Coronary CT angiography derived morphological and functional quantitative plaque markers correlated with invasive fractional flow reserve for detecting hemodynamically significant stenosis.

Compare morphological and functional coronary plaque markers derived from coronary CT angiography (CCTA) for their ability to detect lesion-specific ischemia. Data of patients who had undergone both dual-source CCTA and invasive fractional flow reserve (FFR) measurement within 3 months were retrospectively analyzed. Various quantitative stenosis markers were derived from CCTA: Corrected coronary opacification (CCO), transluminal attenuation gradient (TAG), remodeling index (RI), computational FFR (cFFR), lesion length (LL), vessel volume (VV), total plaque volume (TPV), and calcified and non-calcified plaque volume (CPV and NCPV). Discriminatory power of these markers for flow-limiting versus non-significant coronary stenosis was assessed against invasive FFR as the reference standard. The cohort included 37 patients (61 ± 12 years, 68% male). Among 37 lesions, 11 were hemodynamically significant by FFR. On a per-lesion level, sensitivity and specificity of TPV, CPV, and NCPV for hemodynamically significant stenosis detection were 88% and 74%, 67% and 53%, and 92% and 81%, respectively. For CCO, TAG, RI, and cFFR these were 64% and 86%, 35% and 56%, 82% and 54%, and 100% and 90%, respectively. At ROC analysis, only TPV (0.78, p = 0.013), NCPV (0.79, p = 0.009), cFFR (0.85, p = 0.003), and CCO (0.82, p = 0.0003) showed discriminatory power for detecting hemodynamically significant stenosis. TPV, NCPV, CCO, and cFFR derived from CCTA can aid detecting hemodynamically significant coronary lesions with cFFR showing the greatest discriminatory ability.

Tesche C ，De Cecco CN ，Caruso D ，Baumann S ，Renker M ，Mangold S ，Dyer KT ，Varga-Szemes A ，Baquet M ，Jochheim D ，Ebersberger U ，Bayer RR 2nd ，Hoffmann E ，Steinberg DH ，Schoepf UJ ... -  《-》

Coronary CT angiography derived plaque markers correlated with invasive instantaneous flow reserve for detecting hemodynamically significant coronary stenoses.

The study aimed to compare morphological and anatomic plaque markers derived from coronary computed tomography angiography (cCTA) for the detection of lesion specific ischemia with invasive instantaneous wave free ratio (iFR®) as the reference standard. In our prospective study, we enrolled patients with suspected coronary artery disease (CAD), who had undergone cCTA, using a low-dose third-generation dual-source CT and invasive coronary angiography (ICA) with iFR® measurement. Various plaque markers were assessed on cCTA. Discriminatory power of these markers for the detection of ischemia-inducing coronary artery disease was evaluated against invasive iFR®. Our study cohort included 39 patients (66.6 ± 12.0 years, 72 % male). Among 54 vessel-specific lesions, 15 lesions (28 %) were characterized as hemodynamically significant by iFR® ≤0.89. The area under the curve (AUC) of lesion length/ minimal luminal diameter4 (LL/MLD4) (0.84) was greater than the AUC of minimal luminal area (MLA) (0.82), MLD (0.81), the degree of luminal diameter stenosis (0.81), corrected coronary opacification (CCO) (0.79), remodeling index (RI) (0.75), and percentage aggregate plaque volume (%APV) (0.72). LL, vessel volume (VV), total plaque volume (TPV), calcified and non-calcified plaque volume (CPV and NCPV) did not reach statistical significance and were unable to discriminate between vessels with and without ischemia-inducing coronary stenosis. LL/MLD4, MLA, MLD, the degree of luminal diameter stenosis, CCO, RI, and %APV derived from cCTA can support the detection of hemodynamically significant coronary stenosis as compared with iFR®, with LL/MLD4 showing the greatest discriminatory power.

Baumann S ，Özdemir GH ，Tesche C ，Schoepf UJ ，Golden JW ，Becher T ，Hirt M ，Weiss C ，Renker M ，Akin I ，Schoenberg SO ，Borggrefe M ，Haubenreisser H ，Lossnitzer D ，Overhoff D ... -  《-》

Noninvasive diagnosis of ischemia-causing coronary stenosis using CT angiography: diagnostic value of transluminal attenuation gradient and fractional flow reserve computed from coronary CT angiography compared to invasively measured fractional flow reser

