Cataloguing the geometry of the human coronary arteries: A potential tool for predicting risk of coronary artery disease

BackgroundThe non-uniform distribution of atherosclerosis in the human vasculature suggests that local fluid dynamics or wall mechanics may be involved in atherogenesis. Thus certain aspects of vascular geometry, which mediates both fluid dynamics and wall mechanics, might be risk factors for coronary atherosclerosis. Cataloguing the geometry of normal human coronary arteries and its variability is a first step toward identifying specific geometric features that increase vascular susceptibility to the disease.MethodsImages of angiographically normal coronary arteries, including 32 left anterior descending (LAD) and 35 right coronary arteries (RCA), were acquired by clinical biplane cineangiography from 52 patients. The vessel axes in end diastole were reconstructed and geometric parameters that included measures of curvature, torsion and tortuosity were quantified for the proximal, middle and distal segments of the arteries.ResultsStatistical analysis shows that (1) in the LAD, curvature, torsion and tortuosity are generally highest in the distal portion, (2) in the RCA, these parameters are smallest in the middle segment, (3) the LAD exhibits significant higher torsion than the RCA (P < 0.005), and (4) > 80% of the variability of coronary arterial geometry can be expressed in terms of two factors, one dominated by the curvature measures and tortuosity, and the other emphasizing the torsion parameters.ConclusionsThis study has comprehensively documented the normal arterial geometry of the LAD and RCA in end diastole. This information may be used to guide the identification of geometric features that might be atherogenic risk factors.