Atherosclerotic plaques

Atherosclerotic Plaques
Other names	Atheroma, Arteriosclerotic vascular disease
Specialty	Cardiology, Vascular surgery

Atherosclerotic plaques are accumulations of lipids, calcium, fibrous tissue, and other cellular debris within the walls of arteries. This buildup can lead to the narrowing and hardening of the arteries, a condition known as atherosclerosis, which is a major form of cardiovascular disease. Atherosclerotic plaques are significant because they can restrict blood flow, leading to ischemia of the tissues supplied by the affected arteries and potentially resulting in severe health events such as heart attacks, strokes, or peripheral artery disease.

Pathophysiology

The development of atherosclerotic plaques is a complex process that typically begins with damage to the endothelial layer of an artery. Factors contributing to endothelial damage include hypertension, smoking, diabetes mellitus, and high levels of low-density lipoprotein (LDL) cholesterol. Following endothelial injury, LDL cholesterol accumulates in the artery wall and undergoes oxidation, triggering an inflammatory response. Monocytes migrate to the site, transforming into macrophages that ingest the oxidized LDL, becoming foam cells. These foam cells accumulate to form the fatty streak, the earliest visible lesion of atherosclerosis.

As the lesion progresses, smooth muscle cells migrate from the media to the intima, proliferate, and produce extracellular matrix, forming a fibrous cap over the fatty streak. This cap, along with the underlying area of lipid accumulation and necrotic cellular debris, constitutes the mature atherosclerotic plaque. Plaques that are prone to rupture, leading to acute cardiovascular events, are characterized by a thin fibrous cap, large lipid core, and increased inflammatory cell activity.

Clinical Presentation

Symptoms of atherosclerosis vary depending on the arteries affected. Common manifestations include:

• Angina (chest pain) due to reduced blood flow to the heart muscle.
• Transient ischemic attacks or strokes from reduced cerebral blood flow.
• Claudication (leg pain with exercise) due to reduced blood flow to the limbs.

Diagnosis

Diagnosis of atherosclerotic plaques typically involves imaging techniques such as:

• Ultrasound (especially carotid ultrasonography)
• Computed tomography angiography (CTA)
• Magnetic resonance angiography (MRA)
• Coronary angiography, particularly for assessing coronary artery disease.

Treatment

Treatment focuses on reducing the risk of plaque progression and related complications. Strategies include:

• Lifestyle modifications such as diet, exercise, and smoking cessation.
• Medications to lower lipid levels (statins), manage hypertension, and control diabetes.
• Surgical interventions like angioplasty and vascular surgery in severe cases.

Prevention

Preventive measures are critical and include maintaining a healthy diet, regular physical activity, avoiding tobacco use, and managing risk factors such as hypertension, high cholesterol, and diabetes.

See Also

• Cardiovascular disease
• Coronary artery disease
• Lipid hypothesis
• Endothelial dysfunction