Atherosclerosis

What is the difference between:

•Arteriosclerosis•Atherosclerosis•Atheroma

Answer:

• Arteriosclerosis: A group of diseases related by hardening arteries, of which atherosclerosis is one.• Atherosclerosis: A disease involving hardening, narrowing

and weakening of the arterial wall, characterised by the presence of atheromas. • Atheroma: A chronic lesion in the intima tunica of the artery,

characterised by the pathological build-up of lipids, inflammatory cells and smooth muscle.

Histopathological Changes

1) Injury to the endothelium allows LDL into the intima, this LDL starts to oxidize.

2) Macrophage invade the intima and ingest the oxidized LDL, becoming pathological foam cells because they can not break it down.

3) Foam cells recruit other white blood cells and activate a generalised immune response, causing inflammation.

4) Foam cells release growth factors which cause smooth muscle infiltration from the media into the intima, further narrowing the artery.

5) Smooth muscle can begin to calcify and become brittle, leading to rupture and embologenesis.

What are the macroscopic stages?

1) Fatty Streaks

• Irregular patches• Matter is beneath intima

(fibrous cap)• Mostly foam cells at this

point• Smooth muscle cell

infiltration has also begun

2) Fibrofatty Plaque

• Atheroma now much more widespread• Lots of smooth muscle

infiltration• Filled with lots of other stuff like

fibrin, collagen and bits of cells.• Calcification may have begun.

3) Complicated/Advanced Plaque

Presence of one or more of:• Cracking of fibrous cap• Bleeding into the atheroma• Superimposed thrombus• Very large fibrous cap

Complications of Atherosclerosis - CHEAT

•Critical Stenosis – e.g. Peripheral Vascular Disease

•Haemorrhage – i.e. Burst Vessel

•Embolism•Aneurysm – Can then develop into lots of problems

•Thrombosis in situ

Diagnosis

• Usually secondary to whatever the complication is.• Angiography is the gold standard.• High cholesterol does not necessarily mean atherosclerosis, but there

is a strong link.• Look for signs and history to screen for hyperlipidaemia.• Patient history of hypertension, family history of familial

hypercholesterolaemia, social history of poor diet and smoking. • Xanthelasma – well-defined lumps of fat around eyes.

Treatments

• Stop health-damaging behaviours – smoking, fatty diet, low exercise • Treat hypertension and

hyperlipidaemia • Stenting (Percutaneous)•Coronary Artery Bypass Graft (CABG)