Chronic stable angina

Related Subjects: |Assessing Chest Pain |Acute Coronary Syndrome (ACS) General |Aortic Dissection |Pulmonary Embolism |Acute Pericarditis |Diffuse Oesophageal Spasm |Gastro oesophageal reflux |Oesophageal Perforation Rupture |Pericardial Effusion_Tamponade |Pneumothorax |Tension Pneumothorax |Shingles |Analgesia and Pain management

💡 In people with angina-like symptoms but no flow-limiting epicardial coronary disease, consider microvascular angina (historically called Cardiac Syndrome X). Not all angina is caused by large-vessel coronary stenosis.

📖 About

• Stable angina is chest discomfort due to myocardial ischaemia, most often caused by atherosclerotic coronary artery disease.
• Symptoms are classically predictable, brought on by exertion or emotional stress, and relieved by rest or glyceryl trinitrate (GTN).
• Angina may also occur because of microvascular dysfunction, coronary vasomotor disorders, or conditions that increase myocardial oxygen demand or reduce supply.

🧬 Causes

• Obstructive coronary artery disease due to atherosclerotic plaque.
• Microvascular angina with no obstructive epicardial stenosis.
• Aortic stenosis, hypertrophic cardiomyopathy, anaemia, or thyrotoxicosis, which can provoke supply-demand mismatch.

📊 Canadian Cardiovascular Society (CCS) Angina Class

• Class I: Angina only with strenuous, rapid, or prolonged exertion.
• Class II: Slight limitation of ordinary activity.
• Class III: Marked limitation of ordinary physical activity.
• Class IV: Symptoms at rest or with minimal activity.

⚠️ Cardiovascular Risk Factors

• Smoking
• Hypertension
• Dyslipidaemia
• Diabetes mellitus
• Obesity and physical inactivity
• Increasing age
• Family history of premature coronary disease

🔑 Risk-factor modification is central: smoking cessation, blood pressure control, lipid lowering, diabetes management, exercise, and weight optimisation all reduce future cardiovascular events.

🩺 Clinical Features

• Central chest tightness, pressure, heaviness, or constriction.
• Triggered by exertion, cold weather, emotional stress, or heavy meals.
• Relieved by rest or GTN within minutes.
• May radiate to the left arm, both arms, jaw, neck, back, or epigastrium.
• Some patients, especially older adults, women, and people with diabetes, may present with breathlessness or atypical discomfort rather than classic pain.

🖥️ CT coronary angiography (CTCA) is the recommended first-line test in NICE guidance for people with suspected recent-onset stable angina. It provides a non-invasive anatomical assessment of the coronary arteries, helping identify coronary atheroma, estimate the degree of stenosis, and in many patients rule out significant epicardial coronary artery disease. CTCA is particularly useful because it has a high negative predictive value, so a normal scan makes obstructive coronary disease much less likely. It does not directly measure ischaemia in the way functional tests do, but it is excellent for defining coronary anatomy and guiding whether further investigation, medical therapy, or referral for invasive angiography is needed.

🔥 Precipitants / Aggravating Factors

• Physical exertion
• Emotional stress
• Cold exposure
• Post-prandial exertion
• Anaemia, tachyarrhythmia, fever, thyrotoxicosis

🔍 Differentials

• Acute coronary syndrome
• Aortic stenosis
• Hypertrophic cardiomyopathy
• Gastro-oesophageal reflux disease
• Musculoskeletal chest pain
• Pulmonary causes such as pulmonary embolism

🧪 Investigations

• 12-lead ECG as part of initial assessment, though it may be normal.
• Blood tests to look for contributory conditions such as anaemia and to assess cardiovascular risk.
• CT coronary angiography (CTCA) is the recommended first-line anatomical test in recent-onset stable chest pain when stable angina is suspected.
• Functional imaging or invasive angiography may be needed in selected cases after CTCA or when symptoms persist.
• Do not use exercise ECG to diagnose or exclude stable angina.
• Echocardiography is useful if valve disease, cardiomyopathy, or LV dysfunction is suspected.

📈 Risk / Severity Clues

• Worsening frequency or symptoms at rest suggest unstable angina / ACS rather than stable angina.
• Poor LV function, extensive ischaemia, or high-risk coronary anatomy increase adverse-event risk.
• Always assess whether the story could represent ACS rather than chronic stable symptoms.

💊 Management

• Lifestyle and prevention: smoking cessation, exercise, weight reduction, healthy diet, and treatment of hypertension, lipids, and diabetes.
• Short-acting nitrate: offer GTN for preventing and treating episodes of angina.
• First-line anti-anginal therapy: offer either a beta-blocker or a calcium-channel blocker.
• If symptoms are not controlled, consider switching or combining these classes appropriately.
• If beta-blockers and calcium-channel blockers are contraindicated or not tolerated, consider long-acting nitrate, ivabradine, nicorandil, or ranolazine.
• Aspirin 75 mg daily may be considered after weighing bleeding risk.
• Statin therapy should be offered in line with lipid-modification guidance.
• ACE inhibitor should be considered in people with stable angina and diabetes, and continued if indicated for other conditions.

🔧 Revascularisation

• Consider PCI or CABG if symptoms are not satisfactorily controlled with optimal medical treatment.
• Offer coronary angiography to guide the revascularisation strategy when invasive treatment is being considered.
• The choice between PCI and CABG depends on coronary anatomy, comorbidity, symptom burden, and MDT/cardiology assessment.

💡 Clinical Pearls

• Stable angina is predictable and exertional; unstable angina is new, worsening, or occurs at rest and should be treated as ACS until proven otherwise.
• Exercise treadmill testing is no longer the recommended diagnostic test for suspected stable angina in NICE guidance.
• Microvascular angina is a real ischaemic syndrome even when the major coronary arteries look normal.

📚 References

• NICE CG95: Recent-onset chest pain of suspected cardiac origin: assessment and diagnosis.
• NICE CG126: Stable angina: management.
• British Heart Foundation: Microvascular angina.