Vulnerable plaque

A vulnerable plaque is a kind of atheromatous plaque – a collection of white blood cells (primarily macrophages) and lipids (including cholesterol) in the wall of an artery – that is particularly unstable and prone to produce sudden major events such as a heart attack or stroke.

The defining characteristics of a vulnerable plaque include but are not limited to: a thin fibrous cap, large lipid-rich necrotic core, increased plaque inflammation, vascular remodeling, increased vasa-vasorumneovascularization, and intra-plaque hemorrhage. These characteristics together with the usual hemodynamic pulsating expansion during systole and elastic recoil contraction during diastole contribute to a high mechanical stress zone on the fibrous cap of the atheromatous plaque, making it prone to plaque rupture. Plaque rupture releases highly thrombogenic core material into the vessel lumen and can cause acute thrombotic occlusion resulting in heart attack or stroke. A vulnerable plaque may also suddenly hemorrhage into the core causing expansion of the plaque and severe stenosis or occlusion. Repeated non-occlusive atheroma rupture and healing may result in worsening arterystenosis.