Stable angina

Overview

•Central chest pain - heavy/tight, brought on by exertion, cold, emotional stress, or large meal
•Radiation - left arm, jaw, neck, shoulder, or epigastrium
•Relief - resolves within 2-5 minutes of rest or sublingual GTN; if not, consider alternative diagnosis
•Reproducible - same exertion threshold reliably triggers symptoms; patient can predict onset
🚨
Distinguish stable from unstable: pain at rest, pain on minimal exertion (e.g. getting dressed), or rapidly progressive symptoms = unstable angina - admit urgently.

Investigations

🥇 First-line

•CT coronary angiogram (CTCA) - non-invasive, directly visualises coronary stenoses; recommended by NICE for all patients with stable chest pain of suspected CAD origin
•Resting 12-lead ECG - often normal in stable angina; may show ST/T-wave changes or prior MI evidence
•Bloods - FBC, fasting lipids, HbA1c/glucose, renal function, TFTs

🥈 Second-line

•myocardial perfusion imaging or stress echocardiography - if CTCA non-diagnostic

🏆 Gold standard

•invasive coronary angiography - reserved for likely intervention (PCI/CABG) or inconclusive non-invasive tests; allows simultaneous revascularisation
🎯
The exercise treadmill test is no longer recommended as first-line investigation for stable chest pain in UK practice (NICE CG95) - CTCA has superseded it. This distinction is directly tested.

Management

•Acute relief (all patients): sublingual glyceryl trinitrate (GTN) 400 micrograms spray - also use prophylactically 5 minutes before planned exertion
Step 1 · Monotherapy
  1. 1Start beta-blocker (e.g. bisoprolol) OR rate-limiting CCB (verapamil or diltiazem) as monotherapy
  2. 2Titrate to maximum tolerated dose before adding a second agent
If on beta-blocker and symptoms persist
Add long-acting dihydropyridine CCB - amlodipine or modified-release nifedipine. NEVER add verapamil or diltiazem to a beta-blocker.
If on rate-limiting CCB and symptoms persist
Add beta-blocker OR switch to long-acting dihydropyridine CCB + beta-blocker combination
Step 2 · Combination therapy fails
  1. 1Add third agent: isosorbide mononitrate (long-acting nitrate) - use asymmetric dosing to maintain 10-14 hour nitrate-free period to prevent tolerance
  2. 2Alternatives: nicorandil (nitrate + potassium channel activator) or ivabradine (HCN channel blocker, rate-reducing) or ranolazine (sodium channel inhibitor)
Step 3 · Refractory symptoms
  1. 1Refer to cardiology for invasive angiography to assess suitability for PCI or CABG
⚠️
Never combine a rate-limiting CCB (verapamil or diltiazem) with a beta-blocker - both reduce AV node conduction, risking severe bradycardia, complete heart block, or heart failure. When adding a CCB to a beta-blocker, always choose a dihydropyridine (amlodipine or modified-release nifedipine).

Secondary prevention

•Aspirin 75mg daily - all patients; use clopidogrel 75mg daily if aspirin not tolerated
•Atorvastatin - high-intensity statin for all patients with atherosclerotic stable angina (NICE CG181)
•ACE inhibitor (e.g. ramipril) - prescribe for coexisting hypertension, heart failure, LV dysfunction, CKD, prior MI, or diabetes
💡
Symptom control does not equal improved survival - statin, aspirin, and ACE inhibitor are the interventions with proven mortality benefit. PCI does not reduce mortality in stable CAD vs optimal medical therapy but reduces angina burden. CABG may confer survival benefit in left main stem disease, three-vessel disease, or impaired LV function.