Mostly from clinical history characterized by chest pain due to myocardial ischaemia usually inducible by exercise, emotion or other stress and reproducible, relieved by rest but may occur spontaneously and stable in nature.

Pharmacological

• A: Acetylsalicylic acid (soluble) 75–150 mg PO every 24 hours, OR D: clopidogrel 75 mg PO every 24 hours if allergic to aspirin,

• AND C: isosorbide dinitrate 20–40 mg PO every 12 hours.

If nitrates cannot be tolerated, add medicines stepwise:

1. Step 1 – beta-blocker if not contraindicated: B: atenolol 12.5–25 mg every 24 hours, OR C: metoprolol succinate (SR) 25–200 mg every 24 hours, OR S: metoprolol tartrate 5 mg IV over 2 minutes (maximum 3 doses) then 50–100 mg PO every 12 hours, OR S: bisoprolol 2.5–10 mg every 24 hours.

2. Step 2 – if a beta-blocker is not tolerated or contraindicated, a long-acting calcium channel blocker or I(f) inhibitor: D: diltiazem 60 mg PO every 6–8 hours (if Prinzmetal angina is suspected), OR S: verapamil 60–120 mg PO every 8 hours, OR S: ivabradine 2.5–5 mg PO every 24 hours.

3. Step 3 – add the late sodium current blocker S: ranolazine 375–1000 mg/kg PO every 12 hours.

⚠ Dose check note: STG 2026 prints ranolazine as "375-1000 mg/kg 12hourly". Ranolazine is a fixed dose, not per kilogram: WHO-listed and standard guidance give 375–500 mg PO every 12 hours, increased to a maximum of 1000 mg every 12 hours; a per-kilogram dose would be a massive overdose. Cross-check this dose against the WHO recommendation before prescribing.

All patients with chronic stable angina are at high risk of cardiovascular events: start a statin (B: atorvastatin 20–80 mg PO every 24 hours or S: rosuvastatin 10–40 mg every 24 hours).

Indications for referral

• Angina or chest pain suggesting unstable coronary disease (unstable angina or acute coronary syndrome).

• Diagnosis in doubt or failed medical therapy, especially when no echocardiogram or skilled person is available.

When instability is likely, give before referral: A: acetylsalicylic acid 300 mg PO stat AND B: atorvastatin 80 mg PO stat AND D: clopidogrel 300 mg PO stat.

Non-pharmacological

General Measures

• Lifestyle modification: no tobacco, healthy low-fat diet, salt up to 6 g/day, alcohol within limits, 150 minutes/week of moderate exercise, BMI 18.5–24.9 kg/m².

• Annual check of lipids, glucose and creatinine in all patients with known IHD.

• Resting ECG at presentation and immediately after an episode of chest pain suggesting instability (consider immediate referral).

• Resting echocardiogram in some patients: to exclude other causes of angina, look for regional wall motion abnormalities, measure LVEF for risk stratification and assess diastolic function; refer if no echocardiography is available.

• Stress ECG or stress echocardiography (exercise, or dobutamine for patients who cannot walk on a treadmill).