Jonathan Avrom Leipsic MD, Presenter: Speakers Bureau, General Electric Company Medical Advisory Board, General Electric Company

Bon-Kwon Koo, Abstract Co-Author: Nothing to Disclose

Andrejs Erglis, Abstract Co-Author: Nothing to Disclose

David Daniels, Abstract Co-Author: Nothing to Disclose

Joon-Hyun Doh, Abstract Co-Author: Nothing to Disclose

Hyo-Soo Kim, Abstract Co-Author: Nothing to Disclose

James K. Min, Abstract Co-Author: Speakers Bureau, General Electric Company Medical Advisory Board, General Electric Company

Computational fluid dynamics applied to coronary computed tomographic angiogram (CCTA) images provides a new method for non-invasive calculation of fractional flow reserve (cFFR). The diagnostic accuracy of cFFR specifically for intermediate coronary artery lesions has not been thoroughly examined.

We performed a prospective multicenter study of patients undergoing CCTA, and clinically-indicated invasive coronary angiography (ICA) and measured FFR (mFFR). Quantitative coronary angiography (QCA) identified lesions between 40-69% stenosis in coronary arteries ≥1.5mm. An mFFR ≤0.80 was considered diagnostic of lesion-specific ischemia. Separate, blinded, independent core laboratories evaluated ischemia in relationship to cFFR≤0.80 and CCTA stenosis severity ≥50%.

76 vessels from 55 patients at 4 centers underwent CCTA, QCA, mFFR and cFFR. 41 vessels were identified between 40-69% on QCA, of which 15 had mFFR ≤0.80. The performance of cFFR and CCTA stenosis severity for the diagnosis of ischemia by mFFR was -Accuracy 87.8% cFFR vs. 51.2% CCTA. Sens 93.3% cFFR vs 93.3% CT. Specficity 84.6% cFFR vs 26.9% CT. PPV 77.8% cFFR vs. 42.4% CT and NPV 95.7% cFFR vs. 87.5% CT. cFFR reduced false positives by nearly 5x without a change in false negatives compared to CCTA alone. The area under the receiver operator characteristics curve to diagnose an ischemic lesion was 0.92 for cFFR and 0.72 for CCTA stenosis (p<0.01 for difference). cFFR and mFFR values were well correlated (r=0.73, p<0.001) without significant mean differences (1.8+12.6%, p=0.33)

In this prospective multicenter study of patients with intermediate coronary artery stenoses, cFFR demonstrated high diagnostic performance for the detection and exclusion of lesion-specific ischemia. The addition of cFFR to CCTA-identified lesions of intermediate stenosis severity may help guide referral of appropriate patients to invasive angiography and revascularization.

cFFR demonstrates high diagnostic performance for the detection and exclusion of lesion specific ischemia which may allow for more appropriate catheterization and revascularization. 

Leipsic, J, Koo, B, Erglis, A, Daniels, D, Doh, J, Kim, H, Min, J, Diagnostic Performance of Noninvasive Computational Fractional Flow Reserve by Coronary Computed Tomographic Angiography for Intermediate Lesions between 40-69% Stenosis: A Prospective Multicenter Study.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11009169.html