Peripheral Arterial DiseaseKIDNCT07891988
Preventing Kidney Injury Using Carbon Dioxide as Contrast Medium in Patients With Peripheral Arterial Disease (PAD) and Chronic Kidney Disease (CKD) Having Arterial Intervention
A study testing Iodinated contrast medium and CO2 automated injector contrast medium in people with Peripheral Arterial Disease and Chronic Kidney Diseases, run by University of Leicester at 6 sites in United Kingdom.
Trial summary
This research trial will test whether using carbon dioxide as a contrast medium during surgery to open blocked leg arteries can prevent kidney injury. One in five people over 55 in the UK suffer with narrowing or blockages in their leg arteries, which is called peripheral arterial disease. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Peripheral Arterial Disease, Chronic Kidney Diseases, Acute Kidney Injury
- What is being tested?
- Iodinated contrast medium and CO2 automated injector contrast medium
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 184 participants
- Where
- 6 sitesUnited Kingdom
- Study dates
- 13 Feb 2025to 30 Oct 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age > 18 years
- Undergoing any revascularisation with an endovascular component
- Estimated glomerular filtration rate <60ml/min/1.73m2 (two separate eGFR readings <60 ml/min/1.73m² in the last three months) .
- Signed informed consent
Who cannot join
- Known allergy to iodinated contrast media
- Individuals already on long-term dialysis at time of screening
- An inability to understand the languages in which the trial materials are provided.
Trial locations and contacts
6 sites in 1 country.
6 sites in 1 country
United Kingdom6 sites
Hull University Hospitals Teaching NHS Trust
Hull, HU3 2JZ
University Hospital of Leicester NHS Trust
Leicester, Leicestershire, LE3 9QP
Guy's and St Thomas' NHS Foundation Trust
London, SE1 7EH
St George's University Hospitals NHS Foundation Trust
London, SW17 0RE
Manchester University NHS Foundation Trust
Manchester, M13 9WL
University Hospitals of North Midlands NHS Trust
Stoke-on-Trent, ST4 6QG
About this study
This research trial will test whether using carbon dioxide as a contrast medium during surgery to open blocked leg arteries can prevent kidney injury. One in five people over 55 in the UK suffer with narrowing or blockages in their leg arteries, which is called peripheral arterial disease. It leads to poor leg circulation, which can cause leg gangrene or infection. Sometimes this may even lead to major lower limb amputation. To prevent this from happening, the affected arteries can be opened using endovascular revascularisation. These procedures are the most common artery surgeries in the NHS. To be able to perform these procedures, doctors use an iodine-based contrast medium (dye) injected in the artery, which can negatively affect kidney function.
Instead of the usual dye that causes kidney problems, carbon dioxide can be used as it does not damage the kidneys. No previous randomised controlled trial, however, has tested whether using carbon dioxide via automated injectors does indeed protect the kidneys in these procedures.
This research will take place in at least six NHS hospitals in the UK. People with peripheral arterial disease and chronic kidney disease who are having a procedure to open their arteries will be asked to take part. Participants will be randomly chosen to have the procedure with carbon dioxide or with standard iodine-based contrast medium. The investigators will then perform blood tests to measure serum creatinine on the 2nd, 30th, and 90th day after the procedure to compare kidney function between the two groups. The investigators will also compare the volume of iodine-based contrast medium used. The study will also include qualitative research into how the hospital staff performing the intervention feel, as well as how participants found the procedure with carbon dioxide.
Read the detailed description
Background and Rationale Peripheral arterial disease (PAD) frequently coexists with chronic kidney disease (CKD). Endovascular revascularisation, a common procedure for PAD, typically relies on iodine-based contrast medium, which is nephrotoxic and a known contributor to acute kidney injury (AKI). Patients developing AKI post-revascularisation face increased long-term major cardiovascular events, progression of CKD, and mortality. Using carbon dioxide (CO2) as an alternative contrast medium may mitigate this risk, as CO2 is not nephrotoxic. Automated intra-arterial CO2 injectors have recently been developed to address previous technical constraints associated with CO2 delivery, such as procedural pain and suboptimal imaging.
