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

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.