RESUMEN
Wall stress (WS) is associated with high arterial pressure and affects the localization of atherosclerotic lesions. We sought to non-invasively investigate the distribution of WS along the length of human coronary arteries and investigate its potential effect on atherosclerosis in association with vascular stiffness, local arterial curvature and plaque volume. We reconstructed three-dimensionally 28 coronary arteries from 22 subjects who had undergone coronary computed tomography angiography. Coronary arteries were divided in 2 mm-long segments. WS, vascular stiffness, plaque volume and curvature were calculated in each segment using computational fluid dynamics and morphology measurements. Plaque segments exhibited lower WS compared to their adjacent normal segments. Within plaques, WS was lower in the mid plaque portion compared to the upstream portion. Plaque volume was higher in the mid plaque portion compared to upstream and downstream portions. Low WS was associated with high curvature and both low WS and high curvature were associated with increased plaque volume. The current study demonstrates that WS and plaque volume are not uniform in the longitudinal axis of human coronary plaque. Calculation of WS could serve as a surrogate for the localization of plaque development and the identification of plaques at a more advanced stage of progression.
Asunto(s)
Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Tomografía Computarizada Multidetector , Placa Aterosclerótica , Anciano , Fenómenos Biomecánicos , Simulación por Computador , Enfermedad de la Arteria Coronaria/fisiopatología , Circulación Coronaria , Vasos Coronarios/fisiopatología , Estudios Transversales , Progresión de la Enfermedad , Femenino , Humanos , Imagenología Tridimensional , Modelos Lineales , Masculino , Persona de Mediana Edad , Modelos Cardiovasculares , Valor Predictivo de las Pruebas , Interpretación de Imagen Radiográfica Asistida por Computador , Estrés Mecánico , Rigidez VascularRESUMEN
INTRODUCTION: We sought to assess noninvasively the differences in hemorrheologic and geometric parameters between the left and right coronary artery (RCA). Low endothelial shear stress (ESS), high molecular viscosity (MV), and high wall stress (WS) induce atherosclerosis, while curvature and torsion have lately been implicated in the atherosclerotic process. METHODS: We studied 28 coronary arteries from 22 subjects undergoing coronary computed tomography angiography. We performed 3D reconstruction of the left anterior descending (LAD, n=14), left circumflex (LCx, n=5), and RCA (n=9) arteries. ESS, MV, and WS were calculated for 2-mm segments using computational fluid dynamics. Curvature and torsion were calculated for each segment using morphometric algorithms. RESULTS: A total length of 187 cm of coronary arteries was studied. ESS was higher in the LAD compared to the LCx and RCA (13.76 Pa vs. 3.49 Pa vs. 3.76 Pa, p<0.001); MV was higher in the LCx compared to the LAD and RCA (0.00542 Pa·s vs. 0.00173 Pa·s vs. 0.00240 Pa·s, p<0.001); and WS had higher values in the RCA compared to the LAD and LCx (289.98 mmHg vs. 255.93 mmHg vs. 235.18 mmHg, p<0.001). Curvature was greater in the LCx compared to the LAD and RCA (0.1447 mm-1 vs. 0.1229 mm-1 vs. 0.1234 mm-1, p<0.05), while torsion was found not to differ among the coronary arteries. CONCLUSIONS: Hemorrheologic and geometric parameters differ between the left and right coronary arteries. These factors, either alone or in association with local flow patterns and geometry, may affect the topography of atherosclerosis in the coronary arterial tree.
Asunto(s)
Aterosclerosis/fisiopatología , Vasos Coronarios/anatomía & histología , Vasos Coronarios/fisiología , Anciano , Algoritmos , Presión Arterial/fisiología , Aterosclerosis/diagnóstico por imagen , Viscosidad Sanguínea/fisiología , Angiografía Coronaria/métodos , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/fisiopatología , Electrocardiografía/métodos , Femenino , Hemorreología/fisiología , Humanos , Imagenología Tridimensional/métodos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resistencia al Corte , Estrés MecánicoRESUMEN
We sought to noninvasively assess the relationship between arterial remodeling, endothelial shear stress (ESS), and wall stiffness in coronary arteries. We studied 28 coronary arteries from 22 patients undergoing coronary computed tomography angiography (CCTA). The ESS was calculated in 2-mm long segments using computational fluid dynamics. Local remodeling, plaque dimensions, and local wall stiffness were assessed in each segment. The ESS was lower in the regions of excessive expansive remodeling versus compensatory expansive versus inadequate expansive versus constrictive remodeling. Areas of decreased wall stiffness more frequently exhibited excessive expansive remodeling. Plaque volume was higher in segments showing excessive expansive and inadequate remodeling than segments with constrictive remodeling. In conclusion, CCTA enables the noninvasive assessment of coronary hemodynamics and arterial/plaque morphology. Excessive expansive remodeling is associated with high-risk plaque features, such as low ESS, decreased plaque stiffness, and increased plaque volume. This methodology may be useful in the risk assessment of individual coronary lesions.