Ge Xinyang, Liu Youjun, Tu Shengxian, Simakov Sergey, Vassilevski Yuri, Liang Fuyou
School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration (CISSE), Shanghai Jiao Tong University, Shanghai, 200240, China.
Int J Numer Method Biomed Eng. 2021 Nov;37(11):e3257. doi: 10.1002/cnm.3257. Epub 2019 Oct 10.
Although fractional flow reserve (FFR) and coronary flow reserve (CFR) are both frequently used to assess the functional severity of coronary artery stenosis, discordant results of diagnosis between FFR and CFR in some patient cohorts have been reported. In the present study, a computational model was employed to quantify the impacts of various pathophysiological factors on FFR and CFR. In addition, a hyperemic myocardial ischemic index (HMIx) was proposed as a reference for comparing the diagnostic performances of FFR and CFR. Obtained results showed that CFR was more susceptible than FFR to the influence of many pathophysiological factors unrelated to coronary artery stenosis. In particular, the numerical study proved that increasing hyperemic coronary microvascular resistance significantly elevated FFR while reducing CFR despite fixed severity of coronary artery stenosis, whereas introducing aortic valve disease only caused a significant decrease in CFR with little influence on FFR. These results provided theoretical evidence for explaining some clinical observations, such as the increased risk of discordant diagnostic results between FFR and CFR in patients with increased hyperemic microvascular resistance, and significant increase in CFR after surgical relief of severe aortic valve disease. When evaluated with respect to the predictive value for hyperemic myocardial ischemia, the performance of FFR was found to be considerably compromised in the presence of severe coronary vasodilation dysfunction or aortic valve disease, whereas the relationship between CFR and HMIx remained relatively stable, suggesting that CFR may be a more reliable indicator of myocardial ischemia under complex pathophysiological conditions.
尽管血流储备分数（FFR）和冠状动脉血流储备（CFR）都经常用于评估冠状动脉狭窄的功能严重程度，但已有报道称在一些患者队列中FFR和CFR之间存在诊断结果不一致的情况。在本研究中，采用了一种计算模型来量化各种病理生理因素对FFR和CFR的影响。此外，还提出了充血性心肌缺血指数（HMIx）作为比较FFR和CFR诊断性能的参考指标。所得结果表明，CFR比FFR更容易受到许多与冠状动脉狭窄无关的病理生理因素的影响。特别是，数值研究证明，尽管冠状动脉狭窄严重程度固定，但增加充血性冠状动脉微血管阻力会显著提高FFR，同时降低CFR，而引入主动脉瓣疾病只会导致CFR显著降低，对FFR影响很小。这些结果为解释一些临床观察结果提供了理论依据，例如充血性微血管阻力增加的患者中FFR和CFR诊断结果不一致的风险增加，以及严重主动脉瓣疾病手术缓解后CFR显著增加。当评估对充血性心肌缺血的预测价值时，发现FFR在存在严重冠状动脉血管舒张功能障碍或主动脉瓣疾病时性能会受到相当大的损害，而CFR与HMIx之间的关系保持相对稳定，这表明在复杂的病理生理条件下CFR可能是心肌缺血更可靠的指标。
