PET CT analysis of restenosis after lower limb revascularisation

ISRCTN ISRCTN34690731
DOI https://doi.org/10.1186/ISRCTN34690731
IRAS number 167667
Secondary identifying numbers IRAS: 167667
Submission date
12/06/2017
Registration date
15/08/2017
Last edited
08/04/2020
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims:
Peripheral arterial disease (PAD) is a common condition in which the blood flow to the legs is restricted. This happens because of the buildup of a fatty substance (plaque) on the walls of arteries. Over time this can cause the main arteries in the legs to become narrowed (stenosed) or blocked (occluded). As the arteries become narrower, patients begin the feel pain even when at rest and are at severe risk of developing ulcers or gangrene (acute lower limb ischaemia), which in severe cases can lead to amputation. For many patients, the only viable treatment option is to undergo surgery to restore blood flow. This is usually done using a procedure called an angioplasty (where a special balloon is inflated inside the affected artery to widen it) or an operation to bypass the blocked portion of the artery in the leg using a piece of another blood vessel. In some cases, arteries can become narrowed again after surgery (restenosis) however. A key challenge for blood vessel imaging is being able to predict restenosis in order to better understand the underlying biology and to allow tracking of the initial plaque's response to therapy. Work undertaken in Cambridge has shown that a type of imaging called positron emission tomography/computed tomography (PET/CT), which uses injectable radioactive dye, could be more accurate at tracking and monitoring plaques than standard techniques (involving ultrasound scans of blood vessels). The aim of this study is to look at examine the role of arterial inflammation and calcification both before and after a superficial femoral artery angioplasty.

Who can participate?
Men aged over 50 and women aged over 55 who are undergoing surgical treatment for PAD.

What does the study involve?
Participants who have an angioplasty scheduled are asked to attend the hospital twice prior to their surgery for scans. At each session, participants have their legs scanned with a PET/CT machine. They are given a small amount of tracer, inserted through a cannula (thing plastic tube) inserted into a vein. Participants also undergo a scan at the first session using an ultrasound (a scan that uses sound waves) to look at the blood flow of their legs. Participants then undergo their surgery. Six weeks after the surgery, the PET/CT scan is repeated. At 12 months after surgery, they undergo a final ultrasound scan.

What are the possible benefits and risks of participating?
There are no direct benefits with participating. There is a small risk of exposure to radiation due to the scans. There is a small and unlikely risks of allergic reaction or other side effects however the hospital has facilities to deal with this. Participant may experience discomfort when the cannula is placed into a vein, as well as bruising.

Where is the study run from?
Addenbrooke's Hospital (UK)

When is study starting and how long is it expected to run for?
November 2015 to October 2018

Who is funding the study?
British Heart Foundation (UK)

Who is the main contact?
Dr Mohammed Chowdhury

Contact information

Dr Mohammed Chowdhury
Public

Box 212
Vascular Surgery
Addenbrooke's Hospital
Hills Road
Cambridge
CB2 0QQ
United Kingdom

ORCiD logoORCID ID 0000-0003-0384-7197

Study information

Study designObservational cohort study
Primary study designObservational
Secondary study designCohort study
Study setting(s)Hospital
Study typeOther
Participant information sheet ISRCTN34690731_PIS_26Aug15_V3.docx
Scientific titleMulti-modality imaging to determine the role of calcification and inflammation on restenosis rates following lower limb angioplasty: The CIRLA Study
Study acronymCIRLA
Study objectivesHypothesis:
Increased level of arterial wall inflammation and calcification predict restenosis risk following angioplasty of the superficial femoral artery.

Study aim:
The general aim of this project is to determine the role of arterial inflammation and calcification both pre- and post-intervention in risk of restenosis following superficial femoral artery angioplasty.
Ethics approval(s)East of England - Cambridge East Research Ethics Committee, 10/09/2015, ref: 15/EE/0153
Health condition(s) or problem(s) studiedPeripheral Arterial Disease
InterventionPatients are identified from vascular clinic or vascular inpatient wards. As part of their usual clinical stream, participants are assessed and, if it is deemed appropriate, are scheduled to have a SFA angioplasty which is then booked.