Trial Design and Methodology This research is a multicentre, prospective, open-label, parallel-group randomised controlled trial. The trial takes place across at least six UK NHS hospitals providing specialist care for PAD. Following informed consent, participants are randomised via a centralised web-based system in a 1:1 ratio within 15 days of consent. Randomisation is minimised by baseline CKD stage, age, presence of tissue loss, and diabetes. The study intends to recruit 174 participants to achieve 90% power to detect a clinically meaningful difference in serum creatinine values, accounting for a 10% participant drop-out rate.
Procedural Details All pre- and post-procedure care remains identical for both the intervention and control groups, adhering to existing NHS PAD care pathways and National Institute of Health and Care Excellence (NICE) guidance, which includes standard oral and intravenous fluid therapy. The investigators will monitor renal function by recording serum creatinine levels at baseline and at 2, 30, and 90 days post-procedure. Follow-up assessments will take place either in-person at the vascular clinic or via telephone until day 90.
Qualitative and Health Economic Evaluations The trial incorporates a health economic evaluation to assess the cost-effectiveness of the automated CO2 injector from an NHS and societal perspective. This evaluation utilises intraprocedural data, healthcare resource usage data, and Quality of Life (QoL) assessments collected via validated questionnaires at 90 days post-procedure.
Additionally, a qualitative and implementation sub-study will be conducted to explore acceptability and implementation factors. A purposively selected subgroup of up to 12 participants receiving the CO2 automated injector, alongside up to 20 involved healthcare practitioners, will complete semi-structured interviews guided by the Theoretical Framework of Acceptability (TFA). Bespoke questionnaires will also be administered to practitioners to evaluate the feasibility, appropriateness, and innovation-specific implementation intentions associated with the technology.
- Being tested
- Iodinated contrast medium, CO2 automated injector contrast medium
- Keywords
- Nephrotoxic, Endovascular, Revascularisation, Acute kidney injury, Iodine-based contrast medium, Carbon dioxide, Peripheral arterial disease
- Medical subject headings
- Peripheral Arterial Disease, Renal Insufficiency, Chronic, Acute Kidney Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Iodinated contrast mediumOther
Standard of care iodinated contrast medium used by NHS trusts across the UK for endovascular revascularisation.
CO2 automated injector contrast mediumOther
Also called Angiodroid
Carbon dioxide via an automated injector contrast medium
| Study group | Role | What they receive |
|---|---|---|
| Iodine contrast medium | Active comparator | Standard of care Receives: Other: Iodinated contrast medium |
| CO2 automated injector contrast medium | Experimental | CO2 automated injector Receives: Other: CO2 automated injector contrast medium |
What is being measured
The primary outcome is the main question the study is designed to answer.
Renal Function: Log Serum Creatinine
Assessment of short and medium-term renal decline by measuring serum creatinine from blood samples processed at local pathology laboratories. Unit of Measure: log(µmol/L). Renal decline or "worsening of kidney function" is defined as a >25% decline in the estimated Glomerular Filtration Rate (eGFR) from the baseline assessment. The baseline eGFR is defined as the most recent value recorded prior to the procedure. Additionally, the trial measures short and medium-term renal decline by tracking changes in Log serum creatinine at 2, 30, and 90 days post-procedure, and evaluates the onset of Acute Kidney Injury (AKI) based on the KDIGO criteria.
