Comparison of quantitative stenosis characteristics at routine coronary computed tomography angiography with invasive fractional flow reserve for assessing lesion-specific ischemia.
OBJECTIVE
To comprehensively evaluate quantitative parameters derived from routine coronary CT angiography (cCTA) for predicting lesion-specific ischemia in comparison to invasive fractional flow reserve (FFR).


BACKGROUND
The ability of cCTA to gauge lesion-specific ischemia is limited. Several quantitative parameters have been proposed to enhance the specificity of cCTA, such as morphologic indices (lesion length/minimal lumen diameter(4) [LL/MLD(4)]; percentage aggregate plaque volume [%APV]) and a measure of intracoronary contrast gradients (corrected coronary opacification [CCO]).


METHODS
Forty-nine patients who had undergone cCTA followed by FFR within 3 months were included. An experienced observer visually assessed all cCTA studies and derived multiple measures characterizing the lesion of interest, including LL, MLD, minimal lumen area (MLA), LL/MLD(4), remodeling index, %APV, and CCO. Lesion-specific ischemia was considered with FFR <0.8.


RESULTS
Among 56 lesions, 13 were flow-obstructing by FFR. On univariate analysis, LL, MLD, LL/MLD(4), and CCO showed discriminatory power. The area under the curve of LL/MLD(4) (0.909) was significantly greater compared with MLD (0.802, P = 0.014), LL (0.739, P = 0.041), and CCO (0.809), although the latter did not reach statistical significance (P = 0.175). On multivariate regression, LL/MLD(4) was the only independent predictor of lesion-specific ischemia (odds ratio 2.021, P = 0.001). Moreover, LL/MLD(4) compared favorably to visual cCTA evaluation.


CONCLUSIONS
LL/MLD(4) derived from routine cCTA can enhance the detection of lesion-specific ischemia and may be superior to other described quantitative parameters.
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA; Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China. Electronic address: rui_wang1979@hotmail.com.
Rui
R
Wang
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA; First Department of Medicine, Faculty of Medicine Mannheim, University Medical Centre, Mannheim (UMM), University of Heidelberg, Mannheim, Germany. Electronic address: stefanbaumann@gmx.at.
Stefan
S
Baumann
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA. Electronic address: schoepf@musc.edu.
U Joseph
UJ
Schoepf
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA; Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany. Electronic address: felix.meinel@med.uni-muenchen.de.
Felix G
FG
Meinel
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA. Electronic address: rier@musc.edu.
Jeremy D
JD
Rier
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA. Electronic address: jstn.morris821@gmail.com.
Justin Z
JZ
Morris
Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany. Electronic address: h.moellmann@kerckhoff-klinik.de.
Helge
H
Möllmann
Department of Medicine I, University Hospital Giessen and Marburg, Giessen, Germany. Electronic address: christian.hamm@innere.med.uni-giessen.de.
Christian W
CW
Hamm
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA. Electronic address: steinbe@musc.edu.
Daniel H
DH
Steinberg
Heart & Vascular Center, Medical University of South Carolina, Charleston, SC, USA; Department of Medicine I, University Hospital Giessen and Marburg, Giessen, Germany. Electronic address: matthias.renker@web.de.
Matthias
M
Renker
D000368:Aged; D019540:Area Under Curve; D006328:Cardiac Catheterization; D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed
Coronary CT angiography; Coronary artery disease; Fractional flow reserve; Invasive coronary angiography