: Total time of exercise
time frame: Up to One week
measure: Quality of life Questionnaire
time frame: Up to One week
measure: Time to anaerobic threshold
time frame: Up to One week
measure: Maximal oxygen uptake
time frame: Up to One week
description: Physiological measurement, computer generated via the breath by breath analysis
arm group label: Treadmill-Test operator A
arm group type: Other
description: Randomised to motorised treadmill group A for inter reliability, observer A will perform both exercise tests
arm group label: Treadmill-Test operator B
arm group type: Other
description: Randomised to motorised treadmill group B for intra reliability, observer A will perform one exercise test, followed by observed B
arm group label: Cycle-Test operator A
arm group type: Other
description: Randomised to cycle group B for inter reliability, observer A will perform both exercise tests
arm group label: Cycle-Test operator B
arm group type: Other
description: Randomised to cycle group B for intra reliability, observer A will perform one exercise test, followed by observed B
intervention type: Other
intervention name: Observer
description: Observer A and observer B
arm group label: Cycle-Test operator A
arm group label: Cycle-Test operator B
arm group label: Treadmill-Test operator A
arm group label: Treadmill-Test operator B
criteria: 
gender: All
minimum age: 45 Years
maximum age: N/A
healthy volunteers: No
last name: Amy E Harwood, MSc
role: Principal Investigator
affiliation: AVSU Hull Royal Infirmary
facility: 
country: United Kingdom
citation: Harwood AE, Pymer S, Hitchman L, Totty J, Wallace T, Smith GE, Carradice D, Carroll S, Chetter IC. The Intrarater and Interrater Reliability of Measures Derived from Cardiopulmonary Exercise Testing in Patients with Abdominal Aortic Aneurysms. Ann Vasc Surg. 2019 Apr;56:175-182. doi: 10.1016/j.avsg.2018.08.087. Epub 2018 Nov 23.
PMID: 30476603
responsible party type: Sponsor
mesh term: Aneurysm
mesh term: Aortic Aneurysm
mesh term: Aortic Aneurysm, Abdominal
sharing ipd: No
ipd description: No plan to share participant data