Head-to-head comparison of computed tomography–derived fractional flow reserve and single-photon emission computed tomography for the diagnosis of myocardial ischemia: first Egyptian experience

Abstract Background Coronary artery disease is a global health issue that requires accurate diagnosis to guide treatment. While myocardial perfusion imaging (MPI) methods like SPECT are widely used, CT-derived fractional flow reserve (FFR-CT) is a new, noninvasive technique that provides both anatomical and functional assessment using coronary CT angiography. Objective This study aimed for head-to-head comparison of the diagnostic performance of FFR-CT with that of SPECT in detecting functionally significant coronary artery disease. Methods A total of 85 patients were evaluated using both FFR-CT and SPECT imaging. Diagnostic parameters, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy, were calculated. Subgroup analyses were conducted for individual coronary artery territories (LAD, LCx, RCA). Results FFR-CT demonstrated high diagnostic performance, with a specificity of 83.1%, an NPV of 92.8%, and an overall accuracy of 80.9% on patient level. On vessel-based analysis, it achieved almost 100% diagnostic accuracy for ischemia in the LAD and LCx territories (Kappa = 0.941 and 1.0, respectively). Sensitivity for the RCA was lower at 66.7%. Conclusion FFR-CT provides robust functional assessment combined with anatomical data of the coronary artery disease, offering comparable diagnostic performance to SPECT and an effective gatekeeper to invasive angiography.