Table_1_Angiographic Lesion Morphology Provides Incremental Value to Generalize Quantitative Flow Ratio for Predicting Myocardial Ischemia.docx

AimThe quantitative flow ratio (QFR) is favorable for functional assessment of coronary artery stenosis without pressure wires and induction of hyperemia. The aim of this study was to explore whether angiographic lesion morphology provides incremental value to generalize QFR for predicting myocardial ischemia in unselected patients.
MethodsThis study was a substudy to the CT-FFR CHINA trial, referring 345 participants from five centers with suspected coronary artery disease on coronary CT angiography for diagnostic invasive coronary angiography (ICA). Fractional flow reserve (FFR) was measured in all vessels with 30–90% diameter stenosis. QFR was calculated in 186 lesions from 159 participants in a blinded manner. In addition, parameters to characterize lesion features were recorded or measured, including left anterior descending arteries (LADs)-involved lesions, side branch located at stenotic lesion (BL), multiple lesions (ML), minimal lumen diameter (MLD), reference lumen diameter (RLD), percent diameter stenosis (%DS), lesion length (LL), and LL/MLD4. Logistic regression was used to construct two kinds of models by combining single or two lesion parameters with the QFR. The performances of these models were compared with that of QFR on a per-vessel level.
ResultsA total of 148 participants (mean age: 59.5 years; 101 men) with 175 coronary arteries were included for final analysis. In total, 81 (46%) vessels were considered hemodynamically significant. QFR correctly classified 82.29% of the vessels using FFR with a cutoff of 0.80 as reference standard. The area under the receiver operating characteristic curve (AUC) of QFR was 0.86 with a sensitivity, specificity, positive predictive value, and negative predictive value of 80.25, 84.04, 81.25, and 83.16%, respectively. The combined models (QFR + LAD + MLD, QFR + LAD + %DS, QFR + BL + MLD, and QFR + BL + %DS) outperformed QFR with higher AUCs (0.91 vs. 0.86, P = 0.02; 0.91 vs. 0.86, P = 0.02; 0.91 vs. 0.86, P = 0.02; 0.90 vs. 0.86, P = 0.03, respectively). Compared with QFR, the sensitivity of the combined models (QFR + BL and QFR + MLD) was improved (91.36 vs. 80.25%, 91.36 vs. 80.25%, respectively, both P < 0.05) without compromised specificity or accuracy.
ConclusionCombined with angiographic lesion parameters, QFR can be optimized for predicting myocardial ischemia in unselected patients.

研究目的：定量血流分数（quantitative flow ratio, QFR）无需压力导丝与充血诱导即可完成冠状动脉狭窄的功能学评估。本研究旨在探究血管造影病变形态学特征能否为未筛选人群中预测心肌缺血的QFR应用提供增量价值。
研究方法：本研究为CT-血流储备分数（CT-FFR）CHINA临床试验的亚组研究，纳入5家中心共345名因疑似冠状动脉疾病接受冠状动脉CT血管造影（CTA）后需行诊断性有创冠状动脉造影（ICA）的受试者。对直径狭窄30%~90%的所有血管测量血流储备分数（fractional flow reserve, FFR）。以盲法对159名受试者的186处病变计算QFR。此外，记录或测量病变特征参数，包括左前降支（left anterior descending artery, LAD）受累病变、狭窄病变处分支血管（BL）、多支病变（ML）、最小管腔直径（MLD）、参考管腔直径（RLD）、直径狭窄百分比（%DS）、病变长度（LL）及LL/MLD4。采用logistic回归构建两类模型：将单个或两个病变参数与QFR联合，并在血管水平比较各模型与单独QFR的诊断性能。
研究结果：最终共纳入148名受试者（平均年龄59.5岁；男性101名），共计175支冠状动脉纳入最终分析。总计81支（46%）血管被判定为血流动力学显著病变。以FFR界值0.80作为参考标准，QFR对血管的正确分类率为82.29%。QFR的受试者工作特征曲线下面积（AUC）为0.86，灵敏度、特异度、阳性预测值及阴性预测值分别为80.25%、84.04%、81.25%及83.16%。联合模型（QFR+LAD+MLD、QFR+LAD+%DS、QFR+BL+MLD及QFR+BL+%DS）的AUC更高（分别为0.91 vs 0.86，P=0.02；0.91 vs 0.86，P=0.02；0.91 vs 0.86，P=0.02；0.90 vs 0.86，P=0.03），性能优于单独QFR。与单独QFR相比，联合模型（QFR+BL及QFR+MLD）的灵敏度得到提升（分别为91.36% vs 80.25%，91.36% vs 80.25%，均P<0.05），且未降低特异度与准确度。
研究结论：联合血管造影病变参数可优化QFR在未筛选人群中预测心肌缺血的效能。