The aim of this study was to compare the diagnostic performance of coronary computed tomography angiography (CCTA)-derived computed fractional flow reserve (FFR(CT)) and transluminal attenuation gradient (TAG) for the diagnosis of lesion-specific ischemia. Although CCTA is commonly used to detect coronary artery disease (CAD), it cannot reliably assess the functional significance of CAD. Novel technologies based on CCTA were developed to integrate anatomical and functional assessment of CAD; however, the diagnostic performance of these methods has never been compared. Fifty-three consecutive patients who underwent CCTA and coronary angiography with FFR measurement were included. Independent core laboratories determined CAD severity by CCTA, TAG, and FFR(CT). The TAG was defined as the linear regression coefficient between intraluminal radiological attenuation and length from the ostium; FFR(CT) was computed from CCTA data using computational fluid dynamics technology. Among 82 vessels, 32 lesions (39%) had ischemia by invasive FFR (FFR ≤0.80). Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratio of TAG (≤ -0.654 HU/mm) for detection of ischemia were 38%, 88%, 67%, 69%, 3.13, and 0.71, respectively; and those of FFR(CT) were 81%, 94%, 90%, 89%, 13.54, and 0.20, respectively. Receiver-operating characteristic curve analysis showed a significantly larger area under the curve (AUC) for FFR(CT) (0.94) compared to that for TAG (0.63, p < 0.001) and CCTA stenosis (0.73, p < 0.001). In vessels with noncalcified plaque or partially calcified plaque, FFR(CT) showed a larger AUC (0.94) compared to that of TAG (0.63, p < 0.001) or CCTA stenosis (0.70, p < 0.001). In vessels with calcified plaque, AUC of FFR(CT) (0.92) was not statistically larger than that of TAG (0.75, p = 0.168) or CCTA stenosis (0.80, p = 0.195). Noninvasive FFR computed from CCTA provides better diagnostic performance for the diagnosis of lesion-specific ischemia compared to CCTA stenosis and TAG.

Yoon YE ，Choi JH ，Kim JH ，Park KW ，Doh JH ，Kim YJ ，Koo BK ，Min JK ，Erglis A ，Gwon HC ，Choe YH ，Choi DJ ，Kim HS ，Oh BH ，Park YB ... -  《-》

Comparison of quantitative stenosis characteristics at routine coronary computed tomography angiography with invasive fractional flow reserve for assessing lesion-specific ischemia.

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). 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]). 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. 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. LL/MLD(4) derived from routine cCTA can enhance the detection of lesion-specific ischemia and may be superior to other described quantitative parameters.

Wang R ，Baumann S ，Schoepf UJ ，Meinel FG ，Rier JD ，Morris JZ ，Möllmann H ，Hamm CW ，Steinberg DH ，Renker M ... -  《-》

Diffuse coronary artery disease among other atherosclerotic plaque characteristics by coronary computed tomography angiography for predicting coronary vessel-specific ischemia by fractional flow reserve.

Coronary computed tomography angiography (CCTA) permits effective identification of diffuse CAD and atherosclerotic plaque characteristics (APCs). We sought to examine the usefulness of diffuse CAD beyond luminal narrowing and APCs by CCTA to detect vessel-specific ischemia. 407 vessels (n = 252 patients) from the DeFACTO diagnostic accuracy study were retrospectively analyzed for percent plaque diffuseness (PD). Percent plaque diffuseness (PD) was obtained on per-vessel level by summation of all contiguous lesion lengths and divided by total vessel length, and was logarithmically transformed (log percent PD). Additional CCTA measures of stenosis severity including minimal lumen diameter (MLD), and APCs, such as positive remodeling (PR) and low attenuation plaque (LAP), were also included. Vessel-specific ischemia was defined as fractional flow reserve (FFR) ≤0.80. Multivariable regression, discrimination by area under the receiver operating characteristic curve (AUC), and category-free net reclassification improvement (cNRI) were assessed. Backward stepwise logistic regression revealed that for every unit increase in log percent PD, there was a 58% (95% CI: 1.01-2.48, p = 0.048) rise in the odds of having an abnormal FFR, independent of stenosis severity and APCs. The AUC indicated no further improvement in discriminatory ability after adding log percent PD to the final parsimonious model of MLD, PR, and LAP (AUC difference: 0.003, 95% CI: -0.003-0.010, p = 0.33). Conversely, adding log percent PD to the base model of MLD, PR, and LAP improved cNRI by 0.21 (95% CI: 0.01-0.41, p < 0.001). Accounting for diffuse CAD may help improve the accuracy of CCTA for detecting vessel-specific ischemia.

Rizvi A ，Hartaigh BÓ ，Danad I ，Han D ，Lee JH ，Gransar H ，Szymonifka J ，Lin FY ，Min JK ... -  《-》