冠脉狭窄与心肌缺血定量关系的生物力学研究

冠脉狭窄程度与其造成功能性心肌缺血间无绝对相关性，冠脉血流储备分数(FFR)是目前评价功能性心肌缺血的金标准，最近又发展了瞬时无波型比(iFR)评价指标；iFR和FFR都是有创检查，临床应用受到局限；建立无创的心肌缺血评价方法来指导冠脉狭窄临界病变的治疗是一个亟待解决的难题。本项目拟结合iFR和FFR的优势，将混合iFR/FFR作为心肌缺血的评价指标，采用生物力学仿真建模的方法，数值计算iFR/FFR，无创获得冠脉狭窄与心肌缺血的定量关系：基于患者冠脉CTA图像，结合个性化冠脉集中参数模型，构建0D-3D耦合的闭环几何多尺度血流动力学模型；采用CFD方法数值计算静息和最大充血状态下冠脉内的流场和压力，无创获得患者冠脉狭窄的iFR/FFR；以有创iFR/FFR为标准，明确无创iFR/FFR的诊断准确性，提高无创iFR/FFR的心肌缺血评价能力，开发快速准确的无创iFR/FFR数值计算系统。

Myocardial ischemia has no absolute relationships with coronary artery stenosis, and the assessing method currently used for myocardial ischemia, Fractional Flow Reserve(FFR) , along with newly developed promising instantaneous Wave-Free Ratio(iFR), are both invasive, which constricts their wide applications in clinics. It is of great urgent demands to develop a noninvasive method for evaluating myocardial ischemia in coronary intervention decision making. In this project, the hybrid iFR/FFR, which combines the advantages of both FFR and iFR, will be chosen as the assessment index for myocardial ischemia, and the biomechanical modeling and simulation method will be used to identify the patient-specific quantitative relationships between coronary stenosis and myocardial ischemia. Firstly, based on the combination of CTA images and.individualized lumped parameter model of coronary microcirculation, the 0D-3D close-looped geometrical multiscale hemodynamic model of coronary circulation will be built, and the CFD method will be utilized to numerically determine the flow and pressure field in coronary at rest and hyperemic state, from which the iFR/FFR can be obtained noninvasively. Secondly, clinical experiments will be conducted to certify the numerical method, and to improve the simulation model achieving the best calculating precision of iFR/FFR. Finally, the application system of.noninvasive iFR/FFR calculation will be developed to fulfill the clinical need for convenient, quick and accurate assessment of myocardial ischemia.