Abstract 4712: Necrotic Core Touching the Lumen is Most Frequently Exposed to High Shear Stress in Advanced Disease
Background Atherosclerotic plaques develop at locations in the arteries were the wall shear stress (WSS) is low. Eventually, plaques encroach into the lumen causing WSS increase. Minimal information is available on the relationship between WSS and plaque composition in human coronary arteries in vivo.
Methods We combined a 3D reconstruction technique of coronary arteries based on angiography and intravascular ultrasound with virtual histology data, which served to locate the necrotic core (NC) and necrotic core touching the lumen (NCTL). The lumen of these 3D reconstructions served as input for computational fluid dynamics. At 16 locations over the circumference, presence of NC and NCTL in the vessel wall lying behind that region was indicated and per cross section the WSS at those locations was compared to the median WSS (WSSmed) per cross section. Low and high WSS were defined as <WSSmed and >WSS respectively.
Results 10 human coronary arteries were 3D reconstructed including the plaque components. Cross sections with average wall thickness<0.5 mm were analyzed leaving us with 475 cross sections. In early plaques (plaque burden<40%), the NC was most frequently located at low WSS contrasting the advanced plaques (plaque burden>40%), being located at high WSS (60%, p<0.05 Mann-Whitney U test). NCTL was most often exposed to high WSS in advanced disease only (61% p<0.05).
Conclusion With advancement of disease NC is less often located at low WSS regions, but exposed to high WSS, which is probably the result of lumen narrowing. NCTL is exposed to high WSS. These data confirm that high WSS potentially contributes to plaque destabilization and thus enhance risk for myocardial infarction.