Fractional Flow Reserve Measurement by Coronary Computed Tomography Angiography:A Review with Future Directions

Invasive fractional fl ow reserve(FFR)measurement is currently the gold standard for coronary intervention.FFR measurement by coronary computed tomography angiography(FFRCT)is a novel and promising imaging technology that permits noninvasive assessment of physiologically signifi cant coronary lesions.FFRCT is capable of combining the anatomic information provided by coronary computed tomography angiography with computational fl uid dynamics to compute FFR.To date,several studies have reported the diagnostic performance of FFRCT compared with invasive FFR measurement as the reference standard.Further studies are now being implemented to determine the clinical feasibility and economic implications of FFRCT techniques.This article provides an overview and discusses the available evidence as well as potential future directions of FFRCT.

Diagnostic accuracy of a deep learning approach to calculate FFR from coronary CT angiography

Background The computational fluid dynamics(CFD)approach has been frequently applied to compute the fractional flow reserve(FFR)using computed tomography angiography(CTA).This technique is efficient.We developed the DEEPVESSEL-FFR platform using the emerging deep learning technique to calculate the FFR value out of CTA images in five minutes.This study is to evaluate the DEEPVESSEL-FFR platform using the emerging deep learning technique to calculate the FFR value from CTA images as an efficient method.Methods A single-center,prospective study was conducted and 63 patients were enrolled for the evaluation of the diagnostic performance of DEEPVESSEL-FFR.Automatic quantification method for the three-dimensional coronary arterial geometry and the deep learning based prediction of FFR were developed to assess the ischemic risk of the stenotic coronary arteries.Diagnostic performance of the DEEPVESSEL-FFR was assessed by using wire-based FFR as reference standard.The primary evaluation factor was defined by using the area under receiver-operation characteristics curve(AUC)analysis.Results For per-patient level,taking the cut-off value<0.8 referring to the FFR measurement,DEEPVESSEL-FFR presented higher diagnostic performance in determining ischemia-related lesions with area under the curve of 0.928 compare to CTA stenotic severity 0.664.DEEPVESSEL-FFR correlated with FFR(R=0.686,P<0.001),with a mean di&ference of-0.006士0.0091(P=0.619).The secondary evaluation factors,indicating per vessel accuracy,sensitivity,specificity,positive predictive value,and negative predictive value were 87.3%,97.14%,75%,82.93%,and 95.45%,respectively.Conclusion DEEPVESSEL-FFR is a novel method that allows efficient assessment of the functional significance of coronary stenosis.

Novel Approaches for the Use of Cardiac/Coronary Computed Tomography Angiography

Recent developments in the novel imaging technology of cardiac computed tomography(CT)not only permit detailed assessment of cardiac anatomy but also provide insight into cardiovascular physiology.Foremost,coronary CT angiography(CCTA)enables direct noninvasive examination of both coronary artery stenoses and atherosclerotic plaque characteristics.Calculation of computational fl uid dynamics by cardiac CT allows the noninvasive estimation of fractional fl ow reserve,which increases the diagnostic accuracy for detection of hemodynamically signifi cant coronary artery disease.In addition,a combination of myocardial CT perfusion and CCTA can provide simultaneous anatomical and functional assessment of coronary artery disease.Finally,detailed anatomical evaluation of atrial,ventricular,and valvular anatomy provides diagnostic information and guidance for procedural planning,such as for transcatheter aortic valve replacement.The clinical applications of cardiac CT will be extended with the development of these novel modalities.

