Importance of residual stress and basal tone in healthy and pathological human coronary arteries

While the effects of basal vascular tone (BVT) on the macroscopic stress-free configuration and on the intraparietal physiological stress/strain (PS/S) distribution in a healthy artery have been widely explored, the combined effects of residual stress/strain (RS/S), BVT, and in situ axial extension ratio on the PS/S distribution of healthy and pathological human coronary arteries remain unclear. As a result, they are largely ignored in the biomechanical and clinical analyses intended to diagnose the distensibility and vasodilatation performances of coronary arteries. The present study was therefore designed (1) to investigate ex vivo the macroscopic stress-free configurations of normal and atherosclerotic human coronary arteries, (2) to elucidate the combined effect of BVT and in situ axial stretch ratio on the PS/S distribution in healthy human coronary arteries by using an original hyperelastic homeostatic bilayered artery model accounting for the RS/S, and (3) to discuss the influence of RS/S on the biomechanical stability of human vulnerable coronary atherosclerotic plaques.