Diagnostic Performance of Target-position Murray Law based Quantitative Flow Ratio (target-μFR) vs Vessel-μFR in Patients with stable Coronary Artery Disease

Abstract

Background: We aim to compare with the diagnostic performance of target-position quantitative flow ratio derived from Murray Law (target-μFR) and vessel quantitative flow ratio derived from Murray Law (vessel-μFR) using the fractional flow reserve (FFR) as reference standard. This study may provide more evidence for the novel clinical usage of target-μFR in the diagnosis of coronary artery disease. Methods: Six hundreds and fifty-six patients (685 lesions) with known or suspected coronary artery disease were screened for this retrospective analysis between January 2021 to March 2023. A total of 161 patients (190 lesions) underwent quantitative coronary angiography and FFR evaluations. Both of target-μFR and vessel-μFR were compared the diagnostic performance using the FFR≤0.80 as the reference standard. Results: Both target-μFR (R=0.90) and vessel-μFR (R=0.87) demonstrated a strong correlation with FFR, and both methods showed great agreement with FFR. The area under the receiver operating characteristic curve was 0.937 for target-μFR and 0.936 for vessel-μFR in predicting FFR≤0.80. FFR≤0.80 were predicted with high sensitivity (92.98%), specificity (91.01%) and the Youden index (0.840) using the cutoff value of 0.83 for target-μFR. A good diagnostic performance (sensitivity 86.44%, specificity 88.51% and Youden index 0.750) was also demonstrated by vessel-μFR which the cutoff value was 0.80. Conclusion: The target-μFR has the similar diagnostic performance with vessel-μFR. The accuracy of μFR does not seem to be affected by the selection of the measurement point. Both of the virtual model could be used as computations tools for diagnosing ischemia and to aid clinical decision-making.