Simplified Bernoulli Formula to Diagnose Ischemia-Causing Stenosis at Coronary CT Angiography: Comparison with SPECT

Purpose: To compare the diagnostic performance of estimated energy loss (EEL) calculated using a simplified Bernoulli formula at coronary computed tomography (CT) and single photon emission computed tomography (SPECT) to diagnose ischemia-causing stenosis by invasive fractional flow reserve (FFR). Methods: We retrospectively included 43 patients who underwent coronary CT, SPECT, and FFR measurement by catheter within 3 months. When an intermediate stenosis (40% - 70%) was present at CT, EEL was calculated using the following parameters: lesion length, diameter stenosis, minimal lumen area, and the myocardial volume. An EEL > 1.17 or diameter stenosis > 70% was determined ischemic. Stress-induced ischemia by SPECT was determined when a perfusion defect at stress was accompanied with a fill-in at rest. An FFR ≤ 0.80 or diameter stenosis >70 % was determined as ischemic by catheter. Results: A total of 26 vessels were determined as ischemic by catheter exam. The per-vessel sensitivity and specificity of EEL and SPECT were 81% vs 42% and 92% vs 91%, respectively. The accuracy of EEL to diagnose stenosis causing ischemia was significantly higher than SPECT (90% vs 81%, p = 0.04). The area under the curve of the receiver operating characteristics curve was also significantly higher for EEL than SPECT (0.86 vs 0.67, p Conclusions: EEL showed higher accuracy than SPECT to diagnose ischemia-causing stenosis by improving the sensitivity.

Instantaneous wave-free ratio(iFR) to determine hemodynamically significant coronary stenosis: A comprehensive review

Coronary angiography is considered to be the gold standard in the morphological evaluation of coronary artery stenosis. The morphological assessment of the severity of a coronary lesion is very subjective. Thus, the invasive fractional flow reserve(FFR) measurement represents the current standard for estimation of the hemodynamic significance of coronary artery stenosis. The FFR-guided revascularization strategy was initially classified as a Class-IA-recommendation in the 2014 European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on myocardial revascularization. Both the Deferral vs Performance of Percutaneous Coronary Intervention of Functionally Non-Significant Coronary Stenosis and Flow Reserve vs Angiography for Multivessel Evaluation studies showed no treatment advantage for hemodynamically insignificant stenoses. With the help of FFR(and targeted interventions), clinical results could be improved; however, the use in clinical practice is still limited due to the need of adenosine administration and a significant prolongation of the length of the procedure. Instantaneous wave-free ratio(iFR~) is a new innovative approach for the determination of the hemodynamic significance of coronary stenosis, which can be obtained at rest without the use of vasodilators. Regarding the periprocedural complications as well as prognosis, iFR~ showed non-inferiority to FFR in the SWEDEHEART and DEFINE-FLAIR trials. Furthermore, iFR~, enhanced by iFR~-pullback, provides the possibility to display the iFR~-change over the course of the vessel to create a hemodynamic map.

Factors influencing the functional significance in intermediate coronary stenosis

Objective To analyze the influencing factors of the functional significance determined by fractional flow reserve （FFR） in interme- diate coronary artery stenosis. Methods The study enrolled 143 patients with 203 intermediate coronary lesions. Pressure-derived FFR of these lesions was gained at maximal hyperemia induced by intravenous adenosine infusion. An FFR 〈 0.80 was considered as abnormal functional significance. Anatomic parameters at the lesion sites were obtained by off-line quantitative coronary angiography analysis （QCA）. The predictive value of the demographic characteristics and anatomic parameters for FFR in these intermediate lesions was assessed using multiple linear and binary logistic regression analysis. Results Overall, FFR 〈 0.8 was found in 70 （34%） of the total 203 intermediate coronary lesions. FFR values were positively correlated with QCA-measured minimum lumen diameters （MLD, r = 0.372, P = 0.000） and the reference vessel diameters （RVD, r = 0.217, P〈 0.002） were negatively correlated with percent area stenosis （AS, r = -0.251, P = 0.000） and percent diameter stenosis （DS, r = -0.210, P = 0.000）. Age, MLD and the lesion location in different coronary arteries were the inde- pendent determinants of FFR 〈 0.8. Conclusions MLD can predict the functional significance of intermediate coronary stenosis, while age and the lesion location in different coronary arteries should be taken into account as important influencing factors of FFR values.

