Coronary angioplasty is a treatment to widen narrowed sections of the coronary arteries.
What is coronary angioplasty used for?
Coronary angioplasty is commonly used to treat people who have angina or breathlessness resulting from a narrowing in one or more of their coronary arteries. Angioplasty can also be used to help in emergency situations, such as when a person has a heart attack.
What is angina and what causes it?
The heart is a muscle that pumps blood into blood vessels which take the blood to every part of the body. Like any other muscle, the heart muscle needs a good blood supply and the coronary arteries take blood to the heart muscle.
Angina is a pain that comes from the heart. It is caused by an imbalance between the supply and demand of blood required by heart muscle. The most common cause of angina is a narrowing of one or more of the coronary arteries. This reduces the blood supply to a part of heart muscle. The blood supply may be enough under resting conditions but when the heart muscle needs more blood and oxygen to work harder, the extra blood supply required cannot get past the narrowed arteries. Therefore under physical exertion such as walking fast or climb stairs, the heart ‘complains’ with pain. This is the symptom of angina.
The narrowing of the arteries is caused by atheroma. Atheroma is fatty ‘plaques’ of cholesterol that develop within the inside lining of arteries, similar to water pipes that get ‘furred up’ with limescale. Plaques of atheroma may gradually form over a number of years in one or more places in the coronary arteries. In time, these can increase in size and cause enough narrowing of one or more of the arteries to cause symptoms.
How is coronary angioplasty done?
This procedure can be performed via the wrist or the groin. Dr Jagathesan prefers to undertake these procedures via the wrist in order to reduce recovery time and post procedural complications.
You lie on a couch in a catheterisation room. An X-ray machine is mounted above the couch. A thin, flexible ‘guide’ tube (catheter) is inserted through a wide needle or small cut in the skin into a blood vessel in the groin or arm. Local anaesthetic is injected into the skin above the blood vessel, so it should not hurt when the catheter is passed into the blood vessel.
The tip of the catheter is advanced to the heart under X-ray monitoring up to the coronary artery where there is narrowed section caused by the fatty patches or ‘plaques’ (atheroma). A guide wire is then passed down this guide catheter into the coronary artery that is being treated. Then a ‘balloon catheter’ is then passed down over the ‘guide’ wire to the obstruction. The balloon is then blown up for 15-30 seconds squashing the atheroma and widening the narrowed artery. Following this the balloon catheter is withdrawn and the process repeated with a balloon catheter that has a stent preloaded onto the balloon. During this balloon inflation the stent is deployed into the vessel. The stent is like a wire mesh tube which acts as a type of scaffolding and gives support to the artery helping to keep the artery widened. The procedure may be repeated for one or more other narrowed sections within the coronary arteries.
You cannot feel the catheter inside the blood vessels. You may feel an occasional missed or extra heartbeat during the procedure. This is normal and of little concern. When the balloon is blown up it stops the blood flow. Therefore, you may get an angina-like pain for a short time. However, this soon goes after the balloon is let down. A sedative can be given for the procedure if you are anxious.
After the procedure you are monitored for a number of hours and occasionally overnight. After an angioplasty you should avoid any heavy activities such as lifting for about a week until the small wound, where the thin, flexible tube (catheter) was inserted, has healed. You should not drive a car for a week after having an angioplasty. If you have an LGV or PCV licence, you should check with the DVLA about driving a bus or lorry following an angioplasty.
How do I prepare for a coronary angioplasty?
You should get instructions from your local hospital about what you need to do. The sort of instructions may include:
- If you take any ‘blood-thinning’ medicine such as warfarin or another anticoagulant, you will need to stop this for 2-3 days before the test (to prevent excessive bleeding from the site of the thin, flexible tube (catheter) insertion).
- If you take insulin or medicines for diabetes, you may need to alter the timing of when you take these. Some medicines may need to be stopped for 48 hours. Your doctor should clarify this with you.
- You may be asked to stop eating and drinking for 4-6 hours before the procedure.
- You may be asked to shave both groins before the procedure.
- You will have to sign a consent form at some point before the test to confirm that you understand the procedure, understand the possible complications (see below), and agree to the procedure being done.
How successful is coronary angioplasty?
More than 9 in 10 procedures are successful at relieving angina. However, coronary angioplasty cannot be used for all people with angina. This is because in many cases there are too many narrowed sections in the heart arteries, or the dieseased segments are too long, or too narrow, or too far down a coronary artery or branch artery for this procedure.
Sometimes it is not possible to stretch the narrowed artery. An alternative treatment for angina called coronary artery bypass grafting may then be an option. However, most people feel that it was worth trying an angioplasty first. This is because, unlike bypass grafting, it does not involve major surgery.
In some cases, scar tissue forms within the small tube (stent) over the next few months and years. This may narrow the artery again and angina pains may return. If it does, then the procedure can be repeated, or other treatments for angina can be considered, such as coronary artery bypass grafting.
Newer techniques are being developed to try to prevent this possible problem. For example, stents that are coated with chemicals which prevent the local formation of atheroma are currently in use that reduce this risk of re-narrowing to as low as 2-3%.
Risks of the procedure
In the vast majority of cases, there are no serious problems. However, you have to accept the risk that in some cases problems do arise:
- The small wound where the small, flexible tube (catheter) is inserted sometimes becomes infected. A short course of antibiotics will usually deal with this if it occurs.
- Rarely, some people have an allergic reaction to the dye. This can be treated with a short course of medication
- Serious complications are rare, but do sometimes occur. The risk is mainly in people who already have serious heart disease. Potential serious complications include:
Occlusion or dissection of the coronary artery. Usually this complication can be treated with the catheter and balloon. Occasionally, this may cause a heart attack during the procedure and in rare cases urgent coronary artery bypass graft operation is necessary (which is usually successful).
A stroke is another rare complication.
Very rarely, some people die during this procedure as a consequence of one of these serious complications.