Measured: 2, 30, and 90 days after endovascular revascularisation
Secondary outcomes (11)
Volume of iodinated contrast medium used
Measurement of the overall volume of iodinated contrast medium required to complete the endovascular revascularisation procedure. Unit of Measure: Milliliters (ml)
Measured: Intraoperative (during the index procedure)
Incidence of Acute Kidney Injury (AKI)
Assessment of the development of acute kidney injury evaluated using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Unit of Measure: Percentage (%) of participants
Measured: Within 2 days (48 hours) of the procedure
Proportion of participants developing Major Adverse Kidney Events (MAKE)
The development of a major adverse kidney event, defined as either death, new requirement for dialysis, or worsening kidney function indicated by a >25% decline in estimated Glomerular Filtration Rate (eGFR) from baseline. Unit of Measure: Percentage (%) of participants
Measured: By 90 day post index procedure follow-up
Inpatient stay duration
The length of time the participant spent as an inpatient since randomisation. Unit of Measure: Days
Measured: By 90 day post index procedure follow-up
Pain experienced during the procedure
Assessment of the pain experienced by the participant during the injection of the contrast medium, measured using a Visual Analogue Scale (VAS). The scale ranges from 0 to 10, where 0 indicates no pain and 10 indicates the worst possible pain. Unit of Measure: Score on a scale from 0 to 10
Measured: During the index procedure (measured at the first and final angiogram)
Quality of Life: EQ-5D-5L
Assessment of health-related quality of life measured using the EuroQOL 5D 5L (EQ-5D-5L) Questionnaire. It assesses 5 dimensions on a 1-5 scale and includes a visual analogue scale rating current health from 0 (worst) to 100 (best). Unit of Measure: Score on a scale from 0 to 100
Measured: Baseline and 90 days post-procedure
Quality of Life: SF-36
Assessment of health-related quality of life measured using the 36-Item Short Form Health Survey (SF-36) Questionnaire, which covers eight domains of health converted into a total score indicating low to high quality of life. Unit of Measure: Total score
Measured: Time Frame: Baseline and 90 days post-procedure
Planned Revascularisation Completion Rate
Evaluation of the technical success of the intervention by calculating the proportion of endovascular revascularisation procedures that were completed as originally planned. Unit of Measure: Percentage (%) of participants
Measured: Intraoperative (during the index procedure)
Number of Re-interventions
Tracking the total number of subsequent surgical or endovascular re-interventions required. Unit of Measure: Number of interventions
Measured: By 90 day post index procedure follow-up
Participant Intervention Acceptability
Evaluation of the acceptability of receiving carbon dioxide via the automated injector, assessed using a self-reported 8-item Theoretical Framework of Acceptability (TFA) Questionnaire. Higher scores indicate a higher level of acceptability. Unit of Measure: Score from 8 to 40
Measured: By 90 day post index procedure follow-up
Procedure Associated Costs
A micro-costing health economic analysis calculating the costs associated with the procedure, including equipment, staff, hospital stays, and community services. Cost in Great British Pounds (£)
Measured: By 90 day post index procedure follow-up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Oct 2026
- Study start13 Feb 2025
- Primary completion12 Oct 2026
- Study completion30 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Peripheral Arterial DiseaseStudies of the same condition, open and under way.
- 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 184 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Leicester
- Sponsor type
- University, hospital or other
- Collaborators
- St George's, University of London, University of Nottingham, King's College London, The Leeds Teaching Hospitals NHS Trust
- Responsible party
- Sponsor
- Investigators
- Athanasios Saratzis, Principal investigator, NIHR Leicester Biomedical Research Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07891988
- Sponsor's protocol ID
- 0980
- Acronym
- KID
- Status last verified
- Oct 2026
- First submitted
- 10 Jul 2024
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Preventing Kidney Injury Using Carbon Dioxide as Contrast Medium in Patients With Peripheral Arterial Disease (PAD) and Chronic Kidney Disease (CKD) Having Arterial Intervention
- ClinicalTrials.gov ID
- NCT07891988
- Acronym / sponsor ID
- KID / 0980
- Keywords
- Nephrotoxic, Endovascular, Revascularisation, Acute kidney injury, Iodine-based contrast medium, Carbon dioxide, Peripheral arterial disease
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 184 participants (actual)
- Lead sponsor
- University of LeicesterUniversity, hospital or other
- Collaborators
- St George's, University of London, University of Nottingham, King's College London, The Leeds Teaching Hospitals NHS Trust
- Study start
- 13 Feb 2025 (actual)
- Primary completion
- 12 Oct 2026 (actual)
- Study completion
- 30 Oct 2026 (estimated)
- First posted
- 23 Oct 2026 (actual)
- 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.
