Yue Ma, Presenter: Nothing to Disclose

Hou Yang MD, Abstract Co-Author: Nothing to Disclose

Yuke Wang, Abstract Co-Author: Nothing to Disclose

Qiyong Guo MD, Abstract Co-Author: Nothing to Disclose

Mei Yu, Abstract Co-Author: Nothing to Disclose

Yingying Hou MS, Abstract Co-Author: Nothing to Disclose

To determine whether iFR-CT using end-diastole resting coronary CT angiography (CTA) can be used to predict the functional stenosis defined by invasive FFR measurement.  

We retrospectively examined the performance of iFR-CT versus FFR at the time of invasive angiography in 19 vessels of 15 patients who were identified as having an intermediate stenosis（diameter reduction from 50% to 70%）defined by coronary CT angiography. Patient-specific models were built by input original resting end-diastolic high-quality DICOM format coronary CTA images (usually R-R interval 75-80%） into Mimics software. The models were surface-meshed and body-meshed, then coupled model of vessel wall and blood was established by using the finite element method．These data results were imported into ANSYS software for visualized pictures of parameter distributions. Computed iFR-CT was obtained by dividing end-diastole resting mean pressure distal to the coronary stenosis by the mean aortic pressure based on the visualized pictures. The correlation between iFR-CT and invasive FFR was determined with Spearman’s rank correlation. And the diagnostic efficiency of iFR-CT for functional ischemia was evaluated with FFR as “gold standard”.  

The difference between noninvasive iFR-CT and invasive FFR was not significant (0.813±0.086 Vs 0.828±0.091, p=0.163). Correlation coefficient between iFR-CT with FFR was 0.811 (P<0.001). iFR-CT had equally good diagnostic agreement with FFR (receiver-operating characteristic area under the curve 0.92, p=0.002). Diagnostic accuracy of iFR-CT to predict lesion-specific ischemia (FFR≤0.8) was 84.2% (sensitivity: 87.5%, specificity: 81.8%, positive predictive value:77.8%, and negative predictive value: 90.0%).  

iFR-CT as a noninvasive, adenosine-independent technology has a significant correlation with invasively measured FFR. iFR-CT appears to be a promising index to assess the functional ischemia of coronary stenosis.  

Computed tomography-derived instantaneous wave-free ratio (iFR-CT) is a novel noninvasive, adenosine-independent technology that can be used for patients with coronary artery disease (CAD) to assess functional stenosis.  

Ma, Y, Yang, H, Wang, Y, Guo, Q, Yu, M, Hou, Y, The Relationship between Instantaneous Wave-free Ratio Computed from Coronary CT Angiography (iFR-CT) and Invasively Measured Fractional Flow Reserve (FFR) in Patients with Coronary Artery Stenosis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14012266.html