Superficial wall stress assessed from 4-D analysis of coronary angiography in vivo

Acute coronary events are frequently caused by plaque rupture or plaque erosion. The mechanisms involved imply mechanical forces that act upon superficial plaque layers. Analyses of the stress to the superficial coronary vessel wall may help understand the mechanisms involved and might ultimately allow assessing pharmacological approaches aimed at increasing the biomechanical stability of plaques. We recently developed a novel approach of 4-dimensional (4D) analysis of superficial wall stress (SWS) on coronary arteries by combining imaging processing with a semi-inverse finite element method (Fig. 1). Angiographic reconstruction was performed to reconstruct the interrogated vessel at several phases of the cardiac cycle. Then, the motion trajectory of each node during heartbeat is implemented by its respective displacement loads, determined by optimal node-to-node mapping between adjacent finite element configurations. This approach does not need to delineate plaque components and structures or to implement data on dynamic blood pressure, as the complex interaction thereof is intrinsically incorporated in the cyclic changes in lumen geometries, which are used as inputs to compute SWS by the proposed approach. Pending validation, this novel approach may be used as a tool to evaluate superficial coronary wall stress and its potential impact on future coronary events.