Graft Failure and Consequences of Coronary Artery Bypass Graft Surgery

NCT06800430 | Recruiting

• 2 other identifiers: AC24158SS/CH/09/002
• Study Type: observational
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

Coronary artery bypass graft (CABG) surgery is the commonest type of heart operation performed. During this, arteries or veins (termed 'grafts') are used to supply blood around blockages within the blood vessels that supply the heart. Unfortunately, these grafts can sometimes fail, and patients can also experience complications like heart attacks and strokes, after surgery. It is known that vein grafts are more likely to narrow over time. Additionally, treating vein graft failure is very challenging, as repeat surgery is riskier and procedures to stent open the veins can also fail. However, it is not fully understood why these complications occur. In this study, the investigators will use an imaging technique called a total-body Positron Emission Tomography (PET) scan. This uses special radioactive dyes (radiotracers) to look at what is happening inside vein grafts. With this technique, the investigators will also be able to see what is happening to the heart, brain and wider parts of the body after CABG surgery. This study will aim to recruit 70 participants in total (maximum 150). 40 (maximum of 120) of these participants will have recently undergone CABG surgery and received ≥1 vein graft. The remaining 30 will have undergone CABG surgery ≥5 years ago and will have symptoms suggestive of vein graft failure. The study will last a total of 36 months and will involve participants undertaking the following assessments:

1. 1.Total-body Positron Emission Tomography and Computed Tomography (PET-CT) scan
2. 2.Ultrasound scan of the heart (echocardiogram)
3. 3.A blood test - up to four tablespoons (60 mL) of blood will be taken for immediate testing and the remainder will be stored for future ethically approved studies.

Conditions

Coronary Artery Bypass; Graft Failure; Coronary Artery Bypass Graft; Coronary Artery Bypass Graft Surgery (CABG)

Keywords

CABG; graft failure; coronary artery bypass; cardiovascular; heart surgery; cardiac surgery; coronary artery bypass graft; cardiovascular disease; heart disease; positron emission tomography

Outcome Measures

Primary Outcomes (3)

• Platelet activation

  The degree and location of platelet activation within saphenous vein grafts, measured using standard uptake values and tissue-to-background ratios of \[18F\]-GP1.

  3 years

• Fibroblast activation

  The degree and location of fibroblast activation within saphenous vein grafts, measured using standard uptake values and tissue-to-background ratios of \[68Ga\]-FAPI.

  3 years

• Macrophage activation

  The degree and location of macrophage activation within saphenous vein grafts, measured using standard uptake values and tissue-to-background ratios of \[68Ga\]-DOTATATE.

  3 years

Secondary Outcomes (1)

• Systemic cardiovascular disease

  3 years

Study Arms (2)

Cohort 1: Patients undergoing CABG surgery

40 patients (maximum 120) undergoing CABG surgery with multi-vessel disease and at least one saphenous vein graft.

Radiation: Hybrid [18F]-GP1, [68Ga]-DOTATATE, [68Ga]-FAPI total-body positron emission tomography and coronary computed tomography coronary angiography

Cohort 2: Patients with symptomatic saphenous vein graft vasculopathy

30 patients with prior CABG surgery (at least 5 years previously) with multi-vessel disease and two or more saphenous vein grafts, who have been referred for invasive coronary angiography due to symptoms and with a high suspicion of graft vasculopathy.

Radiation: Hybrid [18F]-GP1, [68Ga]-DOTATATE, [68Ga]-FAPI total-body positron emission tomography and coronary computed tomography coronary angiography

Interventions

Hybrid [18F]-GP1, [68Ga]-DOTATATE, [68Ga]-FAPI total-body positron emission tomography and coronary computed tomography coronary angiography RADIATION

Patients undergo hybrid \[18F\]-GP1, \[68Ga\]-FAPI and \[68Ga\]-DOTATATE total body PET-CT imaging (Biograph Vision Quadra, Siemens) and contrast-enhanced electrocardiogram gated CT coronary angiogram (CTCA), within 28 days (+/- 28 days) of their CABG surgery and again at 12 month follow-up.

Cohort 1: Patients undergoing CABG surgery

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

We will recruit two populations of patients following CABG surgery. Participants will be prospectively recruited following CABG surgery (cohort 1), or identification of clinically suspected saphenous vein graft failure (cohort 2). Recruitment will for both cohorts will be from a single, tertiary centre (Royal Infirmary of Edinburgh).

You may qualify if:

• Cohort 1: Patients undergoing CABG surgery
• Males and females over 18 years of age
• Patients undergoing CABG surgery for multivessel coronary artery disease, who receive at least one saphenous vein graft
• Cohort 2: Patients with symptomatic saphenous vein graft vasculopathy
• Males and females over 18 years of age
• Patients who underwent CABG surgery ≥ 5 years prior to recruitment for multivessel disease and received 2 or more saphenous vein grafts
• Referred for invasive coronary angiography due to recurrent symptoms and with a high suspicion of graft vasculopathy

You may not qualify if:

• Patients with a life expectancy of \< 2 years
• Renal failure (estimated glomerular filtration rate \<30 mL/min/1.73 m2)
• Patients on immunosuppressive therapies
• Females of child-bearing age who are pregnant or breastfeeding,
• Known allergy or contraindications to iodinated contrast or radiotracer
• Patients who are unable to tolerate the supine position
• Patients who are unable to provide informed consent

Sponsors & Collaborators

• University of Edinburgh: lead
• NHS Lothian: collaborator

Study Sites (1)

Royal Infirmary of Edinburgh

Edinburgh, Midlothian, EH16 4SA, United Kingdom

RECRUITING

Biospecimen

Retention: SAMPLES WITHOUT DNA

Venous blood samples (up to 60ml)

MeSH Terms

Conditions

Cardiovascular Diseases; Heart Diseases

Interventions

Ga(III)-DOTATOC

Central Study Contacts

Laura E Clark, BSc, MBChB, MRCS(Ed)

CONTACT

+447717478087; lclark15@ed.ac.uk

David E Newby, BSc (Hons) PhD BM DM DSc FRCP

CONTACT

d.e.newby@ed.ac.uk

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 22, 2025
• First Posted: January 30, 2025
• Study Start: March 28, 2025
• Primary Completion (Estimated): March 28, 2027
• Study Completion (Estimated): August 6, 2027
• Last Updated: April 20, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)