Wu Xinlei, von Birgelen Clemens, Zhang Su, Ding Daixin, Huang Jiayue, Tu Shengxian
Biomedical Instrument Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
Shanghai Med-X Engineering Research Center, Shanghai Jiao Tong University, Shanghai, China.
Int J Cardiovasc Imaging. 2019 Sep;35(9):1563-1572. doi: 10.1007/s10554-019-01611-y. Epub 2019 May 3.
The measurement of fractional flow reserve (FFR) and superficial wall stress (SWS) identifies inducible myocardial ischemia and plaque vulnerability, respectively. A simultaneous evaluation of both FFR and SWS is still lacking, while it may have a major impact on therapy. A new computational model of one-way fluid-structure interaction (FSI) was implemented and used to perform a total of 54 analyses in virtual coronary lesion models, based on plaque compositions, arterial remodeling patterns, and stenosis morphologies under physiological conditions. Due to a greater lumen dilation and more induced strain, FFR in the lipid-rich lesions (0.81 ± 0.15) was higher than that in fibrous lesions (0.79 ± 0.16, P = 0.001) and calcified lesions (0.79 ± 0.16, P = 0.001). Four types of lesions were further defined, based on the combination of cutoff values for FFR (0.80) and maximum relative SWS (30 kPa): The level of risk increased from (1) plaques with mild-to-moderate stenosis but negative remodeling for lipid-rich (Type A: non-ischemic, stable) to (2) lipid-rich plaques with mild-to-moderate stenosis and without-to-positive remodeling (Type B: non-ischemic, unstable) or plaques with severe stenosis but negative remodeling for lipid-rich (Type C: ischemic, stable) to (3) lipid-rich plaques with severe stenosis and without-to-positive remodeling (Type D: ischemic, unstable). The analysis of FSI to simultaneously evaluate inducible myocardial ischemia and plaque stability may be useful to identify coronary lesions at a high risk and to ultimately optimize treatment. Further research is warranted to assess whether a more aggressive treatment may improve the prognosis of patients with non-ischemic, intermediate, and unstable lesions.
血流储备分数（FFR）和表面壁应力（SWS）的测量分别可识别诱发性心肌缺血和斑块易损性。目前仍缺乏对FFR和SWS的同时评估，而这可能对治疗产生重大影响。基于生理条件下的斑块成分、动脉重塑模式和狭窄形态，实施了一种新的单向流固耦合（FSI）计算模型，并用于在虚拟冠状动脉病变模型中总共进行54次分析。由于管腔扩张更大且诱导应变更多，富含脂质的病变中的FFR（0.81±0.15）高于纤维性病变（0.79±0.16，P = 0.001）和钙化性病变（0.79±0.16，P = 0.001）。基于FFR的临界值（0.80）和最大相对SWS（30 kPa）的组合，进一步定义了四种类型的病变：风险水平从（1）轻度至中度狭窄但富含脂质的负向重塑斑块（A型：非缺血性、稳定）增加到（2）轻度至中度狭窄且无重塑至正向重塑的富含脂质斑块（B型：非缺血性、不稳定）或严重狭窄但富含脂质的负向重塑斑块（C型：缺血性、稳定），再到（3）严重狭窄且无重塑至正向重塑的富含脂质斑块（D型：缺血性、不稳定）。同时评估诱发性心肌缺血和斑块稳定性的FSI分析可能有助于识别高危冠状动脉病变并最终优化治疗。有必要进行进一步研究，以评估更积极的治疗是否可以改善非缺血性、中度和不稳定病变患者的预后。
