CTCA Prior to Invasive Angiography in Post-Bypass Patients (BYPASS CTCA 2)

A Multi-Centre, Randomised Trial Assessing the Value of Computed Tomography Coronary Angiography Prior to Invasive Coronary Angiography in Patients With Previous Coronary Artery Bypass Grafts in Reducing Cardiac Events

The goal of this clinical trial is to evaluate whether a coronary computed tomography angiography (CTCA)-guided strategy can reduce the risk of death, heart attack, stroke, and hospital admissions in patients experiencing angina or myocardial infarction following coronary artery bypass graft (CABG) surgery. The main questions it aims to answer are:

• Can CTCA reduce major adverse cardiovascular events compared to standard invasive coronary angiography?
• Is CTCA a cost-effective and safer alternative that improves patient quality of life? Researchers will compare outcomes between patients receiving CTCA prior to angiography and those undergoing standard angiography alone to determine if CTCA improves clinical outcomes and procedural safety.

Participants will:

• Be randomly assigned to either CTCA-guided care or standard angiography
• Undergo coronary imaging and follow-up assessments
• Complete questionnaires on quality of life and healthcare resource use

Study Overview

• Status: Recruiting
• Conditions: Coronary Heart Disease
• Intervention / Treatment: Diagnostic test: CTCA

Detailed Description

Patients with prior coronary artery bypass graft (CABG) surgery frequently present with recurrent angina or acute coronary syndromes due to progressive native coronary artery disease or graft failure. Invasive coronary angiography remains the standard diagnostic approach but is technically challenging in this population due to variable graft anatomy, leading to prolonged procedure times, increased radiation exposure, higher contrast volumes, and elevated risk of procedural complications.

Computed Tomography Coronary Angiography (CTCA) offers a non-invasive alternative with high diagnostic accuracy for graft patency and coronary anatomy. Prior observational data (e.g., BYPASS-CTCA study) suggest that CTCA performed prior to invasive angiography may improve procedural efficiency and safety. However, whether CTCA can guide clinical decision-making to avoid unnecessary angiography and improve long-term outcomes remains unproven.

This multi centre, randomised controlled trial will enrol 1,000 patients with prior CABG presenting with angina or myocardial infarction. Participants will be randomised to either a CTCA-guided strategy or standard care involving direct invasive coronary angiography. In the CTCA arm, angiography may be deferred if CTCA findings support medical management. The primary outcome is the composite rate of major adverse cardiovascular events (MACE), including death, myocardial infarction, stroke, and hospitalisation for unstable angina. Secondary outcomes include procedural metrics, patient-reported quality of life, cost-effectiveness, and healthcare resource utilization.

Clinical data will be collected through patient questionnaires, procedural records, and central registry downloads. The study incorporates patient and public involvement throughout its design and implementation. Results will be disseminated via peer-reviewed publications, public-facing reports, and digital platforms.

• Study Type: Interventional
• Enrollment (Estimated): 1000
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Mervyn Andiapen; Phone Number: 0203 765 8707; Email: mervyn.andiapen@nhs.net
• Study Contact Backup: Name: Matthew Kelham, MBBS, MD; Email: m.kelham@nhs.net

Study Locations

• United Kingdom
  • London, United Kingdom
    • Recruiting
    • St Bartholomew's Hospital
    • Contact: Krishna Rathod; Phone Number: 02037658707

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged ≥18
• Previous coronary artery bypass grafting (CABG)

• An indication for coronary angiography

  • Angina
  • Ischaemia on perfusion imaging
  • Acute coronary syndrome
• Patients are able and willing to give their written informed consent

Exclusion Criteria:

• Subjects presenting with ST segment myocardial infarction within window for primary PCI
• Patients considered unsuitable to participate by the research team (e.g. due to medical reasons, laboratory abnormalities, or subject's unwillingness to comply with all study related procedures)
• Life expectancy less than 1 year

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: ICA only; Invasive coronary angiogram (ICA) performed only.
Active Comparator: CTCA with or without ICA; Computed Tomography Cardiac Angiography (CTCA) with or without invasive coronary angiogram (ICA)	Diagnostic test: CTCA; Computed Tomography Cardiac angiography (CTCA) performed prior to invasive coronary angiogram (ICA).; Other Names: Computed Tomography Cardiac angiography

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite major adverse cardiovascular events (MACE): all-cause mortality, non-fatal stroke, non-fatal myocardial infarction, and cardiovascular hospitalisation	Clinical events will be assessed from randomisation until the final patient completes 6 months of follow-up. The composite endpoint includes all-cause mortality, non-fatal stroke, non-fatal myocardial infarction, and cardiovascular hospitalisation. Based on a 2-year recruitment period, individual follow-up will range from 0.5 to 2.5 years, with an estimated median follow-up of 18 months.	Up to 2.5 years post-randomisation (median follow-up: 18 months)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fluoroscopy time during coronary angiography	Unit of Measure: Minutes	During coronary angiography procedure
Incidence of procedural complications during coronary angiography	Unit of Measure: Number of participants with event	During coronary angiography procedure
Radiation dose during coronary angiography	Unit of Measure: Milligray (mGy)	During coronary angiography procedure
Contrast dose administered during coronary angiography	Unit of Measure: Milliliters (mL)	During coronary angiography procedure
Procedural duration during coronary angiography	Unit of Measure: Minutes Unit of Measure: Milliliters (mL)	During coronary angiography procedure
Health-related quality of life (EQ-5D-5L)	Assessed using the EQ-5D-5L questionnaire at baseline and every 6 months during follow-up.	Baseline, 6 months, 12 months, 18 months, and 24 months
Cost-effectiveness and productivity loss	Evaluated using patient questionnaires capturing healthcare resource use and productivity loss at baseline and every 6 months.	Baseline and every 6 months during follow-up
Days alive and out of hospital	Total number of days the participant is alive and not admitted to hospital during the follow-up period. Unit of Measure: Days	From randomisation until end of follow-up (up to 2.5 years)
Length of hospital stay	Cumulative duration of hospital admissions during the follow-up period Unit of Measure: Days	From randomisation until end of follow-up (up to 2.5 years)
Major Adverse Cardiovascular Events (MACE) - Individual components	Cumulative duration of hospital admissions during the follow-up period Unit of Measure: Number of events	From randomisation until end of follow-up (up to 2.5 years)
Composite two-point MACE (death and MI)	Includes death and myocardial infarction as a simplified composite cardiovascular endpoint.	From randomisation until end of follow-up (up to 2.5 years)
Major Adverse Cardiovascular Events (MACE) - Cumulative incidence	Total number of MACE events per participant during the follow-up period. Unit of Measure: Number of events	From randomisation until end of follow-up (up to 2.5 years)
Unplanned revascularisation	Number of unplanned coronary revascularisation procedures performed during follow-up. Unit of Measure: Number of procedures	From randomisation until end of follow-up (up to 2.5 years)
Cardiovascular imaging utilisation	Number and type of cardiovascular imaging procedures performed during follow-up. Unit of Measure: Number of procedures	From randomisation until end of follow-up (up to 2.5 years)

Collaborators and Investigators

• Sponsor: Queen Mary University of London
• Collaborators: National Institute for Health Research, United Kingdom
• Investigators: Principal Investigator: Daniel Jones, MRCP, PhD, Queen Mary University of London

Study record dates

Study Major Dates

• Study Start (Actual): April 16, 2026
• Primary Completion (Estimated): July 31, 2029
• Study Completion (Estimated): July 31, 2029

Study Registration Dates

• First Submitted: August 15, 2025
• First Submitted That Met QC Criteria: September 2, 2025
• First Posted (Actual): September 10, 2025

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Coronary Artery Disease; percutaneous coronary intervention; Angina; CABG; Coronary Artery Bypass Graft; CTCA; coronary angiograms; Computerised Tomography Coronary Angiography
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Vascular Diseases; Cardiovascular Diseases; Heart Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Myocardial Ischemia; Chest Pain; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Coronary Artery Disease; Coronary Disease; Angina Pectoris
• Other Study ID Numbers: 341412; NIHR207209 (Other Grant/Funding Number: NIHR Research for Patient Benefit); PR2300245 (Other Grant/Funding Number: Siemens Healthcare Limited)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data sharing available from corresponding author upon reasonable request and with approval from trial steering committee.
• IPD Sharing Time Frame: 2028
• IPD Sharing Access Criteria: Freely available via journal
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No