摘要目的:探究冠状动脉CTA（CCTA）诊断的狭窄程度与斑块特征联合应用对冠状动脉缺血病变的诊断效能。方法:2018年11月至2020年3月，在全国5家临床试验中心纳入疑诊或已知冠心病并拟行冠状动脉造影（ICA）的患者，所有患者于1周内依次行CCTA、ICA及血流储备分数（FFR）检查。测量并收集所有病变血管的斑块特征，包括斑块负荷、钙化成分体积比、非钙化成分体积比、病变长度、斑块高危征象。以ICA引导下经压力导丝测量的心肌FFR为金标准，将所有病变血管分为FFR≤0.8（缺血）和FFR>0.8（非缺血）2组，比较上述斑块特征在2组中的分布差异；使用logistic回归分析CCTA狭窄率、斑块特征与缺血病变的关系；采用ROC曲线评估CCTA狭窄率、斑块特征相应的灵敏度和特异度，并采用Delong检验对各参数的曲线下面积（AUC）进行两两比较。结果:本研究最终纳入患者共317例，冠状动脉病变血管366支（缺血组血管169支，非缺血组197支）。与非缺血组相比，缺血组病变血管的斑块负荷更大［缺血组34.3%（30.3%，38.8%）、非缺血组32.4%（28.5%，37.9%）； Z=-2.622， P=0.009］，CT高危斑块比例更高［缺血组26.9%（45/169）、非缺血组11.7%（23/197）；χ 2=15.311， P<0.001］，病变长度更长［缺血组22.1（14.4，35.0）mm、非缺血组17.6（11.0，26.0）mm； Z=-4.388， P<0.001］，差异均具有统计学意义。回归分析显示，CCTA狭窄率、病变长度、CT高危斑块是病变导致心肌缺血的危险因素（OR值分别为3.794、2.461、1.027； P<0.001、 P=0.002、 P=0.002）。单独应用CCTA≥50%狭窄诊断缺血病变的AUC是0.625，联合CT斑块特征AUC为0.714（ P<0.001）。 结论:CCTA狭窄率、病变长度及CT高危斑块特征是病变导致心肌缺血的预测因素，联合应用能显著提高CCTA对缺血病变的诊断效能。

abstractsObjective:To probe the diagnostic performance of the combined evaluation of stenosis and plaque characteristics based on coronary computed tomography angiography (CCTA) in identification of myocardial ischemic lesions, using the invasive coronary angiography (ICA)-based fractional flow reserve (FFR) as the gold standard.Methods:From November 2018 to March 2020, the patients with suspected or known coronary artery disease and scheduled for ICA at 5 clinical trials centers were enrolled in this study. All the patients underwent CCTA, ICA and FFR in turn in one week. The luminal stenosis and plaque characteristics were measured and assessed including plaque burden, volume ratios of calcification and non-calcification, lesion length and CT vulnerable features. All culprit vessels were divided into FFR≤0.8 and FFR>0.8 groups, and the parameters of plaque characteristics were compared. The correlation of ischemic lesions with CCTA stenosis and plaque characteristics was analyzed by the logistic regression analysis. The ROC curve was used to evaluate the sensitivity and specificity of CCTA stenosis rate and plaque characteristics, meanwhile the area under curve (AUC) of each parameter was compared by Delong test.Results:Three hundred and sixty-six culprit vessels in 317 patients were analyzed in this study (169 vessels in ischemia group and 197 in nonischemia group). The plaque burden [34.3% (30.3%, 38.8%) vs. 32.4% (28.5%, 37.9%); Z=-2.622, P=0.009], proportion of CT vulnerable features [26.9% (45/169) vs.11.7% (23/197); χ 2=15.311, P<0.001] and lesion length [22.1 (14.4, 35.0) mm vs. 17.6 (11.0, 26.0) mm; Z=-4.388, P<0.001] in FFR≤0.8 group were higher than those in FFR>0.8 group. The results of logistic regression analysis revealed that CCTA stenosis, lesion length, and CT vulnerable features were significant predictors for myocardial ischemia (OR values: 3.794, 2.461, 1.027; P<0.001, P=0.002, P=0.002). The diagnostic performance of CCTA ≥50% stenosis alone in identification of ischemic lesions was low (AUC=0.625). When it combined high-risk plaque characteristics and lesion length, the AUC was improved to 0.714 with a statistical significance. Conclusions:CCTA stenosis, lesion length, and CT vulnerable features are major predictors in identification of myocardial ischemic lesions, and the combination will significantly improve the diagnostic performance of CCTA ≥50% stenosis.