The value of hybrid functional and anatomical imaging for guiding revascularization decision-making by the heart team in patients with prior coronary artery bypass grafting

Background Coronary computed tomography angiography (CCTA) and myocardial perfusion imaging (MPI) are guideline-recommended to assist in clinical decision-making in patients with prior coronary artery bypass grafting (CABG). However, the value of combining CCTA and MPI for guiding revascularization decision-making in post-CABG patients with recurrent ischemic symptoms remains unexplored. In this study, we compared Heart Team strategies for revascularization based on CCTA and MPI as standalone and hybrid CCTA/MPI imaging, to strategies guided by invasive coronary angiography (ICA). Methods We included symptomatic patients with prior CABG who underwent CCTA and MPI (single-photon emission computed tomography, positron emission tomography or stress perfusion cardiac magnetic resonance imaging) preceding ICA. Simulated Heart Teams, blinded to other Heart teams and outcomes, performed revascularization decision-making based on conventional CCTA, MPI and a hybrid CCTA/MPI strategy (non-invasive Heart Team) or based on ICA (invasive Heart Team). The primary outcome was the Cohen’s kappa agreement (κ) between non-invasive and invasive Heart Teams. Results A total of 115 patients (mean age 73±7 years; 99 [86%] male) were included. Revascularization was recommended in 96 patients (83.5%) by CCTA, 92 patients (80.0%) by MPI, 80 patients (69.6%) by hybrid CCTA/MPI and 76 patients (66.1%) by ICA. The agreements were significant but low for CCTA (κ: 0.25 [95% confidence interval (CI): 0.07-0.42], P=0.003) and MPI (κ: 0.27 [95% CI: 0.09-0.48], P=0.002) compared to ICA, with only a modest increase when using the hybrid non-invasive imaging strategy (κ: 0.32 [95% CI: 0.14-0.51], P<0.001). Conclusions In patients with recurrent ischemic symptoms after CABG, Heart Team assessment of conventional CCTA and MPI yielded similarly poor agreements with revascularization strategies based on ICA, with only a modest improvement observed when using a hybrid CCTA/MPI approach. Overall, non-invasive imaging alone appears insufficient to accurately guide treatment strategies in patients with prior CABG, and their use as gatekeeping for ICA in these patients should be questioned.