Utility of Coronary CT Angiography and stress SPECT Myocardial Perfusion Imaging for graft disease assessment in symptomatic patients after coronary artery bypass graft surgery

Abstract

Background: Graft occlusions are commonly present in symptomatic patients after coronary
artery bypass surgery (CABG). The aim of this study was to evaluate the diagnostic accuracy of
coronary computed tomography angiography (CCTA) and stress single photon emission computed
tomographic (SPECT) myocardial perfusion imaging (MPI) for detecting graft disease in
symptomatic post-CABG patients.
Methods: This was a prospective, single centre study of 100 symptomatic post-CABG patients
with native coronary artery/ graft occlusions on invasive angiography (CAG). Grafts were
evaluated for degree of stenosis qualitatively on CCTA. Reversible perfusion defects were graded
using summed difference score (SDS) on MPI. Sensitivity, specificity, positive predictive value
(PPV), negative predictive value (NPV) and accuracy of CCTA and MPI were evaluated against
CAG.