Most major blood-flow-stopping events occur at large plaques, which, before their rupture, produced very little if any stenosis.From clinical trials, 20% is the average stenosis at plaques that subsequently rupture with resulting complete artery closure. Most severe clinical events do not occur at plaques that produce high-grade stenosis. From clinical trials, only 14% of heart attacks occur from artery closure at plaques producing a 75% or greater stenosis before the vessel closing.If the fibrous cap separating a soft atheroma from the bloodstream within the artery ruptures, tissue fragments are exposed and released. These tissue fragments are very clot-promoting, containing collagen and tissue factor; they activate platelets and activate the system of coagulation. The result is the formation of a thrombus (blood clot) overlying the atheroma, which obstructs blood flow acutely. With the obstruction of blood flow, downstream tissues are starved of oxygen and nutrients. If this is the myocardium (heart muscle) angina (cardiac chest pain) or myocardial infarction (heart attack) develops. Accelerated growth of plaques
The distribution of atherosclerotic plaques in a part of arterial endothelium is inhomogeneous. The multiple and focal development of atherosclerotic changes is similar to that in the development of amyloid plaques in the brain and that of age spots on the skin. Misrepair-accumulation aging theory suggests that misrepair mechanisms play an important role in the focal development of atherosclerosis. Development of a plaque is a result of repair of injured endothelium. Because of the infusion of lipids into sub-endothelium, the repair has to end up with altered remodeling of local endothelium.
Microvasculitis refers to a range of diseases or presentations associated with a disease, where there is inflammation of small blood vessels:

Kawasaki disease
Susac syndrome

Nerve microvasculitis
Non-systemic vasculitic neuropathy (NSVN)
Hepatitis C-related cryoglobulinemia neuropathy (CRYOVASC)
Hepatitis B-associated PAN
Diabetic lumbosacral radiculoplexus neuropathy (DLRPN)
Non-diabetic lumbosacral radiculoplexus neuropathy (LRPN)
Diabetic cervical-radiculoplexus neuropathy (DCRPN)
Diabetic Cranio-Cervico-Radiculoplexus Neuropathy
Diabetic Cervical Neuropathy


== References ==