Assessing Left Main Bifurcation Anatomy and Haemodynamics: A Potential
Surrogate for Disease Risk in Suspected Coronary Artery Disease Without
Stenosis?
Coronary anatomy governs local haemodynamics associated with atherosclerotic
development, progression and ultimately adverse clinical outcomes. However,
lack of large sample size studies and methods to link adverse haemodynamics to
anatomical information has hindered meaningful insights to date.
The Left Main coronary bifurcations of 127 patients with suspected coronary
artery disease in the absence of significant stenosis were segmented from CTCA
images before computing the local haemodynamics. We correlated 11 coronary
anatomical characteristics with the normalised lumen area exposed to adverse
haemodynamics linked with atherosclerotic processes. These include mean
curvatures and diameters of branches, bifurcation and inflow angles, and
Finet's ratio as the anatomical parameters, and low Time-Averaged Endothelial
Shear Stress (lowTAESS0.1), and
high Relative Residence Time (highRRT>4.17 1/Pa) for the haemodynamic
consideration. We separately tested if the geometric measures and haemodynamics
indicators differed between subgroups (sex, smokers, and those with
hypertension). We then use a step-down multiple linear regression model to find
the best model for predicting lowTAESS, highOSI and highRRT.
Finet's Ratio (FR) significantly correlated to lowTAESS (p<0.001). Vessel
diameters and curvature correlated to highOSI (both p<0.001). Finet's ratio,
vessel diameters and daughter branch curvature independently correlated to RRT
(all p<0.01).
Our results indicate that specific anatomical vessel characteristics may be
used as a surrogate of adverse haemodynamic environment associated with
clinically adverse mechanisms of disease. This is especially powerful with the
latest computing resources and may unlock clinical integration via standard
imaging modalities as biomarkers without further computationally expensive
simulations.Comment: 14 pages, 2 figure