Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Eur Heart J Cardiovasc Imaging. 2012 Dec;13(12):1001-7. doi: 10.1093/ehjci/jes130. Epub 2012 Jul 15.
We validated and compared transluminal attenuation gradient (TAG) and corrected coronary opacification (CCO) of coronary computed tomography angiography (CCTA) with invasively measured fractional flow reserve (FFR).
One of the major limitations of CCTA is the discrepancy between angiographical stenosis and ischaemia-causing stenosis. Recently two new CCTA analysis methods, TAG and CCO, have been attempted to overcome this limitation but without physiological validation.
We measured TAG and CCO of 97 major epicardial coronary arteries from 63 patients who underwent CCTA and followed by invasive coronary angiography and FFR. Diagnostic performance of TAG and CCO was assessed using FFR <0.80 as the reference standard. The overall diagnostic performance of TAG and CCO on a per-vessel basis was moderate and similar (c-statistic = 0.696 vs. 0.637, P = 0.29). The sensitivity, specificity, positive, and negative predictive values of TAG cut-off ≤-0.654 for FFR <0.80 were 47.5, 91.2, 79.2, and 71.2%, and those of CCO cut-off >0.063 were 65.0, 61.4, 54.2, and 71.4%. TAG showed an incremental value to the diagnostic performance of CCTA but CCO did not (c-statistic =0.726 vs. 0.809, P = 0.025; c-statistic =0.726 vs. 0.784, P = 0.09). In net reclassification improvement (NRI) analysis, addition of TAG to CCTA did not result in significant reclassification (NRI = 1.0%, P = 0.41) and addition of CCO to CCTA resulted in negative reclassification (NRI = -9.3%, P = 0.036).
Intracoronary attenuation-based CCTA analyses, TAG and CCO, showed moderate correlation with physiological coronary artery stenosis. The incremental value of TAG or CCO to the evaluation of haemodynamically stenosis by CCTA seemed to be limited.
我们通过与有创测量的血流储备分数（FFR）比较，验证并比较冠状动脉计算机断层血管造影术（CCTA）的管腔衰减梯度（TAG）和校正的冠状动脉不透射率（CCO）。
CCTA 的主要局限性之一是血管造影狭窄与引起缺血的狭窄之间存在差异。最近，两种新的 CCTA 分析方法，TAG 和 CCO，已被尝试用来克服这一局限性，但没有进行生理学验证。
我们对 63 例接受 CCTA 并随后进行有创冠状动脉造影和 FFR 的患者的 97 条主要心外膜冠状动脉进行了 TAG 和 CCO 测量。使用 FFR<0.80 作为参考标准评估 TAG 和 CCO 的诊断性能。基于每支血管的 TAG 和 CCO 的总体诊断性能中等且相似（C 统计量=0.696 与 0.637，P=0.29）。TAG 截断值≤-0.654 对 FFR<0.80 的敏感性、特异性、阳性预测值和阴性预测值分别为 47.5%、91.2%、79.2%和 71.2%，CCO 截断值>0.063 分别为 65.0%、61.4%、54.2%和 71.4%。TAG 显示对 CCTA 诊断性能有增量价值，但 CCO 没有（C 统计量=0.726 与 0.809，P=0.025；C 统计量=0.726 与 0.784，P=0.09）。在净重新分类改善（NRI）分析中，将 TAG 添加到 CCTA 并没有导致显著的重新分类（NRI=1.0%，P=0.41），而将 CCO 添加到 CCTA 导致负重新分类（NRI=-9.3%，P=0.036）。
基于冠状动脉内衰减的 CCTA 分析，TAG 和 CCO 与生理冠状动脉狭窄显示出中度相关性。TAG 或 CCO 对 CCTA 评估血流动力学狭窄的增量价值似乎有限。
