A narrowing of the coronary arteries reduces blood flow to the myocardium (heart muscle). During times of high demand such as exercise there is insufficient supply of blood to meet demand. This causes symptoms the symptoms of angina, typically constricting chest pain with or without radiation to jaw or arms. Angina is “stable” when symptoms are always relieved by rest or glyceryl trinitrate (GTN). It is “unstable” when the symptoms come on randomly whilst at rest, and this is considered as an Acute Coronary Syndrome.
CT Coronary Angiography is the Gold Standard diagnostic investigation. This involves injecting contrast and taking CT images timed with the heart beat to give a detailed view of the coronary arteries, highlighting any narrowing.
All patients should have the following baseline investigations:
- Physical Examination (heart sounds, signs of heart failure, BMI)
- FBC (check for anaemia)
- U&Es (prior to ACEi and other meds)
- LFTs (prior to statins)
- Lipid profile
- Thyroid function tests (check for hypo / hyper thyroid)
- HbA1C and fasting glucose (for diabetes)
The management described here is based on 2018 NICE CKS on Angina and 2018 SIGN guidelines. There are four principles to management (RAMP):
- R – Refer to cardiology (urgently if unstable)
- A – Advise them about the diagnosis, management and when to call an ambulance
- M – Medical treatment
- P – Procedural or surgical interventions
There are three aims to medical management:
- Immediate Symptomatic Relief
- Long Term Symptomatic Relief
- Secondary prevention of cardiovascular disease
Immediate Symptomatic Relief
- Their GTN spray is used required. It causes vasodilation and helps relieves the symptoms.
- Take GTN, then repeat after 5 minutes. If there is still pain 5 minutes after the repeat dose – call an ambulance.
Long Term Symptomatic Relief is with either (or used in combination if symptoms are not controlled on one):
- Beta blocker (e.g. bisoprolol 5mg once daily) or;
- Calcium channel blocker (e.g. amlodipine 5mg once daily)
Other options (not first line):
- Long acting nitrates (e.g. isosorbide mononitrate)
- Aspirin (i.e. 75mg once daily)
- Atorvastatin 80mg once daily
- ACE inhibitor
- Already on a beta-blocker for symptomatic relief.
Procedural / Surgical Interventions
Percutaneous Coronary Intervention (PCI) with coronary angioplasty (dilating the blood vessel with a balloon and/or inserting a stent) is offered to patients with “proximal or extensive disease” on CT coronary angiography. This involves putting a catheter into the patient’s brachial or femoral artery, feeding that up to the coronary arteries under xray guidance and injecting contrast so that the coronary arteries and any areas of stenosis are highlighted on the xray images. This can then be treated with balloon dilatation followed by insertion of a stent.
Coronary Artery Bypass Graft (CABG) surgery may be offered to patients with severe stenosis. This involves opening the chest along the sternum (causing a midline sternotomy scar), taking a graft vein from the patient’s leg (usually the great saphenous vein) and sewing it on to the affected coronary artery to bypass the stenosis. The recovery is slower and the complication rate is higher than PCI.
TOM TIP: When examining a patient that you think may have coronary artery disease, check for a midline sternotomy scar (previous CABG), scars around the brachial and femoral arteries (previous PCI) and along the inner calves (saphenous vein harvesting scar) to see what procedures they may have had done and to impress your examiners.
Last updated October 2018