Angina Pectoris

Types of Angina

 Angina pectoris is a clinical syndrome characterized by myocardial ischemia due to an imbalance between oxygen supply and demand, without acute myocardial necrosis. Understanding the different types of angina is essential for appropriate pharmacotherapy selection, patient counseling, and risk stratification.

1. Stable Angina (Chronic Stable Angina)

Definition

Predictable chest discomfort precipitated by physical exertion or emotional stress and relieved by rest or nitroglycerin. Pathophysiology

  • Fixed atherosclerotic narrowing of ≥70% in one or more coronary arteries
  • Myocardial oxygen demand exceeds supply during stress

Clinical Features

  • Substernal pressure or tightness
  • Radiates to left arm, neck, jaw, or back
  • Duration usually <10 minutes
  • Reproducible pattern

Pharmacist Clinical Focus

  • First-line therapy:
    • Beta-blockers (reduce heart rate and myocardial oxygen demand)
    • Nitrates (symptomatic relief)
  • Secondary prevention:
    • Antiplatelets (ASA)
    • Statins
    • ACE inhibitors (selected patients)
  • Assess adherence, nitrate tolerance, and beta-blocker contraindications

2. Unstable Angina (Acute Coronary Syndrome – Non-ST Elevation)

Definition

Angina that is new-onset, worsening, or occurs at rest, indicating an increased risk of myocardial infarction. Pathophysiology

  • Plaque rupture or erosion
  • Partial thrombotic occlusion
  • Reduced coronary blood flow at rest

Clinical Features

  • Increasing frequency, severity, or duration
  • Occurs with minimal exertion or at rest
  • Poor response to usual antianginal therapy

Pharmacist Clinical Focus

  • Medical emergency
  • Initiate or verify use of:
    • Dual antiplatelet therapy
    • Anticoagulation
    • High-intensity statins
    • IV nitrates and beta-blockers (if appropriate)
  • Monitor bleeding risk, renal function, and drug–drug interactions

3. Prinzmetal (Variant) Angina

Definition

Episodic chest pain caused by coronary artery vasospasm, typically occurring at rest. Pathophysiology

  • Transient coronary vasoconstriction
  • May occur in normal or mildly diseased arteries

Clinical Features

  • Occurs at rest, often nocturnally or early morning
  • Transient ST-segment elevation during episodes
  • Not related to exertion

Pharmacist Clinical Focus

4. Microvascular Angina (Cardiac Syndrome X)

Definition

Angina-like chest pain with normal epicardial coronary arteries, due to microvascular dysfunction. Pathophysiology

  • Impaired coronary microcirculation
  • Endothelial dysfunction
  • Common in women

Clinical Features

  • Chest pain with exertion or stress
  • Normal coronary angiography
  • Symptoms may be prolonged and severe

Pharmacist Clinical Focus

  • Symptom control may require:
  • Limited response to nitrates
  • Address comorbidities (hypertension, diabetes, dyslipidemia)

5. Refractory Angina

Definition

Chronic angina that persists despite optimal medical therapy and revascularization. Pathophysiology

  • Advanced coronary artery disease
  • Limited revascularization options

Clinical Features

  • Frequent anginal episodes
  • Reduced quality of life

Pharmacist Clinical Focus

  • Optimize combination therapy
  • Consider newer agents (e.g., ranolazine, ivabradine where applicable)
  • Monitor QT interval, renal and hepatic function
  • Emphasize adherence and lifestyle modification

Summary Table (Quick Reference)

Type Trigger Symptoms Key Mechanism First-Line Therapy
Stable Exertion
– Atherosclerosis causing fixed coronary artery narrowing
– Triggers: physical activity, emotional stress, cold/hot exposure, heavy meals 		 – Predictable chest pain with exertion or stress
– Pain lasts ≤5 minutes, relieved by rest or nitrates
– Pain may radiate to jaw, neck, arms, back		 Fixed coronary stenosis Beta-blocker, nitrates
– Rest and short-acting nitrates (e.g., sublingual nitroglycerin) for immediate relief
– Beta blockers or calcium channel blockers preferred for chronic management
Unstable Rest or minimal exertion
– Ruptured atherosclerotic plaque, thrombosis leading to sudden blood flow reduction
– May worsen over time

– Unexpected severe chest pain at rest or minimal exertion
– Pain lasts >20 minutes, not relieved by rest or nitrates
– Possible progression to myocardial infarction

 Plaque rupture, thrombosis Antiplatelets, anticoagulants
– Aspirin and statins for secondary prevention
– Medical emergency requiring immediate evaluation and treatment
– Antiplatelet agents, anticoagulants, possible revascularization procedures (PCI or CABG)
Variant (Prinzmetal) Angina – Occurs often in younger patients, often near fixed coronary artery lesions
– Coronary artery spasm possibly triggered by stress, smoking, cocaine, cold weather		 – Severe chest pain often at rest, mainly night/early morning
– Pain relieved by vasodilators		 Coronary vasospasm CCBs, nitrates
 Calcium channel blockers and long-acting nitrates
– Avoid triggers such as smoking, cocaine
Microvascular Exertion/stress
– Dysfunction of small coronary vessels (coronary microvascular disease)
– More common in women, especially peri- or postmenopausal		 – Severe, prolonged chest pain, sometimes >30 minutes
– Pain may happen at rest or activity, associated with fatigue, shortness of breath		 Microvascular dysfunction Beta-blockers, ACEIs
– May not respond well to nitrates
– Management includes medications that improve microvascular function and lifestyle changes
– Beta blockers, calcium channel blockers, ACE inhibitors can be used
Refractory Any   Severe CAD Combination therapy
Tags: , ,