Stable Angina (Ischaemic Heart Disease)

Retrosternal chest discomfort lasting up to 10 minutes, subsiding promptly with rest, triggered by exercise or emotional distress. Considered stable if the symptom pattern hasn’t changed in the last month.

History

Retrosternal pain radiating to the arms, jaw, or back — may be associated with shortness of breath, nausea, light-headedness, or sweating. Occurs during intense emotion, exercise, or after meals; relieved within a few minutes by rest.

Examination

Normal except when symptomatic (rarely captured in the office).

Investigations

• ECG — usually normal in the absence of symptoms.
• Exercise ECG — shows classic changes, but only ~68% sensitive, so many cases are missed.
• Stress echocardiogram — better sensitivity than exercise ECG alone.
• Nuclear perfusion study — false positives and radiation exposure are a concern.
• CT coronary angiogram (CTCA) — good negative predictive value (generally needs a heart rate < 60).
• Coronary angiogram — gold standard, but invasive.

Management

Acute treatment

Advise the patient to stop activity as soon as chest pain starts. To shorten an episode: GTN spray 400mcg SL, repeated every 5 minutes if pain persists, to a maximum of 3 doses. Call an ambulance if pain lasts to 10 minutes (give the 3rd GTN dose at this point). Adverse effects: orthostatic hypotension, headache.

Preventative treatment

Aims to reduce myocardial oxygen demand — in addition to treatment of coronary artery disease (aspirin + statin) and blood pressure. Use two anti-anginal therapies from different classes: beta-blocker, non-dihydropyridine calcium channel antagonist, and/or a long-acting nitrate. For established IHD, the LDL-C target is now <1.4mmol/L and ≥50% reduction from baseline — add ezetimibe, then a PCSK9 inhibitor, if not met on the maximally tolerated statin.

Beta-blocker: atenolol 25–100mg daily, or metoprolol 25–100mg. If LV dysfunction (EF < 40%), use a heart-failure-indicated beta-blocker instead — carvedilol, bisoprolol, nebivolol, or metoprolol succinate.

Non-dihydropyridine CCB: diltiazem 180–360mg daily, or verapamil 120–480mg daily. Don’t use if LVEF < 40%.

Long-acting nitrates: GTN patch 5–15mg transdermally for 14hrs/day, or isosorbide mononitrate 30–120mg daily.

Other options: nicorandil 5mg BD; perhexiline (treatment of last resort, needs specialist input); ivabradine.

Reduce modifiable risk factors: blood pressure, smoking, dyslipidaemia, exercise, obesity, diabetes. Vaccinate: influenza, pneumococcus at 65.

Interventional cardiology

Stenting is indicated for significant coronary artery occlusion (usually > 50% stenosis on angiogram, in a region consistent with ECG changes). CABG is indicated for significant coronary artery disease not amenable to stenting.