Relationship Between the Dynamic Geometry and Wall Thickness of a Human Coronary Artery

Abstract

Objective-It is widely recognized that hemodynamic and wall mechanical forces are involved in the initiation and development of atherosclerosis. In the coronary vasculature, these forces are likely mediated by arterial dynamics and geometry. This research examines the hypothesis that coronary artery motion and geometry affect the local predisposition to disease, presumably through their influence on the stresses at and in the artery wall. Methods and Results-The dynamics of a human right coronary artery and the variation of wall thickness along its length were characterized from biplane cineangiograms and intravascular ultrasound records, respectively. The dynamic geometry parameters were distance along the vessel, cyclic displacement, axial strain, curvature, and torsion. Multiple regression analyses using principal components show that (1) no single dynamic geometry parameter has a dominant influence on wall thickness, (2) Key Words: coronary arteries Ⅲ dynamic geometry Ⅲ wall thickness Ⅲ biplane angiography Ⅲ intravascular ultrasound A lthough several cardiovascular risk factors, including hypercholesterolemia, hypertension, smoking, and diabetes, have been associated with coronary heart disease (CHD), 1,2 it is conventional knowledge among investigators in atherosclerosis that these factors can explain no more than half of the variability in the occurrence of atherosclerotic lesions or CHD. [3][4][5] This situation suggests that there are additional risk factors that predispose to arterial disease. Friedman and colleagues 6 -8 have proposed that variations in arterial geometry, including the dynamic characteristics of the coronary arteries, can contribute to some of the unexplained variation in cardiovascular risk. This idea is based on the abundant and increasing evidence that hemodynamics and vascular wall stresses play an important role in the initiation and development of atherosclerosis. 9,10 The fluid dynamic environment at the arterial wall depends on the geometry and motion of the channel through which the flow is passing, and geometries that promote an adverse hemodynamic milieu could constitute additional risk factors for disease. Similarly, the motion of the coronary arteries during the cardiac cycle can lead to cyclic stresses in the wall that may prompt an atherosclerotic response.Most research seeking associations between coronary artery geometry and vessel pathology has been based on autopsy hearts. [11][12][13][14] This is in part because of a lack of relevant data for the in vivo situation. Biplane cineangiography and intravascular ultrasound (IVUS) are 2 powerful modalities for assessing this relationship in vivo. While the former modality makes it possible to accurately reconstruct the time-dependent 3D course of the coronary vessels on the beating heart, the latter provides the necessary in vivo vessel wall morphology. In this study, we demonstrate the use of these diagnostic techniques to evaluate the relationship between the dynamic geometry and morphometry of a human right coronary ar...

Relation between plaque type, plaque thickness, blood shear stress, and plaque stress in coronary arteries assessed by X‐ray Angiography and Intravascular Ultrasound

“…The measurements confirmed observations of previous clinical and technical studies, 1,18,19,22,26,46 thus illustrating the capabilities of the tool.…”

“…Globally, the membrane stress distribution (Von Mises stress), which depends on the plaque thickness and the plaque characteristics by definition, results inversely proportional to the blood shear stress. These findings are in agreement with the results shown in the previous studies, 1,18,19,22,26 and this qualitative evaluation has been corroborated in Sec. III.C by quantitative statistical evaluations.…”

“…Although several epidemiological risk factors have been associated with coronary heart disease (CHD), 1 several studies suggest that there are additional causes that predispose to arterial disease. In particular, there is an abundant and increasing evidence that the combination of morphological and biomechanical (hemodynamics and vascular stresses) factors play an important role in the initiation and development of atherosclerosis, thus potentially leading to cardiovascular accidents such as plaque rupture.…”

Anatomical Risk Factors Of Coronary Heart Disease

“…Considering the fact that it has a big role in blood supply of the heart and serious diseases as atherosclerosis, left coronary artery and its branches have been an important issue for studies. [1][2][3][4][5][6] Although several cardiovascular risk factors, such as hypercholesterolemia, diabetes, hypertension and smoking have been associated with coronary heart disease (CHD), it is a conventional knowledge that these factors can explain only the half of the variability in the occurrence of atherosclerosis or CHD. [3,[6][7][8][9] This means that there are additional risk factors that predispose atherosclerosis and CHD.…”

Myocardial bridges are free from atherosclerosis: Overview of the underlying mechanisms

“…As long as the epicardial coronary segments are closely attached to the beating heart, they sustain a periodic motion during the cardiac cycle. Pulsatile coronary motion affects coronary geometry and this, in turn, influences the local hemodynamic environment, initiating a self-perpetuating vicious cycle, which drives atherosclerosis (16,27). Lyon et al (28) studied the effect of arterial wall motion on the development of atherosclerosis in cynomolgus monkeys fed an atherosclerotic diet, and concluded that the inhibition of wall motion may confer protection against atherosclerosis.…”