CTCA Prior to Invasive Coronary Angiography in Patients With Previous Bypass Surgery: Patient-Related Outcomes, Imaging Resource Utilization, and Cardiac Events at 3 Years From the BYPASS-CTCA Trial.

Background: In patients with previous coronary artery bypass grafting, computed tomography cardiac angiography (CTCA) before invasive coronary angiography (ICA) was demonstrated in the BYPASS-CTCA trial (Randomized Controlled Trial to Assess Whether Computed Tomography Cardiac Angiography Can Improve Invasive Coronary Angiography in Bypass Surgery Patients) to reduce procedure time and incidence of contrast-associated acute kidney injury, with greater levels of patient satisfaction. Patient-related outcomes, utilization of further diagnostic imaging resources, and longer-term incidence of major adverse cardiac events were key secondary end points not yet reported.

Methods: Patients with prior coronary artery bypass grafting referred for ICA were randomized 1:1 to undergo CTCA before ICA or ICA alone and followed up for a median of 3 (2.2-3.4) years. Angina status was assessed using the Seattle Angina Questionnaire and overall quality of life using the EQ-5D-5L. The incidence of noninvasive imaging use and major adverse cardiac events were compared between the 2 groups.

Results: In all, 688 patients were randomized, 344 to CTCA+ICA and 344 to ICA only. The mean age of participants was 69.8 years, with 45% undergoing ICA for acute coronary syndromes and the remainder stable angina. At 3 months follow-up, patients in the CTCA+ICA group were more likely to be angina-free (51.7% versus 43.2%; =0.03) with greater quality of life (EQ-5D-5L index, 81.6 versus 74.4; =0.001), although these improvements did not persist. At 3 years follow-up, imaging resource use (35.8% versus 45.1%; odds ratio, 0.68 [95% CI, 0.50-0.92]; =0.013) and incidence of major adverse cardiac events were lower in the CTCA+ICA group (35.8% versus 43.5%; hazard ratio, 0.73 [95% CI, 0.58-0.93]; =0.010).

Conclusions: In patients with prior coronary artery bypass grafting undergoing ICA, CTCA before ICA leads to reductions in the use of imaging resources and the rate of major cardiac events out to 3 years, but with similar patient-related outcome measures. Together with the initial findings of BYPASS-CTCA, these data are supportive of routinely undertaking a CTCA before ICA in patients with prior coronary artery bypass grafting.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03736018.