Coronary angiography and stents, a patient guide

Why the test is done

Coronary angiography shows the arteries supplying the heart muscle directly, and remains the most detailed way of doing so. It is used when non-invasive assessment has not answered the question, when symptoms are severe or unstable despite medication, when a heart attack is occurring, and when treatment is being planned.

Increasingly, CT coronary angiography is performed first for stable chest pain, and invasive angiography is reserved for those in whom treatment is likely or the picture is unclear.

Before the procedure

You will be asked about allergies, kidney function, diabetes medication and any blood-thinning treatment. Specific instructions about which medicines to take or hold, and about fasting, are given by the team performing the procedure and should be followed rather than assumed. Arrangements for someone to take you home afterwards are usually needed.

What happens

You lie on a table beneath an X-ray camera, awake, usually with light sedation. Local anaesthetic is injected over the artery at the wrist or, less often, at the top of the leg. A short tube is placed in the artery, and through it a fine catheter is guided to the heart. Passing the catheter through the vessels is not felt.

Contrast is injected into each coronary artery and X-ray images are recorded. Many people notice a brief warm sensation. The images show where narrowings are, how tight they are and how the arteries are arranged. The diagnostic part usually takes twenty to thirty minutes.

If a narrowing needs treating

Where a significant narrowing is found and treatment is appropriate, angioplasty can often follow immediately. A fine wire is passed across the narrowing, a balloon is inflated to open it, and a stent is deployed to hold the artery open. Brief chest discomfort during balloon inflation is common and settles as the balloon is deflated.

Modern stents are drug-eluting: the metal is coated with medication released slowly to reduce the chance of the artery re-narrowing. Sometimes pressure wire measurements or intravascular imaging are used to judge whether a narrowing is genuinely limiting flow before deciding to treat it.

Not every narrowing should be stented, and not every pattern of disease is best treated this way. Where disease is extensive, bypass surgery may offer a better result, and that discussion normally involves a heart team.

Afterwards

The tube is removed and pressure applied, with a band on the wrist for a few hours. Wrist access usually allows you to sit up and walk relatively soon. Groin access requires lying flat for longer. A diagnostic procedure alone may allow discharge the same day; after stenting an overnight stay is common.

Antiplatelet medication is prescribed after a stent, typically two agents for a defined period followed by one indefinitely. This is essential: stopping early significantly increases the risk of the stent blocking, and any planned surgery or dental work should be discussed with your cardiologist rather than managed by pausing treatment.

Bruising at the access site is normal. Most people return to routine activity within a week, with advice about heavier exertion and driving given individually.

Being clear about what a stent achieves

In an evolving heart attack, opening the blocked artery quickly limits damage and saves lives. In stable coronary disease the picture is different: stents are effective at relieving angina that persists despite medication, but it is statins, blood pressure control, antiplatelet treatment, stopping smoking and physical activity that reduce the risk of future events. Both parts of the treatment matter, and they do different things.