Coronary CT angiography-based estimation of myocardial perfusion territories for coronary artery FFR and wall shear stress simulation

Abstract

This study aims to apply a CCTA-derived territory-based patient-specific estimation of boundary conditions for coronary artery fractional flow reserve (FFR) and wall shear stress (WSS) simulation. The non-invasive simulation can help diagnose the significance of coronary stenosis and the likelihood of myocardial ischemia. FFR is often regarded as the gold standard to evaluate the functional significance of stenosis in coronary arteries. In another aspect, proximal wall shear stress ($$\mathrm{{WSS}_{prox}}$$ WSS prox ) can also be an indicator of plaque vulnerability. During the simulation process, the mass flow rate of the blood in coronary arteries is one of the most important boundary conditions. This study utilized the myocardium territory to estimate and allocate the mass flow rate. 20 patients are included in this study. From the knowledge of anatomical information of coronary arteries and the myocardium, the territory-based FFR and the $$\mathrm{{WSS}_{prox}}$$ WSS prox can both be derived from fluid dynamics simulations. Applying the threshold of distinguishing between significant and non-significant stenosis, the territory-based method can reach the accuracy, sensitivity, and specificity of 0.88, 0.90, and 0.80, respectively. For significantly stenotic cases ($$\mathrm{FFR}_{m}$$ FFR m $$\le$$ ≤ 0.80), the vessels usually have higher wall shear stress in the proximal region of the lesion.

Clinical Implications of High-Sensitivity Troponin Elevation Levels in Non-ST-Segment Elevation Myocardial Infarction Patients: Beyond Diagnostics

“…It has been discussed that the elevation of the biomarker is related to the amount of myocardial tissue compromised, and in turn, with the coronary vessel that irrigates it. This is because it has been estimated that these arteries differentially supply blood to the myocardium, with almost half of it supplied by the anterior descending artery (LAD) [35]. Therefore, it could be possible to identify and categorize myocardial tissue into LAD and non-LAD territories.…”

Time-resolved simulation of blood flow through left anterior descending coronary artery: effect of varying extent of stenosis on hemodynamics

“…2 ) fitted from the clinical measured FFR data of patients were used to define the inlet boundary conditions for LAD models. FFR is the ratio of maximal blood flow distal to a stenotic lesion to maximal flow in the same artery if hypothetically normal [ 9 ]. Pressure flow waveforms in the LADs were obtained from the subjects with FFR reflecting the physiologically pulsatile, biphasic blood flow from the coronary arteries into the LAD.…”

“…Since the blood flow in the coronary artery is a turbulent flow, current study used shear stress turbulence model to account for turbulent velocity due to its accuracy in predicting the turbulent behavior of blood in coronary arteries [ 9 , 26 , 27 ]. Additionally, the residual convergence criteria were set as 10 −4 .…”

“…Consequently, it is warranted to observe the surge of research into the pathogenesis of coronary stenosis lesion in the literature [ 3 – 6 ], which could enable clinicians to make more informed decisions when performing medical interventions. Among these studies, hemodynamic numerical simulation by means of computational fluid dynamics (CFD) simulation is deemed as a well-established method to study the hemodynamic mechanism of cardiovascular diseases [ 7 – 9 ], on the ground that it could quantify and three-dimensionally display hemodynamic distribution in coronary stenosis, thus providing a better understanding of the physiological and pathological basis of the lesion.…”

Recent technologies in cardiac imaging

“…WSS simulation can help diagnose the significance of coronary stenosis and the probability of myocardial ischemia ( 105 ). As FFR is becoming a new gold standard for assessing the functional significance of stenosis in coronary arteries, proximal wall shear stress (WSSprox) can also help reveal plaque susceptibility ( 106 ). FFR calculates the pressure variation perpendicular to the cross-sectional area of vessels, whereas WSSprox illustrates the tangential force adjacent to the lumen walls.…”