A Case of Local Groin Abscess Caused by Transfemoral Coronary Procedures

Bacterial infection due to coronary angiography is an uncommon but important complication of percutaneous coronary intervention (PCI) which is responsible for significant morbidity and extended hospital stay. The reasons for this symptom are still unclear. We report a case of local groin abscess two weeks after the latest procedure. The reasons responsible for the groin abscess in this case might be diabetes mellitus without being properly controlled, left ventricular (LV) systolic dysfunction, multiple operations in the same site, the usage of vascular closure device (VCD), and long time pressure after the procedure. We should pay enough attention to these risk factors in the future clinical practice to avoid this serious complication.

基于Revolution CT的冠状动脉血管成像联合血流储备分数评估冠心病并发心力衰竭患者NYHA心功能分级及预后的效果

目的探究基于Revolution计算机断层扫描(computed tomography,CT)的冠状动脉血管成像(coronary CT angiography,CCTA)联合血流储备分数(fractional flow reserve,FFR)对冠状动脉粥样硬化性心脏病(冠心病)并发心力衰竭患者纽约心脏协会(New York Heart Association,NYHA)心功能分级及预后的评估效果。方法采取回顾性分析方法,收集青岛阜外心血管病医院2021年4月至2022年4月收治的64例冠心病并发心力衰竭患者的病历资料,统计患者基于Revolution CT技术的CCTA联合FFR的检查结果,比较不同NYHA心功能分级患者CCTA定量系数和CT-FFR指标,并进行CCTA定量系数联合CT-FFR与NYHA心功能分级的相关性分析。随访发生主要心血管不良事件(major adverse cardiovascular events,MACE)的患者例数,对发生MACE的危险因素进行Cox多因素回归分析。得出单独FFR和单独CCTA检查以及联合检查的受试者工作特征曲线(receiver operating characteristic curve,ROC)-曲线下面积(area under the curve,AUC)。结果NYHA心功能分级Ⅲ级患者斑块数、血管体积、斑块体积、血管狭窄程度、斑块负荷、重建指数、CT-FFR值大于Ⅰ级患者,差异有统计学意义(P<0.05)。斑块数、血管体积、斑块体积、血管狭窄程度、斑块负荷、重建指数以及CT-FFR与NYHA心功能分级呈正相关(P<0.05)。MACE组患者CT-FFR≤0.80、重度狭窄的比例高于非MACE组,差异有统计学意义(P<0.05)。左心室射血分数、冠状动脉狭小程度及CT-FFR是发生MACE的独立危险因素;基于Revolution CT技术的CCTA联合FFR检查的ACU大于单独CCTA检查和FFR检查(P<0.05)。结论针对冠心病并发心力衰竭患者,基于Revolution CT技术的CCTA联合FFR对判断冠心病并发心力衰竭患者NYHA心功能分级和预后有较高价值。