Participants are then reviewed prior to this intervention and assessed for inclusion into the study (see inclusion/exclusion criteria). Eligible participants are approached and provided written information about the study. Participants are invited to the hospital on two separate days for a scanning session prior to the planned angioplasty. At each session the patient's legs will be scanned on a combined PET/CT machine. The scans will involve administration of a radioactive tracer. A cannula (thin plastic tube) will be inserted into the patient. The tracer will be injected through the cannula and the scans would be done 2 hours after the injection of the tracer. The technique is so sensitive that only a very tiny amount of the radioactive tracer is required. During the scan, patients are asked to lie flat on a bed on their back within the CT machine (which is shaped like a large doughnut). On the first of these days, patientsalso undergo an ultrasound scan of both legs to look at the blood flow through the arteries. Participants undergo their SFA angioplasty done to the standard level of care.

Six weeks after the angioplasty, participants return for their repeat PET-CT scans and are followed-up for 12 months thereafter. If participants undergo stenting at the time of angioplasty they are not invited back for the repeat PET-CT scan. At 12-months post angioplasty each participant have a final ultrasound duplex scan on completing the study.
Intervention typeDevice
Pharmaceutical study type(s)
Phase
Drug / device / biological / vaccine name(s)
Primary outcome measure1. Primary patency, defined as SFA stenosis/anastamotic stenosis of < 50%, is measured using arterial duplex scanning at 12 months
2. FDG and NaF TBR measurements are measured using the scans at baseline and six weeks
3. Ankle-brachial pressure index bilaterally is measured using scanning at baseline
4. Blood markers and degree of disease are assessed using ultrasound duplex at baseline
5. Restenosis is measured using the ultrasound duplex at 12 months
Secondary outcome measuresFreedom from target lesion revascularization (TLR) at 1 year is measured by arterial duplex at 12 months.
Overall study start date01/10/2015
Completion date01/10/2018

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants50
Total final enrolment50
Key inclusion criteria1. Aged 50 years or over (women aged 55 years or over)
2. Symptomatic peripheral arterial disease (intermittent claudication / critical limb ischaemia)
3. Undergoing superficial femoral artery angioplasty (PTA) or femoro-popliteal vein bypass graft (FPBG)
4. Patients with TASC A and B lesions for the PTA group (there will be no restriction with regard to disease severity on the FPBG group as long as the anastomosis is to the popliteal artery)
5. Taking standard antiplatelet/statin medication
Key exclusion criteria1. Inability to undergo PET/CT
2. Presence of end stage renal failure
3. Metastatic malignancy
4. Patients undergoing adjunct endovascular procedures in the infrainguinal segments – PTA group only (e.g. Bare Metal Stent, Drug Eluting Balloon, Drug Eluting Stent)
5. Previous ipsilateral femoral artery angioplasty within the previous 6 months – PTA group only
6. Women under the age of 55 years
7. Patients with diabetes mellitus taking insulin
Date of first enrolment01/11/2015
Date of final enrolment01/07/2017

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Addenbrooke's Hospital
Cambridge University Hospital Trust
Hills Road
Cambridge
CB2 0QQ
United Kingdom

Sponsor information

British Heart Foundation
Research organisation

Lyndon Place
2096 Coventry Road
Sheldon
Birmingham
B26 3YU
United Kingdom

Phone +44 300 330 3322
Email supporterservices@bhf.org.uk
Website https://www.bhf.org.uk
ROR logo "ROR" https://ror.org/02wdwnk04

Funders

Funder type

Charity

British Heart Foundation
Private sector organisation / Trusts, charities, foundations (both public and private)
Alternative name(s)
the_bhf, The British Heart Foundation, BHF
Location
United Kingdom

Results and Publications

Intention to publish date31/12/2018
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planPlanned presentation at major cardiovascular meetings in the UK and USA, and publication in a major, high-impact, peer-reviewed cardiovascular journal.
IPD sharing planThe datasets generated during and/or analysed during the current study are/will be available upon request from Mr Mohammed Chowdhury (mmc59@cam.ac.uk)

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Participant information sheet version V3 26/08/2015 15/08/2017 No Yes
Results article results 01/04/2020 08/04/2020 Yes No
HRA research summary 28/06/2023 No No

Additional files

ISRCTN34690731_PIS_26Aug15_V3.docx
Uploaded 15/08/2017

Editorial Notes

08/04/2020: The following changes have been made:
1. Publication reference added.
2. The final enrolment number has been added from the reference.