The heart pumps blood around the body, but its muscle also needs its own oxygen-rich blood. Coronary arteries branch over the surface of the heart and supply that muscle. A build-up of fatty material in an artery wall, called atherosclerosis, can narrow the channel through which blood flows. A narrow artery may struggle to meet the heart’s demand, especially during exertion.

Angina is discomfort caused by reduced blood supply to heart muscle. Stable angina often follows a recognisable pattern, such as discomfort brought on by activity and eased by rest or prescribed medicine. In a heart attack, blood supply is suddenly interrupted, often when a clot forms at a damaged plaque. The longer the interruption continues, the more heart muscle can be injured. Symptoms and treatment choices need clinical assessment, not a diagnosis from the pattern alone.

For stable angina, the aim of PCI is often to improve symptoms and daily activity when medicine has not controlled symptoms adequately or is unsuitable. Assessment considers the story of your symptoms, tests and the location and extent of narrowing. NICE recommends medicines for symptoms and prevention, with revascularisation, restoring blood supply, considered when symptoms are not satisfactorily controlled with optimal medical treatment.

In an acute coronary syndrome, including a heart attack, the goal and urgency can be different. Emergency PCI can reopen a blocked artery and restore blood supply. NICE recommends primary PCI as the preferred treatment for eligible people with a type of heart attack called STEMI when it can be delivered within the recommended time; clot-dissolving medicine may be considered when timely primary PCI cannot be provided. Other heart attack presentations are assessed and treated according to their risk and circumstances.

An angiogram is an X-ray test that shows the coronary arteries using contrast dye. It helps the team identify narrowing, but it does not automatically mean a stent is necessary. Your team may use further tests to understand blood flow and decide whether a narrowing is responsible for symptoms. Ask what the findings show and what each treatment is intended to achieve for you.

Medicines can reduce angina and help lower the risk of future cardiovascular events. Depending on your situation, these may include medicines for angina, antiplatelets, cholesterol-lowering treatment and medicines for blood pressure. The right combination depends on your health and tolerance. PCI treats a particular narrowing; it does not remove the underlying tendency for disease elsewhere, so medicines and risk reduction often remain important afterwards.

Coronary bypass surgery uses a blood vessel graft to route blood around a blocked or narrowed coronary artery. PCI approaches the narrowing from inside the artery using a catheter; bypass is heart surgery and has a different recovery. The location and complexity of disease, other health conditions, possible benefits and risks, and your preferences help determine which option is appropriate. Some people are better suited to bypass or medicines. Ask whether a specialist heart-team discussion would help.

Valve replacement treats a diseased heart valve, which controls blood flow through the heart. It is a different procedure from widening a coronary artery. Some people have more than one heart problem, so ask which condition each proposed treatment addresses and whether treatments need to be coordinated.

Opening a suitable narrowing can improve blood flow, and many people find that angina improves. Improvement is not guaranteed: symptoms may persist or return, including if other arteries are affected or the treated area narrows again. Ask the team how likely relief is in your situation and what they expect if you choose medicines instead.

The ORBITA-2 trial randomly assigned 301 selected people with stable angina and evidence of reduced blood flow to PCI or a placebo procedure. At 12 weeks, the PCI group had a better angina symptom score. Participants had little or no antianginal medication during the trial and most were men. The result supports symptom benefit in this selected group; it does not establish a long-term survival benefit or predict the result for every patient. The emergency heart attack situation is different.

For planned PCI, the team reviews your symptoms, tests, medical history and medicines. Mention allergies or a previous reaction to contrast dye, kidney problems, diabetes, pregnancy or possible pregnancy, and any prior bleeding. Bring a current list of prescribed and over-the-counter medicines, supplements and allergies. Ask for individual instructions on diabetes medicines, anticoagulants and antiplatelets. Do not stop or change them on your own.

Follow your hospital’s own instructions about eating, drinking and medicines before arrival. Arrange a lift home and support for the first day if needed. Ask about the expected stay, time off work and whom to contact if you become unwell before the procedure. In an emergency there may be little time to prepare; tell the team what you can about your health and medicines.