基于CCTA的ΔCT-FFR对重度钙化冠状动脉功能学评估的临床价值分析

目的探讨基于冠状动脉计算机断层扫描血管成像(CCTA)的血流储备分数(CT-FFR)和冠状动脉病变最严重狭窄处的近端与远端CT-FFR测量差值(ΔCT-FFR)对重度钙化冠状动脉功能学评估诊断效能的临床价值。方法收集2018年1月-2019年6月解放军总医院心血管内科收治住院的107例冠心病(CAD)患者的149支血管进行回顾性分析。所有患者住院期间依次进行CCTA、CT-FFR、侵入性冠状动脉造影(ICA)和有创血流储备分数(FFR)检查。以单支冠状动脉钙化积分(CACS)≥100判断为血管水平的重度钙化,根据CACS水平将冠状动脉分为CACS≥100组(n=56)和CACS<100组(n=93)。以FFR≤0.8作为诊断冠状动脉血流动力学异常的“金标准”,ΔCT-FFR定义为冠状动脉病变最严重狭窄处近端与远端CTFFR的测量差值。采用Pearson相关和Bland-Altman图评估血管水平CT-FFR与FFR值的相关性和一致性。通过ΔCT-FFR校正CT-FFR的检测结果,使用Delong检验比较不同诊断方法间受试者工作特征曲线(ROC)的曲线下面积(AUC),在血管水平分析其对重度钙化冠状动脉功能学评估诊断效能的增量价值。结果在血管水平CT-FFR与FFR值具有较好的相关性(CACS≥100组:r=0.71,P<0.01;CACS<100组:r=0.73,P<0.01)和一致性(CACS≥100组:Mean=-0.01,P=0.25;CACS<100组:Mean=0,P=0.96)。与CACS<100组比较,CACS≥100组FFR(0.80±0.08 vs.0.84±0.09,P=0.004)和CT-FFR值(0.81±0.06 vs.0.85±0.06,P<0.001)明显降低,ΔCT-FFR值(0.14±0.06 vs.0.09±0.06,P<0.001)明显增高。与CACS<100组比较,CACS≥100组CT-FFR的诊断效能明显下降[(AUC=0.792,95%CI 0.663~0.889)vs.(AUC=0.929,95%CI 0.856~0.972),P=0.04]。经ΔCT-FFR校正诊断后,CACS≥100组CT-FFR的诊断效能较前明显提高[(AUC=0.876,95%CI 0.760~0.949)vs.(AUC=0.792,95%CI0.663~0.889),P=0.02],与CACS<100组差异无统计学意义(P=0.37)。结论对于重度钙化冠状动脉,经ΔCT-FFR校正后,CT-FFR评估冠状动脉功能学的诊断效能明显提高。

定量血流分数和血流储备分数的诊断一致性和影响因素

目的探讨血流储备分数(FFR)和定量血流分数(QFR)诊断一致性以及影响二者诊断一致性病变的特征。方法回顾分析2019年1月至2021年12月就诊于北京大学第三医院心内科冠状动脉造影狭窄30%~70%并接受FFR检测的非急性心肌梗死患者。以FFR或QFR≤0.80为阳性(+),>0.80为阴性(–),将患者分为:诊断一致组(FFR+/QFR+和FFR–/QFR–)、诊断不一致组(FFR+/QFR–和FFR–/QFR+),以FFR为金标准,分析QFR的诊断价值,比较各组之间临床特征及病变特征之间的差异。结果共纳入236例患者,平均年龄(64.48±9.63)岁,男67.8%。QFR和FFR诊断一致性为184例(78.0%),Person相关系数为0.557(P<0.001)。在FFR+患者中,诊断不一致组中最小管腔直径更大[(1.56±0.34)mm比(1.39±0.31)mm,P=0.019]、病变长度更短[(21.37±11.73)mm比(36.86±18.09)mm,P<0.001]、冠状动脉造影衍生的微循环阻力指数(AMR)更高[(277.50±28.87)mmHg·s/m比(178.02±49.13)mmHg·s/m,P<0.001]。通过二元Logistic回归分析提示AMR[OR0.93,95%CI0.88~0.99,P=0.030]和病变长度[OR 1.27,95%CI 1.01~1.60,P=0.045]是诊断不一致独立预测因子。在FFR–组中,诊断不一致组的病变长度更长[(33.08±16.05)mm比(21.40±13.36)mm,P=0.020],AMR[(169.66±24.01)mmHg·s/m比(265.95±44.78)mmHg·s/m,P<0.001]和低密度脂蛋白胆固醇[1.57(1.10,1.97)mmol/L比2.15(1.79,2.74)mmol/L,P=0.031]更低。二元Logistic回归分析未发现具有统计学意义变量。结论QFR和FFR具有较高的诊断一致性。在FFR+患者中,AMR和病变长度可能影响QFR和FFR的诊断一致性。

冠脉CT血管造影斑块人工智能定量参数与血流储备分数的关系

目的 探讨冠脉CT血管造影(CCTA)斑块人工智能(AI)定量参数与CT血流储备分数(FFR-CT)的相关性。方法 收集怀疑冠心病患者共84例,男52例,女32例,年龄27~81岁,平均(58.1±11.9)岁,均行CCTA检查。将图像传输至数坤软件并对冠脉血管标记、斑块分析、计算相应FFR-CT值。斑块AI参数包括长度、体积、最小管腔面积(MLA)、最狭窄程度(MLD)、脂类体积及占比、纤维脂类体积及占比、纤维体积及占比、钙化体积及占比。FFR-CT≤0.8定义为可能存在血流动力学异常或心肌缺血。评估斑块参数与FFR-CT相关性,采用二元logistic回归筛选冠脉血流储备异常(FFR-CT≤0.8)的独立危险因素,采用ROC曲线及曲线下面积(AUC)评价其诊断效能,计算灵敏度、特异度及模型预测准确率。结果 84例患者主要症状为胸痛(39例,占46.4%)与胸闷(27例,占32.1%)。Spearman相关分析结果显示FFR-CT与MLA呈正相关(r=0.49,P <0.000 1),与长度、体积、脂类体积、纤维脂类体积、纤维体积及钙化体积呈负相关(r=-0.44、-0.56、-0.40、-0.36、-0.42、-0.40,P <0.05),其中与MLD呈中等程度负相关(r=-0.60,P <0.000 1)。单因素logistic回归分析结果显示斑块长度、体积、MLA、MLD、脂类体积、纤维脂肪体积、纤维体积、钙化体积等参数是FFR-CT≤0.8的独立危险因素(P <0.05)。经调整后的多因素logistic回归分析结果显示,MLD是FFR≤0.8的独立危险因素(OR=1.082,95%CI:1.034~1.133,P=0.001),预测模型为logit(P)=0.079X1-4.052,X1为MLD值,预测准确率为85.2%。斑块长度、MLD、脂类体积、纤维体积及钙化体积诊断冠脉血流动力学异常(FFR-CT≤0.8)的AUC分别为0.796、0.886、0.711、0.754、0.698,灵敏度与特异度分别为47.83%、73.91%、73.90%、52.17%、60.87%与92.11%、73.68%、60.53%、84.21%、89.47%,5种指标联合诊断的AUC为0.906,灵敏度与特异度为73.91%、71.05%。结论 冠脉斑块AI参数与FFR-CT存在不同程度相关性,MLD是FFR-CT≤0.8的独立危险因素,具有较高的诊断效能。

冠状动脉CT血流储备分数在冠心病PCI术前的应用

目的探讨冠状动脉CT血流储备分数在冠心病冠状动脉成形术(PCI)前的应用。方法选取63例患者冠状动脉CT检查和侵入性冠状动脉造影的影像资料,采用基于深度学习技术的软件进行CT血流储备分数分析,根据是否进行支架治疗分为PCI组和非PCI组,分析比较两组冠状动脉狭窄率及CT血流储备分数。结果冠状动脉PCI组患者斑块处管腔较非PCI组狭窄,狭窄远端CT血流储备分数亦低于非PCI组,差异有统计学意义(P<0.05)。结论CT血流储备分数能无创、快速、准确的“一站式”对冠状动脉病变进行解剖学和功能学评估,拓展了CT检查对冠状动脉病变的运用,提高了冠心病需要介入治疗的检出率,有重要的临床意义及广阔的应用前景。

血管内超声测定定量血流分数对临界病变冠状动脉介入手术策略的价值

目的结合血管内超声结果分析定量血流分数在评估冠状动脉中重度狭窄及介入手术策略的指导价值。方法回顾性收集2022年2—10月在北京安贞医院住院行冠状动脉造影(CA)和/或经皮冠状动脉介入治疗(PCI)并接受靶血管血管内超声检查(IVUS)的患者110例,基于IVUS结果定量测定靶血管最小管腔面积(MLA)和斑块负荷(PB)等参数。利用患者的冠状动脉造影图像数据,对接受治疗的靶病变血管计算定量血流分数(QFR)。以IVUS结果为依据,评价QFR对血管病变程度的诊断及对行介入手术策略的价值。结果筛选临界病变并行IVUS检查110例,其中IVUS图像伪影严重13例,血管严重迂曲18例,造影显示全程病变或图像质量不佳24例,最终共计入组患者55例、靶血管55支。以IVUS管腔面积≤3 mm^(2)或IVUS管腔面积≤4 mm^(2)并且IVUS斑块负荷≥70%,作为血管显著狭窄引起心肌缺血的诊断标准。患者QFR值为0.75±0.12,MLA为(3.32±0.74)mm^(2),PB为(70±9)%。QFR值≤0.800时与IVUS评价冠状动脉狭窄缺血的一致性良好(Kappa=0.656,P<0.01,95%CI 0.452~0.860)。QFR的敏感度为0.853,特异度为0.810,阳性预测值为87.9%,阴性预测值为77.3%;MLA和QFR值之间存在中度正相关关系(r=0.566,P<0.01)。PB和QFR值之间存在轻度负相关关系(r=-0.371,P<0.01)。结论QFR对冠脉临界病变狭窄治疗决策的指导具有良好的诊断意义。

冠状动脉树重建扩大到较小动脉提高FFRCT准确性的研究

目的本研究旨在通过在计算流体动力学(CFD)领域扩展冠脉树来提高基于冠状动脉CT血管成像(coronary CT angiography,CCTA)的血流储备分数(FFR)的准确性。进行了一项观察性研究,以评估将冠状动脉树分析从最小直径1.2mm扩展到0.8 mm的效果。方法对接受CCTA和介入性FFR治疗的患者进行回顾性研究。76名患者符合纳入标准。重建三维冠状动脉树,生成具有不同管腔直径下限(1.2 mm和0.8 mm)的有限元网格。根据Murray定律定义了出口边界条件。应用NKS方法求解CFD控制方程,得到FFRCT。结果在个体患者水平上,将冠状动脉树的最小直径从1.2mm扩大到0.8mm,FFRCT的灵敏度提高了16.7%(P=0.022),这导致四个假阴性病例转变为真阳性病例。ROC曲线的AUC值由0.74增至0.83。此外,NKS方法可以解决在2160个处理器核的情况下,在10.5分钟内将冠状动脉树扩展到0.8 mm管腔直径的计算问题。结论将重建的冠脉扩大到较小的管腔直径可以显著提高FFRCT的敏感性,NKS方法可以为未来的临床应用提供良好的计算时间。

冠脉造影联合血流储备分数在评估经皮冠状动脉介入术中的价值

目的:探究冠脉造影联合血流储备分数(fractional flow reserve,FFR)在评估经皮冠状动脉介入术(percutaneous coronary intervention,PCI)中的临床应用价值。方法:选择2021年5月—2022年8月丰城市人民医院收治的120例冠心病患者,随机分为对照组和观察组,各60例。对照组接受冠状动脉造影及PCI治疗,观察组在对照组基础上联合FFR诊断,依据FFR结果判定PCI方式。对比两组支架置入数量、不良心血管事件发生率、心功能、6 min步行距离(6-minute walking distance,6MWD)、西雅图心绞痛量表(Seattle angina questionnaire,SAQ)评分。结果:观察组支架置入数量较对照组明显少,差异有统计学意义(P<0.05)。观察组不良心血管事件发生率低于对照组,差异有统计学意义(P<0.05)。治疗前,两组心功能、6MWD、SAQ评分对比,差异均无统计学意义(P>0.05);治疗后,观察组心功能、6MWD、SAQ评分均优于对照组,差异均有统计学意义(P<0.05)。结论:冠脉造影联合FFR,对PCI术的方式具有显著的评估价值,提高临床治疗准确性和有效性。

