angiography based simulation of FFR

冠状动脉粥样硬化是西方世界发病率和死亡率的主要原因之一。临床表现从运动时稳定的心绞痛到心肌梗死和心源性猝死。在急性冠状动脉综合征之外，通常需要心肌缺血的证据来确定冠状动脉狭窄的血运重建术的指征。为此目的使用了各种压力测试或检查。然而，尽管有这一建议，超过40%的冠状动脉造影是在没有缺血无创证据的稳定患者中进行的。在没有无创缺血证据或缺血与冠状动脉狭窄之间的关系不明确的情况下，有创冠状动脉造影提供了确定“分数血流储备”（FFR）的可能性，以获得有关冠状动脉狭窄血流动力学相关性的信息。在该方法中，冠状动脉造影时，将一根极细的导线尖端携带压力传感器插入冠状动脉，在药理学上实现血管扩张后，通常使用腺苷比较冠状动脉狭窄上游和下游的血压。如果狭窄后与狭窄前血压的比值≤0.8，则存在血流动力学相关性，患者可从血运重建中获益。基于令人信服的研究证据，FFR测量被欧洲心脏病学会列为评估冠状动脉狭窄治疗需要的IA级推荐。近年来，有创冠状动脉造影术仅能显示血管腔的解剖结构，研究人员一直在努力获取有关冠脉狭窄的血流动力学相关信息。使用不同的方法方法，一些研究表明，分数血流储备可以模拟或计算基于有创冠状动脉造影。本项目的目的是科学评价基于血管造影的血流储备（FFRangio）模拟，以促进该方法的临床验证，确定影响诊断有效性的因素，并使该方法的进一步发展。新方法，如本文介绍的FFRangio，必须产生可靠的结果，才能广泛应用于临床实践。因此，我们将系统评估以下参数对FFRangio预后的影响以及FFRangio与已建立的有创FFR的相关性：心相e2的影响。帧率的影响狭窄定位的影响inter-operator variability5。FFRangio与冠状动脉CT血管造影数据集模拟FFR的比较。FFRangio与其他评估冠状动脉狭窄严重程度的有创参数如pd/pa、iFR、RFR的比较。

Atherosclerosis of the coronary arteries is one of the leading causes of morbidity and mortality in the Western world. The clinical presentation ranges from stable angina on exertion to myocardial infarction and sudden cardiac death. Outside of acute coronary syndrome, evidence of myocardial ischemia is generally required to establish the indication for revascularization of coronary stenosis. Various stress tests or examinations are used for this purpose. However, despite this recommendation, more than 40% of coronary angiographies are performed in stable patients without prior noninvasive evidence of ischemia. In the absence of noninvasive evidence of ischemia or if the association between ischemia and coronary stenosis is not clear, invasive coronary angiography offers the possibility to determine the "fractional flow reserve" (FFR) to obtain information about the hemodynamic relevance of coronary stenoses. In this method, an extremely thin wire carrying a pressure sensor at its tip is inserted into the coronary artery during coronary angiography and the blood pressure upstream and downstream of a coronary stenosis is compared after vascular dilatation has been achieved pharmacologically, usually with adenosine. If the quotient of poststenotic to prestenotic blood pressure is ≤0.8, hemodynamic relevance is present and patients benefit from revascularization.Based on the convincing evidence from studies, FFR measurement is listed as a class IA recommendation by the European Society of Cardiology for assessing the need for treatment of coronary stenosis.For several years, there have been scientific efforts to obtain information regarding the hemodynamic relevance of possible stenoses from invasive coronary angiography, which solely depicts the anatomy of the vessel lumen. Using different methodological approaches, several studies showed that fractional flow reserve can be simulated or calculated based on invasive coronary angiography.The purpose of this project is to scientifically evaluate angiography-based fractional flow reserve (FFRangio) simulation in order to contribute to the clinical validation of the method, to identify factors influencing diagnostic validity, and to enable further development of the method. New methods such as the FFRangio presented here must lead to robust results in order to be widely used in clinical practice. Therefore, the influence of the following parameters on the outcome of FFRangio and the correlation of FFRangio to established invasive FFR will be systematically evaluated:1. influence of cardiac phase2. influence of the frame rate 3. influence of stenosis localization4. inter-operator variability5. comparison of FFRangio with simulation of FFR from coronary CT angiography datasets.6. comparison of FFRangio with other invasive parameters for estimating the severity of coronary stenosis such as pd/pa, iFR, RFR.