Validation of a Purine Biosensor in Detecting Acute Cerebral Ischaemia: Carotid Endarterectomy Model in SMARTChip (CEMS)

This study will validate the sensitivity of a purine biosensor (SMARTChip) in detecting acute cerebral ischaemia in a group of patients undergoing elective carotid endarterectomy. The study will also investigate whether blood purine levels are indicative of future risk of stroke by comparing pre-operative blood purine levels in carotid endarterectomy patients (high risk group) and blood purine levels in a group of age and sex-matched controls.

Study Overview

Status

Completed

Conditions

Detailed Description

Blood purine levels have been shown to be associated with ischaemic brain conditions. Studies have consistently shown that levels of purines in the blood rise rapidly when oxygen flow to the brain is reduced (hypoxia) and returns to the pre-hypoxic level within 30 minutes upon restoring the oxygen supply. There is therefore the potential for blood purine levels to be used to diagnose strokes more quickly. The investigators have undertaken a programme of work to develop, test and refine a purine biosensor, called SMARTChip. This is a prospective observational study to test the sensitivity of SMARTChip in detecting fluctuations in blood purine levels throughout various stages of carotid endarterectomy. Carotid endarterectomy patients have been chosen for this study because the procedure provides a controlled normoxic and hypoxic brain environment without compromising patient safety and has clear and systematic technical steps which will ensure reliable and robust data. The investigators will test the pre-, peri- and post-operative blood purine levels in 40 patients undergoing carotid endarterectomy at University Hospitals Coventry and Warwickshire NHS Trust, University Hospitals of North Midlands NHS Trust and University Hospitals Birmingham NHS Foundation Trust.

In this study the investigators will also test the hypothesis that purine levels may be predictive of future stroke risk. In a previous study carried out by the trial team patients undergoing carotid endarterectomy, a group that is by definition at increased risk of stroke, were found to have significantly higher purine levels than would be expected in a healthy population. Therefore a case-control study, including 80 patients recruited from the day surgery schedules at the three hospitals as controls and the 40 CEA patients recruited for the observational study as cases, will be undertaken alongside the observational study to assess whether purine levels differ systematically in CEA patients and controls.

Study Type

Observational

Enrollment (Actual)

198

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Staffordshire
      • Stoke-on-Trent, Staffordshire, United Kingdom, ST4 6QG
        • University Hospitals of North Midlands
    • West Midlands
      • Coventry, West Midlands, United Kingdom, CV2 2DX
        • University Hospitals Coventry and Warwickshire

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

40 male or female patients, aged 18 years or over, scheduled for carotid endarterectomy and 80 age and sex-matched control patients scheduled for day surgery. 50 dynamic controls. 25 Local sampling patients

Description

Inclusion Criteria:

CEA Patients:

  • Aged 18 years and over
  • Scheduled for carotid endarterectomy

Controls

  • Aged 18 years and over
  • Scheduled for day surgery

Dynamic controls

  • Aged 18 years and over
  • Scheduled for open aortic aneurysm repair, critical ischaemic leg surgery (this includes: Femoral endarterectomy, Axillo-Femoral Bypass Graft, Femoral distal bypass, Fem-Fem crossover graft, Axillary bifemoral graft, Aortobifemoral graft, and Femoral popliteal bypass), endovascular aneurysm repair, Kidney transplants, or Free flap surgery.

Local sampling

  • Aged 18 and over
  • Scheduled for elective lower limb vascular revascularisation, elective lower limb orthopaedic surgery with a tourniquet or diagnosed with acute compartment syndrome requiring a fasciotomy

Exclusion Criteria:

CEA patients:

- Unable/unwilling to provide informed consent

Controls:

  • Unable/unwilling to provide informed consent
  • History of cerebral ischaemia
  • History of cancer
  • History of cardiovascular disease
  • Unable/unwilling to provide a fasting blood sample

Dynamic controls

  • Unable/unwilling to provide informed consent
  • History of cerebral ischaemia
  • History of cancer (except for Free flap surgery patients)

Local sampling

  • Unable/unwilling to provide informed consent
  • History of cerebral ischaemia
  • History of cancer
  • History of cardiovascular disease
  • Unable/unwilling to provide a blood sample

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Carotid endarterectomy patients
40 male and female patients, aged 18 years and over, scheduled for carotid endarterectomy. Fasted pre-operative (arterial and capillary), peri-operative (arterial) and 1-hour and 24-hour post-operative (arterial) blood samples will be collected and analysed for serum purine concentration.
Control patients
80 age and sex-matched control patients scheduled for non-vascular, non-oncological day surgery. A single pre-operative fasted capillary (finger-prick) blood sample will be collected and analysed for serum purine concentration.
Dynamic controls
10 aortic aneurysm repair patients, 10 critical leg ischaemia patients, 10 endovascular aneurysm repair patients, 10 kidney transplant patients, and 10 free flap surgery patients.
Local sampling patients
10 Patients undergoing revascularisation, 10 patients undergoing lower limb surgery with a tourniquet and 5 patients diagnosed with acute compartment syndrome.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pre-, peri-, and post-operative arterial serum purine concentration (uM)
Time Frame: 24 hours
Change in arterial serum purine concentration measured pre-, peri-, and post-operatively in CEA patients
24 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pre-, and post-operative arterial serum purine concentration (uM)
Time Frame: Baseline
Arterial serum purine concentration measured pre-operatively in CEA patients, controls and local sampling patients.
Baseline
Pre-, and post-operative capillary serum purine concentration (uM)
Time Frame: Baseline
Pre-operative capillary serum purine concentration in CEA patients, controls and local sampling patients.
Baseline
Local or general anaesthetic
Time Frame: Baseline
Local or general anaesthetic used during procedure in CEA patients, controls and local sampling patients.
Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Collaborators

Investigators

  • Study Chair: Christopher HE Imray, MB BS PhD, University Hospitals Coventry and Warwickshire NHS Trust
  • Principal Investigator: Jack Fairhead, BM BCh BA, University Hospitals of North Midlands NHS Trust

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 16, 2016

Primary Completion (Actual)

May 20, 2022

Study Completion (Actual)

May 20, 2022

Study Registration Dates

First Submitted

September 7, 2015

First Submitted That Met QC Criteria

September 7, 2015

First Posted (Estimate)

September 9, 2015

Study Record Updates

Last Update Posted (Actual)

July 12, 2022

Last Update Submitted That Met QC Criteria

July 11, 2022

Last Verified

July 1, 2022

More Information

Terms related to this study

Other Study ID Numbers

  • CI163115

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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