ateroma

Atheroma, or an atherosclerotic plaque, is a focal lesion of the inner lining of large and medium arteries characterized by the buildup of lipid-rich material within the intima. It is a core feature of atherosclerosis and can affect arteries throughout the body, including the coronary, carotid, and peripheral vessels.

The plaque typically consists of a lipid core composed of cholesterol esters and free cholesterol, necrotic debris, and foam cells formed by lipid-laden macrophages. This core is covered by a fibrous cap made of smooth muscle cells and collagen, and the lesion often contains inflammatory cells and varying degrees of calcification. The stability of the plaque depends on the thickness and integrity of the fibrous cap; a thin or inflamed cap is more prone to rupture.

Development is driven by endothelial dysfunction and lipid infiltration, with contributions from chronic inflammation and shear stress. Major risk factors include age, hyperlipidemia (especially elevated LDL cholesterol), hypertension, diabetes, smoking, obesity, and a family history of cardiovascular disease. The process is typically progressive and long-lasting, often asymptomatic until it causes significant arterial narrowing or complications.

Clinical consequences arise from luminal narrowing and potential plaque rupture with superimposed thrombosis. This can lead to ischemia in the heart, brain, or limbs, and may trigger events such as myocardial infarction or stroke. Diagnosis relies on clinical risk assessment and imaging techniques like ultrasound, CT angiography, or MRI. Treatment emphasizes lifestyle modification, lipid lowering with statins, blood pressure and glucose control, antiplatelet therapy as indicated, and revascularization in suitable cases.