Endothelial dysfunction allows lipoproteins to remain within the arterial wall, where they contribute to inflammation. This inflammatory environment recruits and alters local vascular cells, creating conditions that promote smooth muscle cell movement into the intima. The resulting cellular response begins the structural remodeling associated with plaque formation and progression.
After migrating into the intima, smooth muscle cells produce collagen that contributes to a fibrous cap over the lipid-rich portion of a lesion. This cap is a key structural feature because its integrity influences whether the plaque remains contained or becomes vulnerable to disruption, linking microscopic composition with clinical risk.
A plaque may enlarge within the arterial wall and progressively reduce the space available for blood flow, producing chronic narrowing. In a different course, the fibrous cap can become unstable and rupture. Rupture permits thrombosis, or clot formation, which can abruptly obstruct the vessel and produce an acute vascular event.
Risk assessment considers both the extent of arterial narrowing and the structural stability of the lesion. A plaque that substantially reduces the vessel lumen indicates progressive obstruction, while an unstable cap signals potential rupture and thrombosis. Evaluating these features helps connect plaque pathology with the likelihood of heart attack or stroke.
Their structure and severity can be assessed through diagnostic imaging and pathological analysis. These approaches provide information about the lesion’s extent, composition, and relationship to the arterial wall. Such findings help characterize disease progression, support cardiovascular risk assessment, and clarify whether plaque features may contribute to obstruction or acute complications.
Structural assessment shows whether disease is associated mainly with progressive narrowing or with features that could permit cap rupture and thrombosis. That distinction is clinically relevant because both mechanisms can impair blood flow, but sudden thrombotic obstruction creates an acute hazard. Plaque characterization therefore supports strategies aimed at preventing heart attack and stroke.