Atherosclerosis

On this page

Atherosclerosis: Definition & Risks - Hardening Arteries 101

Atherosclerosis: Chronic inflammation forming intimal fibro-fatty plaques (atheromas), causing arterial wall thickening, hardening, and stenosis.

  • Key Non-Modifiable Risk Factors:
    • Increasing Age
    • Male Gender
    • Family History
    • Genetic Predisposition
  • Key Modifiable Risk Factors:
    • Hyperlipidemia (↑LDL, ↓HDL, ↑Triglycerides)
    • Hypertension (e.g., BP > 130/80 mmHg)
    • Cigarette Smoking
    • Diabetes Mellitus
    • Obesity (BMI ≥ 30 kg/m²)
    • Physical Inactivity
    • Chronic Inflammation (e.g., ↑hs-CRP)

Atherosclerosis Risk Factors and Cardiovascular Disease

⭐ Hyperlipidemia (especially ↑LDL cholesterol) and cigarette smoking are the two most significant and modifiable risk factors accelerating atherogenesis.

Atherosclerosis: Pathogenesis - Plaque's Evil Plan

  • Trigger: Endothelial injury (↑ permeability, leukocyte adhesion).
  • Key Events:
    • LDL insudation & oxidation (oxLDL).
    • Monocytes → Macrophages → Foam cells (engulf oxLDL).
    • Smooth Muscle Cell (SMC) migration, proliferation, ECM deposition → Fibrous cap.
    • Necrotic core (lipids, debris) development.
  • Outcome: Complex plaque → Calcification, rupture, thrombosis.

⭐ Oxidized LDL (oxLDL) is pivotal, driving inflammation and macrophage transformation into foam cells.

Atherosclerosis plaque formation steps

Atherosclerosis: Morphology - Anatomy of Atheroma

  • Atheromatous Plaque (Atheroma): Focal intimal thickening; hallmark of atherosclerosis.
    • Key Structural Components:
      • Fibrous Cap: Superficial layer.
        • Composition: Smooth muscle cells (SMCs), dense collagen, elastin, proteoglycans.
        • Cells: Macrophages, T-lymphocytes.
      • Necrotic Core (Lipid Core): Central part, deep to cap.
        • Composition: Cholesterol crystals/esters, necrotic debris, foam cells (lipid-laden macrophages), fibrin, calcium.
      • Shoulder Region: Junction of cap and normal arterial wall; most cellular area.
        • Composition: Macrophages, T-cells, SMCs.
    • Neovascularization: Proliferation of small blood vessels at plaque periphery. Histological cross-sections of atherosclerotic plaques

⭐ The shoulder region, rich in inflammatory cells (macrophages, T-cells), is the most common site for plaque rupture, leading to thrombosis and acute coronary syndromes.

Atherosclerosis: Clinical Sequelae - Arterial Blockage Woes

  • Coronary Artery Disease (CAD): Angina, Myocardial Infarction (MI).
  • Cerebrovascular Disease (CVD): Transient Ischemic Attack (TIA), Stroke.
  • Peripheral Arterial Disease (PAD): Intermittent claudication, gangrene.
  • Aneurysms: Aortic (abdominal most common), iliac.
  • Renal Artery Stenosis: Secondary hypertension, renal failure.

Atherosclerosis: Affected Arteries & Conditions

⭐ Most common site for atherosclerosis is the abdominal aorta, followed by coronary arteries, popliteal arteries, internal carotid arteries, and circle of Willis.

  • Mesenteric Ischemia: Bowel infarction.
  • Sudden cardiac death often due to plaque rupture/thrombosis in CAD.

Atherosclerosis: Prevention Basics - Plaque Defense Tips

  • Lifestyle Modification:
    • Diet: ↓Saturated/trans fats, ↑fruits, vegetables, fiber.
    • Exercise: Aerobic, ≥150 min/week.
    • Smoking cessation.
    • Weight management: BMI <25 kg/m².
  • Pharmacological:
    • Statins (LDL-C goal <70-100 mg/dL based on risk).
    • Antiplatelet agents (e.g., Aspirin).
    • Blood pressure control (target <130/80 mmHg).

⭐ Statins are first-line for primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD).

High‑Yield Points - ⚡ Biggest Takeaways

  • Most common sites: Abdominal aorta > coronary > popliteal > carotid arteries.
  • Initiating event: Chronic endothelial injury/dysfunction.
  • Hallmark lesion: Atheromatous plaque (fibrous cap, necrotic lipid core).
  • Major modifiable risks: Smoking, hypertension, diabetes, hyperlipidemia (↑LDL, ↓HDL).
  • Earliest lesion: Fatty streaks (lipid-laden macrophages/foam cells).
  • Key complications: Myocardial infarction, stroke, aortic aneurysms, peripheral vascular disease.

Practice Questions: Atherosclerosis

Test your understanding with these related questions

Plaques jaunes are seen in which condition?

1 of 5

Flashcards: Atherosclerosis

1/10

The intimal plaque that causes atherosclerosis consists of a necrotic lipid core (mostly _____) with a fibromuscular cap

TAP TO REVEAL ANSWER

The intimal plaque that causes atherosclerosis consists of a necrotic lipid core (mostly _____) with a fibromuscular cap

cholesterol

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial