Table 2 Morphologic spectrum of vulnerable coronary plaques.

Type of evolving plaque complication	Morphology of the underlying vulnerable plaque
Lumen thrombus caused by plaque rupture	Advanced plaques with thin fibrous cap, large lipid atheroma (>40% of plaque volume) and distinct inflammatory activity (T cells, macrophages and mast cells) in fibrous cap and shoulders
Lumen thrombus caused by endothelial erosion	Variable plaque architecture, many cases have a thick fibrous cap or completely fibrous skeleton; generally limited inflammatory activity, but often with subendothelial rim of foam cells and T cells
Expansion of plaque volume caused by intra‐plaque haemorrhage	Advanced plaques with complex fibro–lipid–calcific architecture and deeply seated collections of dilated thin walled micro vessels prone to leakage or disruption
Lumen thrombus caused by protruding calcific nodule	Advanced plaques with complex fibro–lipid–calcific architecture and calcified shell with sharp edges protruding into the lumen of the artery