Before a planned procedure, ask the clinician to explain the expected benefit, meaningful risks and reasonable alternatives, and what might change the plan. You can bring someone to the discussion or ask for information in another format. Emergency treatment may need faster decisions, but you can still ask what is happening and why.

PCI usually takes place in a cardiac catheterisation laboratory. You are usually awake, with local anaesthetic to numb the access site; a sedative may be offered to help you relax. A clinician inserts a short tube into an artery, commonly at the wrist or sometimes the groin, and guides a thin catheter towards the coronary arteries. Heart rhythm and other observations are monitored throughout.

Contrast dye and X-ray images show the arteries. A fine guidewire is passed across the narrowing, and a small balloon is inflated to widen it. Usually a small metal mesh tube, a stent, is expanded at the site. The balloon and catheter are removed but the stent stays in place as a scaffold. Many stents release medicine to reduce the chance of the artery narrowing again. The team may use additional techniques for difficult or heavily calcified narrowing.

You may feel pressure, warmth from the dye or temporary chest discomfort when the balloon is inflated. Tell the team straight away about chest pain, breathlessness or feeling unwell. After the catheter is removed, pressure or a device helps seal the access site. Nurses monitor you and check for bleeding; groin access may mean lying flat for a period. The exact sequence and duration depend on the situation.

Bruising or bleeding at the wrist or groin is common. Infection or injury to the access artery can occur. Less common serious complications include heavy bleeding requiring transfusion, an allergic reaction to contrast, damage to a coronary artery, heart attack, stroke or death. Risk varies with age, overall health, other conditions and whether PCI is planned or an emergency. Your team can explain the risks relevant to you.

Contrast can affect kidney function, especially in people already at risk; tell the team about kidney disease and ask what precautions or monitoring are appropriate. A clot can form inside a stent, and the treated area can also become narrowed again over time. These are different problems: a sudden clot can block blood flow, while re-narrowing can bring back angina. Both need clinical assessment.

After planned, uncomplicated PCI, many people go home the same day or the next day. A heart attack or complications can mean a longer stay. Before leaving, make sure you understand the written discharge advice, medicines, wound care and the contact number for the unit. A small bruise or tenderness at the access site is common, but watch for the warning signs above.

NHS England advises avoiding heavy lifting and strenuous activity for about a week or until the wound heals. Ask about your particular access site, work, exercise and sexual activity. Recovery after a heart attack often takes longer than recovery from a planned procedure. Ask about cardiac rehabilitation: it can offer supervised support, information and a plan for returning to everyday activity.

NHS England advises not driving a car for a week after angioplasty. Longer restrictions may apply after a heart attack or complications, and the rules differ for bus and lorry licences. Ask your team when you are fit to drive and check current DVLA requirements, or the relevant licensing authority in Northern Ireland. Check with your insurer as well.

After a stent, antiplatelet medicines reduce the risk of platelets forming a clot in or around it. Many people take two together for a period, often aspirin plus clopidogrel, prasugrel or ticagrelor. The combination and duration depend on the reason for PCI, bleeding risk and other treatment. Some people also need an anticoagulant for another condition; the specialist team must balance clotting and bleeding risks.

Take each medicine exactly as prescribed and arrange repeat supplies before you run out. Do not stop either antiplatelet independently, even if you feel well: stopping early can greatly increase the risk of a clot and heart attack. If you miss a dose, cannot take it, have side effects or are worried about bleeding, contact your pharmacist, GP or cardiac team promptly for advice. Tell a dentist or any clinician planning another procedure that you have a stent and take antiplatelets, so teams can coordinate any changes.

Antiplatelets can increase bleeding. Blood in urine or stool, vomit containing blood or resembling coffee grounds, a growing bruise or a nosebleed that will not stop needs urgent medical help. Call 999 for a life-threatening emergency.

PCI does not cure coronary artery disease. Continue other prescribed treatment and discuss cholesterol, blood pressure, diabetes, stopping smoking, movement and food choices with your team. Ask about follow-up and what to do if angina returns or your activity becomes limited again. A future narrowing may require reassessment and sometimes further treatment.