The diagnostic performance of SPECT-MPI to predict functional significant coronary artery disease by fractional flow reserve derived from CCTA (FFR_CT): sub-analysis from ACCURACY and VCT001 studies

Although single photon emission computed tomography-myocardial perfusion image (SPECT-MPI) and fractional flow reserve (FFR) derived from coronary computed tomographic angiography (CCTA) (FFR_CT) have permitted functional assessment of coronary artery disease (CAD), the concordance between these modalities has not been well described. The aim of this study is to compare SPECT-MPI and anatomical stenosis by CCTA and invasive coronary angiography to FFR_CT for assessing functional significance of CAD. We identified 62 patients with suspected CAD who underwent ≥64 slice coronary CTA and SPECT-MPI within 3 months. FFR_CT was analyzed from CCTA data using the computational fluid dynamic techniques. The association between SPECT-MPI ischemia and FFR_CT (≤0.80) was evaluated. Out of 62 patients, 186 vessels were evaluated. On a per-vessel analysis, accuracy, sensitivity and specificity of SPECT-MPI to predict FFR_CT ≤ 0.80 was 74.2, 45.0 and 77.7%, respectively. The area under the curve (AUC) by receiver-operating characteristic curve analysis for SPECT-MPI demonstrated a modest performance for predicting FFR_CT ≤ 0.80 (AUC 0.56). Among patients with suspected CAD who were assessed by non-invasive functional modalities, SPECT-MPI showed modest concordance with FFR_CT.