What is arteriosclerosis, how does it lead to atherosclerosis, and what are its potential complications, including heart failure?

Arteriosclerosis: Definition, Relationship to Atherosclerosis, and Heart Failure Pathways

Definition of Arteriosclerosis

Arteriosclerosis is a general term referring to the stiffening and loss of elasticity of arterial walls, encompassing several distinct vascular pathologies including atherosclerosis, arteriolosclerosis, and Mönckeberg's medial calcific sclerosis. 1, 2

Key characteristics of arteriosclerosis include:

• Thickening and hardening of arterial walls, leading to decreased vessel compliance 1
• Progressive condition that increases with age and is influenced by various risk factors 3
• Results in increased arterial stiffness, which is measurable through techniques such as pulse-wave velocity 3
• Associated with increased systolic blood pressure and pulse pressure 3

Relationship Between Arteriosclerosis and Atherosclerosis

Arteriosclerosis and atherosclerosis are related but distinct processes:

• Atherosclerosis is a specific type of arteriosclerosis characterized by intimal lesions called atheromata or fibrofatty plaques 3

• Atherosclerosis is an inflammatory disease process that begins with lipid accumulation in the arterial wall 3

• The progression from arteriosclerosis to atherosclerosis involves:

  • Initial arterial stiffening (arteriosclerosis) creates hemodynamic conditions favorable for atheroma development 3
  • Increased pulse pressure and abnormal flow patterns in stiffened arteries promote atherogenic stress on vessel walls 3
  • Stiffened arteries lose normal impedance mismatch, allowing excessive pulsatile energy to be transmitted to distal vessels 3

• Pathological sequence:

  • Fatty streaks form as lipid-filled macrophages accumulate in the intima 3
  • Macrophages and smooth muscle cells proliferate and migrate into the intima and media 3
  • Fibrous plaques develop, which can become advanced and complicated 3
  • Vulnerable plaques may rupture, leading to thrombosis and vessel occlusion 4

• While arteriosclerosis and atherosclerosis often coexist, they are distinct pathophysiological entities with only a moderate association 3

Arteriosclerosis and Heart Failure Pathways

Arteriosclerosis contributes to heart failure through multiple mechanisms involving increased left ventricular load, impaired coronary perfusion, and promotion of atherosclerotic disease. 3

Direct Hemodynamic Effects:

• Increased left ventricular systolic load due to arterial stiffening 3

  • Contributes to ventricular remodeling and reduced mechanical efficiency
  • Increases myocardial oxygen demand

• Widened pulse pressure and reduced diastolic blood pressure 3

  • Compromises coronary perfusion during diastole
  • Creates a mismatch between oxygen supply and demand

• Impaired baroreceptor sensitivity and blood pressure regulation 3

  • Results in increased blood pressure lability
  • Reduces the ability to buffer short-term alterations in flow

Cardiac Structural and Functional Changes:

• Ventricular hypertrophy develops in response to increased afterload 3

  • Predisposes to heart failure through cellular apoptosis
  • Alters myocardial energetics and efficiency

• Impaired left ventricular diastolic function 3

  • Increases cardiac filling pressures
  • Further limits coronary perfusion
  • Contributes to diastolic heart failure

• Increased atrial load 3

  • Promotes atrial hypertrophy and fibrosis
  • May lead to atrial fibrillation, further compromising cardiac function

Atherosclerotic Complications:

• Arterial stiffness promotes atherosclerosis development 3

  • Coronary atherosclerosis is a common cause of heart failure 5
  • Myocardial ischemia and infarction lead to loss of functional myocardium

• Atherothrombotic events 3

  • Plaque rupture can cause acute coronary syndromes
  • Myocardial infarction results in permanent loss of cardiomyocytes

Clinical Progression:

• Arterial stiffness is independently associated with increased risk of heart failure 3
• Arterial stiffness is elevated in patients with established heart failure, regardless of whether left ventricular function is preserved or impaired 3
• The combination of arteriosclerosis and atherosclerosis creates a particularly high-risk scenario for heart failure development 3

Clinical Implications

• Early detection of arterial stiffness may identify individuals at risk for heart failure 3
• Interventions targeting arterial stiffness may help prevent heart failure development 3
• Management of risk factors common to both arteriosclerosis and atherosclerosis (hypertension, diabetes, dyslipidemia) is essential for prevention 3
• Physical training has been shown to improve arterial distensibility 3