This research trial will test whether using carbon dioxide as a contrast medium during surgery to open blocked leg arteries can prevent kidney injury. One in five people over 55 in the UK suffer with narrowing or blockages in their leg arteries, which is called peripheral arterial disease. It leads to poor leg circulation, which can cause leg gangrene or infection. Sometimes this may even lead to major lower limb amputation. To prevent this from happening, the affected arteries can be opened using endovascular revascularisation. These procedures are the most common artery surgeries in the NHS. To be able to perform these procedures, doctors use an iodine-based contrast medium (dye) injected in the artery, which can negatively affect kidney function.
Instead of the usual dye that causes kidney problems, carbon dioxide can be used as it does not damage the kidneys. No previous randomised controlled trial, however, has tested whether using carbon dioxide via automated injectors does indeed protect the kidneys in these procedures.
This research will take place in at least six NHS hospitals in the UK. People with peripheral arterial disease and chronic kidney disease who are having a procedure to open their arteries will be asked to take part. Participants will be randomly chosen to have the procedure with carbon dioxide or with standard iodine-based contrast medium. The investigators will then perform blood tests to measure serum creatinine on the 2nd, 30th, and 90th day after the procedure to compare kidney function between the two groups. The investigators will also compare the volume of iodine-based contrast medium used. The study will also include qualitative research into how the hospital staff performing the intervention feel, as well as how participants found the procedure with carbon dioxide.
Detailed description
Background and Rationale Peripheral arterial disease (PAD) frequently coexists with chronic kidney disease (CKD). Endovascular revascularisation, a common procedure for PAD, typically relies on iodine-based contrast medium, which is nephrotoxic and a known contributor to acute kidney injury (AKI). Patients developing AKI post-revascularisation face increased long-term major cardiovascular events, progression of CKD, and mortality. Using carbon dioxide (CO2) as an alternative contrast medium may mitigate this risk, as CO2 is not nephrotoxic. Automated intra-arterial CO2 injectors have recently been developed to address previous technical constraints associated with CO2 delivery, such as procedural pain and suboptimal imaging.
Trial Design and Methodology This research is a multicentre, prospective, open-label, parallel-group randomised controlled trial. The trial takes place across at least six UK NHS hospitals providing specialist care for PAD. Following informed consent, participants are randomised via a centralised web-based system in a 1:1 ratio within 15 days of consent. Randomisation is minimised by baseline CKD stage, age, presence of tissue loss, and diabetes. The study intends to recruit 174 participants to achieve 90% power to detect a clinically meaningful difference in serum creatinine values, accounting for a 10% participant drop-out rate.
Procedural Details All pre- and post-procedure care remains identical for both the intervention and control groups, adhering to existing NHS PAD care pathways and National Institute of Health and Care Excellence (NICE) guidance, which includes standard oral and intravenous fluid therapy. The investigators will monitor renal function by recording serum creatinine levels at baseline and at 2, 30, and 90 days post-procedure. Follow-up assessments will take place either in-person at the vascular clinic or via telephone until day 90.
Qualitative and Health Economic Evaluations The trial incorporates a health economic evaluation to assess the cost-effectiveness of the automated CO2 injector from an NHS and societal perspective. This evaluation utilises intraprocedural data, healthcare resource usage data, and Quality of Life (QoL) assessments collected via validated questionnaires at 90 days post-procedure.
Additionally, a qualitative and implementation sub-study will be conducted to explore acceptability and implementation factors. A purposively selected subgroup of up to 12 participants receiving the CO2 automated injector, alongside up to 20 involved healthcare practitioners, will complete semi-structured interviews guided by the Theoretical Framework of Acceptability (TFA). Bespoke questionnaires will also be administered to practitioners to evaluate the feasibility, appropriateness, and innovation-specific implementation intentions associated with the technology.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Iodine contrast medium | Active comparator | Other: Iodinated contrast mediumStandard of care |
| CO2 automated injector contrast medium | Experimental | Other: CO2 automated injector contrast mediumCO2 automated injector |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age > 18 years
- Undergoing any revascularisation with an endovascular component
- Estimated glomerular filtration rate <60ml/min/1.73m2 (two separate eGFR readings <60 ml/min/1.73m² in the last three months) .
- Signed informed consent
Key exclusion criteria (3 listed)
- Known allergy to iodinated contrast media
- Individuals already on long-term dialysis at time of screening
- An inability to understand the languages in which the trial materials are provided.
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 |
|---|---|---|
| Iodinated contrast mediumStandard of care iodinated contrast medium used by NHS trusts across the UK for endovascular revascularisation. | Other | Iodine contrast medium |
| CO2 automated injector contrast mediumAlso: AngiodroidCarbon dioxide via an automated injector contrast medium | Other | CO2 automated injector contrast medium |
Primary outcome
Renal Function: Log Serum Creatinine
Time frame: 2, 30, and 90 days after endovascular revascularisation
Assessment of short and medium-term renal decline by measuring serum creatinine from blood samples processed at local pathology laboratories. Unit of Measure: log(µmol/L). Renal decline or "worsening of kidney function" is defined as a >25% decline in the estimated Glomerular Filtration Rate (eGFR) from the baseline assessment. The baseline eGFR is defined as the most recent value recorded prior to the procedure. Additionally, the trial measures short and medium-term renal decline by tracking changes in Log serum creatinine at 2, 30, and 90 days post-procedure, and evaluates the onset of Acute Kidney Injury (AKI) based on the KDIGO criteria.
11 secondary outcomes
Volume of iodinated contrast medium used
Time frame: Intraoperative (during the index procedure)
Incidence of Acute Kidney Injury (AKI)
Time frame: Within 2 days (48 hours) of the procedure
Proportion of participants developing Major Adverse Kidney Events (MAKE)
Time frame: By 90 day post index procedure follow-up
Inpatient stay duration
Time frame: By 90 day post index procedure follow-up
Pain experienced during the procedure
Time frame: During the index procedure (measured at the first and final angiogram)
Quality of Life: EQ-5D-5L
Time frame: Baseline and 90 days post-procedure
Quality of Life: SF-36
Time frame: Time Frame: Baseline and 90 days post-procedure
Planned Revascularisation Completion Rate
Time frame: Intraoperative (during the index procedure)
Number of Re-interventions
Time frame: By 90 day post index procedure follow-up
Participant Intervention Acceptability
Time frame: By 90 day post index procedure follow-up
Procedure Associated Costs
Time frame: By 90 day post index procedure follow-up
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2026.
- Individual participant dataSharing planned: No
Related trials for Peripheral Arterial Disease
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The THOR IDE Study
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Truway Diagnostic Tools in Primary Care
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RecruitingPhase 3
Reducing Adverse Vascular Outcomes With Factor XI Inhibition in Adult Participants With Peripheral Artery Disease
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Active, not recruiting
Thromboelastography With Platelet Mapping to Guide Antiplatelet Therapy After Lower Extremity Revascularization
Thrombosis, Arterial Occlusive Diseases
Not yet recruiting
Daily Stretching to Improve Walking in Older Patients With Peripheral Artery Disease: The STRETCH PAD Study
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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.
Athanasios Saratzis principal investigator
NIHR Leicester Biomedical Research Centre
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Iodinated contrast medium and CO2 automated injector contrast medium in people with Peripheral Arterial Disease and Chronic Kidney Diseases, run by University of Leicester at 6 sites in United Kingdom.
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 4 inclusion and 3 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: under way, not looking for participants, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in United Kingdom. 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?
This study is still under way. Results are not available in the source record yet.
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?
Renal Function: Log Serum Creatinine (time frame: 2, 30, and 90 days after endovascular revascularisation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Oct 2026.