OBJECTIVES The aim of this study was to evaluate the diagnostic accuracy of stress myocardial blood flow ratio (SFR), a novel parameter derived from stress dynamic computed tomographic perfusion (CTP), for the detection of hemodynamically significant coronary stenosis. BACKGROUND A comprehensive cardiac computed tomographic protocol combining coronary computed tomographic angiography (CTA) and CTP can provide a simultaneous assessment of both coronary artery anatomy and ischemia. METHODS Patients with chest pain scheduled for invasive angiography were prospectively enrolled in this study. Stress dynamic CTP was performed followed by coronary CTA using a second-generation dual-source computed tomographic system. At subsequent invasive angiography, fractional flow reserve was performed to identify hemodynamically significant stenosis. For each coronary territory, SFR was defined as the ratio of hyperemic myocardial blood flow (MBF) in an artery with stenosis to hyperemic MBF in a nondiseased artery. The diagnostic accuracy of SFR to identify hemodynamically significant stenosis was determined against the reference standard of invasive fractional flow reserve ≤0.80. RESULTS A total of 82 patients (mean age 58.5 ± 10 years) with 101 vessels with either 1- or 2-vessel disease were included. By FFR, 48 (47.5%) vessels were deemed hemodynamically significant. Hyperemic MBF and SFR were lower for vessels with hemodynamically significant lesions (95.1 ± 32.4 min/100 ml/min vs. 142.5 ± 31.2 min/100 ml/min and 0.66 ± 0.14 vs. 0.90 ± 0.07, respectively; p < 0.01 for both). When compared with ≥50% stenosis by CTA, the specificity for detecting ischemia by SFR increased from 43% to 91%, while the sensitivity decreased from 95% to 62%. Accordingly, the positive and negative predictive values were 85% and 73%, respectively. The combination of stenosis ≥50% by CTA and SFR resulted in an area under the curve of 0.91, which was significantly higher compared with hyperemic MBF (area under the curve = 0.79; p = 0.013). CONCLUSIONS Calculation of SFR by dynamic CTP provides a novel and accurate method to identify flow-limiting coronary stenosis.

中文翻译：

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通过动态CT灌注获得的应激性心肌血流比率可识别血液动力学上显着的CAD。

目的本研究的目的是评估应力心肌血流比率（SFR）的诊断准确性，应力心肌血流比率（SFR）是从应力动态计算机断层扫描灌注（CTP）获得的新参数，用于检测血液动力学显着的冠状动脉狭窄。背景技术结合冠状动脉计算机断层摄影血管造影术（CTA）和CTP的全面的心脏计算机断层摄影方案可以提供对冠状动脉解剖结构和局部缺血的同时评估。方法前瞻性纳入计划进行有创血管造影的胸痛患者。使用第二代双源计算机断层扫描系统进行应力动态CTP，然后进行冠状动脉CTA。在随后的有创血管造影术中，进行了部分血流储备以识别血液动力学上显着的狭窄。对于每个冠状动脉区域，SFR定义为狭窄动脉中的充血性心肌血流量（MBF）与未患病动脉中的充血性MBF之比。SFR在确定血流动力学显着狭窄方面的诊断准确度是根据侵入性部分流量储备≤0.80的参考标准确定的。结果共纳入82例患者（平均年龄58.5±10岁），其中101例血管患有1或2血管疾病。通过FFR，认为48个（47.5％）血管具有血流动力学显着性。具有血流动力学显着性病变的血管的充血MBF和SFR较低（分别为95.1±32.4 min / 100 ml / min和142.5±31.2 min / 100 ml / min和0.66±0.14 vs.0.90±0.07;两者均p <0.01 ）。与CTA≥50％的狭窄相比，SFR检测局部缺血的特异性从43％提高到91％，而敏感性从95％降低到62％。因此，阳性和阴性预测值分别为85％和73％。CTA和SFR合并狭窄≥50％时，曲线下面积为0.91，比充血MBF高得多（曲线下面积= 0.79； p = 0.013）。结论通过动态CTP计算SFR提供了一种新颖且准确的方法来识别限流性冠状动脉狭窄。p = 0.013）。结论通过动态CTP计算SFR提供了一种新颖且准确的方法来识别限流性冠状动脉狭窄。p = 0.013）。结论通过动态CTP计算SFR提供了一种新颖且准确的方法来识别限流性冠状动脉狭窄。