冠状动脉CT血管成像联合CT-FFR对冠心病心肌缺血影响因素的研究

目的应用冠状动脉CT血管成像(coronary CT angiography,CCTA)联合冠状动脉CT血流储备分数(coronary CT angiography derived fractional flow reserve,CT-FFR)探讨冠心病患者心肌缺血的影像学特征,并探讨冠心病患者心肌缺血的影响因素。方法回顾性选取2023年1月至11月于浙江中医药大学附属杭州市中医院就诊并行CCTA检查的86例患者,根据测量的CT-FFR值将其分为缺血组(CT-FFR≤0.80,45例)与非缺血组(CT-FFR>0.80,41例),比较两组患者的斑块特征,采用多因素Logistic回归分析探讨冠心病患者心肌缺血的影响因素。结果缺血组患者的糖尿病占比显著高于非缺血组(P<0.05)。共有150支冠状动脉显示有斑块,斑块最常见部位为左前降支(114个)。对212个斑块进行分析,其中缺血组68个斑块,非缺血组144个斑块。非缺血组钙化斑块占比显著高于缺血组(P<0.05);缺血组管腔狭窄程度、斑块体积、脂类成分占比、纤维脂类成分体积均显著大于非缺血组,斑块纤维成分体积显著小于非缺血组(P<0.05)。多因素Logistic回归分析结果显示,管腔狭窄程度(OR=1.054,P=0.026)和斑块体积(OR=1.027,P=0.048)均是冠心病患者心肌缺血的的影响因素。结论管腔狭窄程度及斑块体积均是冠心病患者心肌缺血的影响因素,可对此类患者进行针对性的治疗。

人工智能诊断系统及CT无创血流储备分数在评估高海拔地区 冠脉临界病变中的应用

目的探讨基于冠状动脉CT血管成像(CCTA)的人工智能(AI)诊断系统及CT无创血流储备分数(CT-FFR)在评估高海拔地区冠状动脉临界病变结构及功能学中的应用价值。方法前瞻性收集2022年1月~2023年10月青海大学附属医院冠心病临界病变患者164例,按居住地海拔进行分组,其中2000~3000m为A组(n=83),3000m以上为B组(n=81),再将两组患者按冠脉狭窄程度细分为50%~60%亚组(n=84)和61%~70%亚组(n=80)。将患者冠状动脉CT血管成像数据导入AI辅助诊断及CT-FFR测量系统,以冠脉造影及冠脉传统血流储备分数(FFR)为金标准,分别评价AI及CT-FFR在高海拔地区冠脉临界病变诊断中的应用。结果以FFR为金标准,CT-FFR与FFR的一致性为83.75%。B组钙化斑块、易损斑块高于A组(P=0.037、0.020);B组冠状动脉多支病变、61%~70%狭窄程度发生率均高于A组(P<0.05);A组、B组在61%~70%亚组钙化斑块、易损斑块发生率均高于50%~60%亚组(P<0.05)。B组CT-FFR值低于A组(0.76±0.04 vs 0.88±0.05,P<0.01);A、B两组在61%~70%亚组CT-FFR值≤0.80、<0.70的发生率高于50%~60%亚组(P<0.05)。结论AI诊断系统及CT-FFR对评估高海拔地区冠状动脉临界病变的结构特征及血流动力学改变的结果与冠脉造影、FFR一致性高,具有较高的诊断敏感度和特异度。

CCTA-AI联合FFR-CT诊断冠状动脉狭窄病变的应用价值研究

目的评估计算机断层扫描血管成像(CCTA)与人工智能(AI)联合心肌灌注分数(FFR-CT)对冠状动脉狭窄病变的诊断价值。方法选择于2022年1月至2023年2月到南阳市中心医院接受诊治的80例疑似冠状动脉狭窄病变患者作为观察对象。所有患者均接受CCTA以及冠状动脉造影(CAG)检查,其检查的间隔时间应在14天内,然后通过AI软件自动对CCTA的图像进行重建和计算,同时计算FFR-CT的数值。计算人工智能辅助的心脏计算机断层扫描(CCTA-AI)联合FFR-CT诊断的敏感度、特异度、准确度、阳性预测值和阴性预测值。结果80例患者经CAG检查确诊,72例患者为冠状动脉狭窄病变,占比为90%;8例患者为非冠状动脉狭窄病变,占比为10%。CCTA-AI联合FFR-CT检查的敏感度、特异度、阳性预测值、阴性预测值、准确度以及AUC值均高于CCTA-AI、FFR-CT单独检查,差异有统计学意义(P<0.05)。结论采用CCTA-AI联合FFR-CT检查诊断冠状动脉狭窄病变具有较高的诊断效能,其敏感度及特异度均得到显著提高。

