Concordance between myocardial perfusion scan assessed by SPECT and fractional flow reserve findings for detection of significant ischemia

Abstract

Background: Myocardial Perfusion Imaging (MPI) plays an imperative role in the diagnosis of myocardial ischemia. On the other hand, fractional flow reserve (FFR) has a number of distinctive characteristics that make it particularly appropriate for the functional assessment of coronary artery stenosis. The present study aimed to assess concordance of MPI with SPECT and FFR findings for detection of significant ischemia. Methods: Forty-five consecutive patients who were candidate for coronary angiography were included into the study and underwent MPI with SPECT. Ischemia was considered significant if the presence of stress induced-ischemia in a wide myocardial area (⩾10%) or stress segmental score indicates multiple vascular territories with abnormalities in MPI with SPECT, or if FFR < 0.75. Results: There was a significant concordance between FFR and MPI with SPECT techniques for detecting ischemia in involved LAD territory (kappa = 0.565, p < 0.001), in LCX territory (kappa = 0.815, p < 0.001), and in RCA territory (kappa = 0.776, p < 0.001). Comparing diagnostic value of SPECT with FFR, as gold standard for detection of ischemia, for LAD involvement, SPECT had sensitivity, specificity, PPV, NPV, and accuracy of 66.7%, 71.0%, 30.8%, 91.7%, and 70.3%, for LCX involvement 100%, 60.0%, 33.4%, 100%, and 66.7% and for RCA involvement, 100%, 60.0%, 20.0%, 100%, and 70.0%, respectively. Conclusion: FFR and MPI with SPECT techniques showed significant concordance for detection of myocardial ischemia, regardless of the type of diseased coronary arteries. In this context, SPECT has high sensitivity and NPV for detection of ischemia compared with FFR.

Keywords

• Perfusion scan
• Fractional flow reserve
• Ischemia