Coronary Artery Disease

Overview of Coronary Artery Disease (CAD)

• CAD primarily results from coronary artery atherosclerosis, causing myocardial ischemia.
• Acute coronary syndromes (ACS) arise from unstable plaques, which can rupture and form thrombus.

Risk Factors for CAD

• Non-modifiable:

  • Age: Increased risk with older age.
  • Gender: Males at higher risk until age 50.
  • Genetics: Family history of coronary artery disease.

• Modifiable:

  • Hypertension: Major contributor to CAD.
  • Dyslipidaemia: Abnormal lipid levels increase risk.
  • Diabetes: Significant risk factor for CAD development.
  • Obesity: Associated with various cardiovascular risks.
  • Smoking: Directly impacts cardiovascular health.
  • Mental stress: Can trigger or exacerbate heart conditions.
  • Sedentary lifestyle: Inactivity leads to increased risk.

Pathophysiology of Atherosclerosis

• Plaque formation in arteries involves shear stress and lipid deposition.
• Plaque structure:
  • Stable plaques: Thick caps, small lipid cores, lead to stable angina due to chronic narrowing.
  • Unstable plaques: Thin caps, prone to rupture, associated with ACS.

Types of Angina

• Stable Angina: Characterized by predictable chest pain with exertion that resolves with rest or nitrates; typically brief.
• Unstable Angina:
  • Crescendo angina: Increased frequency, duration, and severity.
  • Angina at rest, post-ACS, and de novo angina.

Myocardial Infarction (MI)

• Type 1 MI: Plaque rupture leading to thrombus formation and arterial occlusion.
• Type 2 MI: Results from an imbalance in myocardial oxygen demand vs. supply, influenced by various conditions (e.g., coronary spasm, hypotension).

Clinical Examination

• Physical exams may be unremarkable; vital signs assessments are crucial.
• High-risk features:
  • Low systolic blood pressure (<100 mm Hg).
  • Elevated jugular venous pressure.
  • Abnormal heart sounds.
  • Rales or crackles in lungs.

Management of Acute Coronary Syndromes (ACS)

• STEMI Treatment Objectives:

  • Rapid restoration of coronary blood flow within 12-24 hours.
  • Primary Percutaneous Coronary Intervention (PPCI) is preferred.

• Adjunctive Therapy:

  • Dual antiplatelet therapy (DAPT): Aspirin combined with a P₂Y₁₂ inhibitor for 12 months.
  • Anticoagulants: Unfractionated heparin or enoxaparin.

• Additional Drug Therapy:

  • Beta-blockers for patients, especially with reduced ejection fraction.
  • High-intensity statin therapy to lower LDL cholesterol.
  • ACE inhibitors or ARBs for high-risk patients (heart failure, diabetes).

Treatment of Chronic Coronary Syndromes

• Goals: Alleviate angina and reduce adverse cardiovascular events.

• Pharmacological Management:

  • Nitrates: For acute and long-term angina relief.
  • Beta-blockers: Decrease heart rate and myocardial oxygen demand.
  • Calcium Channel Blockers: Primarily for vasodilation.
  • Ivabradine: Selectively lowers heart rate without affecting blood pressure.

• Event Prevention:

  • Antiplatelet Agents: Aspirin and alternatives if allergic.
  • Statins: Recommended for all patients with established SCAD.
  • ACE inhibitors: For patients with hypertension or diabetes, unless contraindicated.

Angina Characteristics

• Typical Angina: Specific location (retrosternal), pressure-like pain, triggered by exertion, relieved by rest/nitrates.
• Atypical Angina: Meets two criteria of typical angina.
• Non-anginal Chest Pain: Lacks typical characteristics.

Classification of Angina Severity

• Class I: No angina with ordinary activity.
• Class II: Slight limitation during ordinary activities.

This quiz focuses on the pharmacological approaches for managing stable coronary artery disease, particularly the use of anti-ischaemic drugs like nitrates. Participants will learn the mechanisms by which these medications relieve angina pain and prevent further cardiovascular events. Understanding these interventions is crucial for effective patient care in cardiovascular health.