Computed tomography coronary angiography to facilitate clinical decision-making and selective invasive angiography in patients with prior bypass grafting presenting with acute coronary syndromes

BACKGROUND: Patients with prior coronary artery bypass grafting (CABG) account for around 10% of non-ST-elevation acute coronary syndromes (NSTE-ACS), but the optimal diagnostic and management strategy remains uncertain. Invasive coronary angiography (ICA) in this group is technically challenging, carries increased risk and often does not lead to percutaneous coronary intervention (PCI). CT coronary angiography (CTCA) may help identify which patients benefit from ICA and reduce unnecessary invasive procedures. METHODS: In the BYPASS-CTCA (Randomised Controlled Trial to Assess Whether Computed Tomography Cardiac Angiography Can Improve Invasive Coronary Angiography in Bypass Surgery Patients) study, patients with prior CABG undergoing ICA were randomised to CTCA plus ICA or ICA alone. For this analysis, anonymised case vignettes and CTCA reports from 150 patients with NSTE-ACS were independently reviewed by 50 experienced interventional cardiologists (median 17 years post-qualification; 5103 total case reviews). Agreement on management strategy before and after CTCA was assessed using Fleiss' κ statistic. RESULTS: Based on clinical information alone, respondents chose medical therapy in 13.2% of cases, with poor agreement on management strategy (κ=0.14, 95% CI 0.11 to 0.17). After reviewing CTCA, agreement improved to moderate (κ=0.53, 95% CI 0.48 to 0.58; p