Olivier Ghekiere MD, Presenter: Nothing to Disclose

Willem Dewilde, Abstract Co-Author: Nothing to Disclose

Denis Hoa MD, Abstract Co-Author: Nothing to Disclose

Piet K. Vanhoenacker MD, Abstract Co-Author: Nothing to Disclose

Paul Dendale, Abstract Co-Author: Nothing to Disclose

Alain Longang Nchimi MD, Abstract Co-Author: Nothing to Disclose

Isabelle Mancini, Abstract Co-Author: Nothing to Disclose

Michel Bellekens MD, Abstract Co-Author: Nothing to Disclose

Julien Djekic, Abstract Co-Author: Nothing to Disclose

Thierry Couvreur, Abstract Co-Author: Nothing to Disclose

Tim Coolen, Abstract Co-Author: Nothing to Disclose

To evaluate quantitative coronary angiography (QCA) and fractional flow reserve (FFR) findings in coronary arteries with diameter stenosis between 40 and 70% on coronary computed tomography angiography (CCTA), the so-called intermediate coronary artery stenosis (ICAS)

47 patients (mean age 62±9, range 44-80;34 males) with 51 lesions with minimal lumen diameter (MLD) stenosis percentage (Ds%) at different coronary locations on CCTA prospectively underwent QCA with FFR for each ICAS. In addition, minimal lumen area (MLA), area stenosis percentage (As%), stenosis length (Ls), plaque burden and grade of calcification circumference were evaluated on CCTA by 2 experienced readers. Kappa(κ) and intraclass correlation(ICC) statistics were used for agreement between the readers and between QCA and CCTA for categorical and continuous descriptors of stenosis. Receiver operator characteristics (ROC) statistics were used to evaluate the CCTA and QCA descriptors' values for the diagnosis of hemodynamically significant (FFR < 0.8) stenosis. Bland-Altman statistics were used to assess the correlation between CCTA and QCA assessment.

The inter-reader concordances (k range 0.84-0.88; p < 0.05) were excellent and correlations (ICC range 0.75-0.97;p < 0.05) were significant. A significant inter-technique correlation for MLD (r=0.633, p < 0.001) and Ds% (r=0.633, p=0.04) was found between CCTA and QCA. Best predictors for hemodynamically significant stenosis were 1.35 mm MLD and 2.15 mm² MLA for CCTA and 1.1 mm MLD and 55 Ds% for QCA, with area under the ROC curve (Az) of 0.74 and 0.74, and 0.68 and 0.60 respectively.

There is a excellent interobserver correlation for the ICAS descriptors on CCTA. Futher, the correlations between CCTA and QCA for MLD and Ds% are significant, but the diagnostic values of these descriptors in predicting hemodynamically significant stenosis are equally modest. 

Anatomical assessment of ICAS at CCTA correlates well with QCA, but predicts poorly the hemodynamical significance requiring mostly further functional assessment before treatment. 

Ghekiere, O, Dewilde, W, Hoa, D, Vanhoenacker, P, Dendale, P, Nchimi, A, Mancini, I, Bellekens, M, Djekic, J, Couvreur, T, Coolen, T, Diagnostic Performance of Coronary CT Angiography and Quantitative Coronary Angiography to Predict Functional Significance of Intermediate Coronary Artery Stenosis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14012528.html