Calcified coronary artery disease: Mechanisms, risk factors and clinical consequences

Table 1 Comparison between non-eruptive nodular calcification and eruptive calcified nodules

Feature	Non-eruptive nodular calcification	Eruptive calcified nodule
Histological characteristics	Nodular calcium protrusion covered by an intact fibrous cap; usually reflects advanced fibrocalcific plaque remodeling	Disrupted fibrous cap overlying protruding nodular calcium, frequently associated with endothelial denudation and luminal thrombus
OCT characteristics	Protruding calcific mass with an irregular surface but preserved overlying fibrous tissue; absence of definite thrombus	Protruding calcific mass with surface disruption, signal-rich thrombus, and irregular luminal contour
IVUS characteristics	Superficial convex calcific protrusion with acoustic shadowing; preserved luminal continuity	Protruding superficial calcium with marked acoustic shadowing, irregular luminal surface, and possible thrombotic material
Usual clinical context	Often associated with stable or healed fibrocalcific plaques; may contribute to lesion rigidity and PCI complexity	Associated with acute coronary syndromes, coronary thrombosis, and higher risk of recurrent events
Procedural implications	May impair balloon expansion and stent apposition; often requires lesion modification	High-risk lesion requiring careful thrombus assessment, intracoronary imaging, and adequate calcium modification before stenting

IVUS: Intravascular ultrasound; OCT: Optical coherence tomography; PCI: Percutaneous coronary intervention.