冠状动脉CT血管成像衍生的血流储备分数对冠状动脉狭窄的诊断效能分析

目的探讨冠状动脉(下称冠脉)CT血管成像(CTA)衍生的血流储备分数(FFRCT)对冠脉狭窄的诊断效能。方法回顾性选择2021年1月至2022年1月在丽水市人民医院行冠脉CTA且经过冠脉造影检查的患者108例。根据冠脉狭窄情况,分为冠脉狭窄(狭窄率≥50%,观察组)95例和非冠脉狭窄(狭窄率<50%,对照组)13例。比较两组患者一般资料、FFRCT值。分析FFRCT值与冠脉狭窄程度的相关性,绘制ROC曲线,评估FFRCT在冠脉狭窄中的诊断效能。结果观察组FFRCT值为(0.81±0.10),低于对照组的(0.88±0.12),差异有统计学意义(P=0.023)。FFRCT值与冠脉狭窄程度呈负相关(r=-0.420,P<0.05)。FFRCT诊断冠脉狭窄的AUC为0.748,其诊断冠脉狭窄的灵敏度和特异度分别为0.78和0.62。结论在诊断冠脉狭窄上FFRCT与CTA存在低中度相关。

基于冠状动脉CT血流储备分数预测冠心病价值的研究

目的 探究冠状动脉CT血流储备分数(fractional flow reserve derived from coronary computed tomography, FFR_(CT))对冠心病的预测价值。方法 回顾性连续收集2020年1月至2022年2月于苏北人民医院就诊的疑似冠心病患者136例共309支主要冠状动脉血管。患者已完成冠状动脉CT血管造影(coronary computed tomography angiography, CCTA)、FFR_(CT)和冠状动脉造影术(coronary angiography, CAG)检查。比较CCTA和FFR_(CT)对309支冠状动脉主要血管狭窄诊断的准确性、阳性预测值、阴性预测值、敏感性、特异性;采用一致性检验分析FFR_(CT)与CAG的相关性;影像科医师对其中156支血管测量影像学参数,记录并分析最窄管腔直径、狭窄斑块长度、直径狭窄率、面积狭窄率、狭窄管腔面积与斑块性质。将冠状动脉血管狭窄≥50%的98支血管列入冠心病组,<50%排除缺血性狭窄的58支血管列入非冠心病组。用logistic回归分析156支血管的相关参数与冠心病的关系;用ROC曲线分析各参数的单独及联合诊断冠心病的价值。结果 FFR_(CT)诊断冠心病的准确性高于CCTA(P<0.01)。Kappa一致性分析显示,FFR_(CT)诊断结果与CAG诊断结果的Kappa值为0.620,具有较高的一致性(P<0.01)。冠心病组管腔最窄直径、FFR_(CT)明显小于非冠心病组,狭窄斑块长度、直径狭窄率、面积狭窄率明显大于非冠心病组(P<0.01)。多因素logistic回归分析显示,管腔最窄直径(OR=0.536,95%CI:0.335~0.858)、狭窄斑块长度(OR=1.109,95%CI:1.054~1.166)、FFR_(CT)≤0.80(OR=0.204,95%CI:0.078~0.532)是预测冠心病的独立影响因素(P<0.01)。ROC曲线显示,管腔最窄直径、狭窄斑块长度、FFR_(CT)≤0.80三者联合诊断冠心病的曲线下面积为0.853(0.795~0.918)。结论 FFR_(CT)相较CCTA诊断冠心病具有较高的价值,FFR_(CT)≤0.8、管腔最窄直径、狭窄斑块长度三者联合诊断能进一步提高诊断冠心病的准确性。