Coronary angioplasty and stenting

The purpose of a coronary angioplasty is to restore or improve blood flow to the heart muscle to address coronary heart disease that can cause angina or heart attack.

Coronary angioplasty is a non-surgical procedure that does not usually require an overnight stay in hospital. It involves inflating small sausage-shaped balloons inside the coronary arteries (the arteries supplying blood to the heart muscle) that have been narrowed as a result of atherosclerosis (the build-up of fatty deposits, or plaques, in the arteries). Devices called stents are then positioned inside the artery to keep it open.

A coronary stent is a small expandable mesh tube that is positioned inside a narrowed area in an artery referred to as a stenosis (plural = stenoses), and acts as an internal scaffold to help keep the artery open. The majority of stents have a medication coated on them and are known as drug-eluting stents. Once the stent is deployed in the artery the medication is slowly released into the surrounding area to help reduce the chance of the artery re-narrowing (known as re-stenosis).

Most stents are made of metal but some drug-eluting bioabsorbable stents are made of a dissolvable polymer. Stents without a medication coating are known as bare metal stents.

Coronary angioplasty and stenting can be performed on an emergency basis during a heart attack to open a blocked or narrowed artery to restore blood flow; or they can be performed as a planned (elective) procedure.

The procedure

Coronary angioplasty and stenting are usually performed as a day-stay procedure, though sometimes an overnight stay in hospital may be required.

After admission, an electrocardiogram (a tracing of the heart’s electrical activity) and blood tests (to check kidney function and blood cell counts) will be performed. On some occasions a chest x-ray may also be taken.

Baseline measurement of the blood pressure, heart rate, and temperature will be recorded. The entry site for the procedure will be shaved. The patient cannot eat or drink anything for a few hours before the procedure.

The patient will be mildly sedated but awake during the procedure and staff will monitor heart rhythm and rate, blood pressure, and blood oxygen levels.

A narrow plastic tube (an introducer sheath) will be inserted into an artery in the wrist (radial approach) or the groin (femoral approach). A catheter (a thin flexible tube) is inserted though the introducer sheath and is positioned at the entrance to the coronary arteries. The cardiologist injects x-ray-detectable dye through the catheter into the coronary arteries, enabling them to be seen on an x-ray screen. This procedure is known as a coronary angiogram.

A specialised x-ray camera is positioned over the chest during the procedure. The camera is able to move to a number of positions so that x-ray pictures can be taken from different angles. If a narrowed area is identified, and it is deemed to be suitable for treatment with coronary angioplasty and stenting, this is usually done straight away.

A balloon-tipped catheter is passed through the introducer sheath and is threaded up into the coronary arteries. It is positioned within the narrowed portion of the artery and is checked on the x-ray screen. Once correctly positioned, the balloon is inflated. The inflated balloon opens the narrowed artery by compressing the plaque and slightly stretching the artery wall. Each balloon catheter is selected to be approximately the same size as the artery and the balloon is made to only inflate to a specific size.

A stent is deployed in a similar way. The unexpanded stent is tightly crimped on a balloon tipped catheter. The stent is positioned within the narrowed portion of the artery and the balloon is expanded, opening the stent and pushing it up against the artery wall. The balloon is then deflated and removed, leaving the stent behind to act as an internal scaffold to keep the artery open. Once the stent is in place, it cannot be removed.

Occasionally, another balloon-tipped catheter is inflated inside the stent to ensure that it is fully expanded. When the cardiologist is satisfied that the artery has been opened sufficiently, and the stent is adequately deployed, more x-ray pictures of the artery will be taken to see how blood flow through the artery has improved. The catheter is then removed.

Recovery

Following the procedure, the patient is returned to the ward and blood pressure, heart rate, and heart rhythm will be monitored. Fluids may be given through a small needle (drip) inserted into a vein in the hand or arm, which helps to flush the x-ray dye from the kidneys.

Prior to discharge a further ECG and blood tests may be taken. A doctor or nurse will advise about recovery and activity guidelines following discharge from hospital. Some activities, such as heavy lifting, should be avoided for at least a week. Land Transport Safety Authority (LTSA) guidelines prohibit driving for at least two days after a coronary angioplasty. The patient will therefore need someone to drive them home after the procedure.

Medications will be prescribed before the patient is discharged which is likely to include medications that help to prevent blood clots forming within the stent.

Complications

The risks associated with coronary angioplasty are very small. It is important to discuss these with the cardiologist prior to signing the consent form for the procedure. Risks of coronary angioplasty include:

• Abrupt closure of the coronary artery
• An allergic reaction to the x-ray dye
• Heart attack or stroke
• Damage to the coronary artery
• Damage to the catheter insertion site.

In a small percentage of cases the coronary artery narrows again soon after the angioplasty. If re-stenosis is going to occur, it usually does so within the first six months after the angioplasty is performed. In these cases, a repeat angioplasty or coronary artery bypass surgery may be recommended. In a small number of cases (about 1–2%) emergency coronary bypass surgery is necessary because of complications of the coronary angioplasty and stenting procedure.

Lifestyle changes

Although having a coronary angioplasty reduces the symptoms of heart disease it is not a cure for heart disease. Therefore, to lower the risk of experiencing future heart problems, it is important that recipients of a coronary angioplasty adopt (and maintain) lifestyle changes. These include stopping smoking, losing weight, eating a heart disease-appropriate diet, and establishing a heart disease-appropriate exercise routine.

References

Heart Foundation (2019). A guide to angioplasty (Booklet PDF). Auckland: National Heart Foundation of New Zealand. https://assets.heartfoundation.org.nz/documents/shop/heart-healthcare/coronary-angiography-and-angioplasty-2019.pdf?1605561200
Heart Foundation (Date not stated). Angioplasty and stents (Web Page). Auckland: National Heart Foundation of New Zealand. https://www.heartfoundation.org.nz/your-heart/heart-treatments/angioplasty-and-stents [Accessed: 18/11/20]
NHS (2018). Coronary angioplasty and stent insertion (Web Page). Redditch: National Health Service (NHS)England. https://www.nhs.uk/conditions/coronary-angioplasty/ [Accessed: 18/11/20]
Stouffer, G.A. (2019). Percutaneous coronary intervention (PCI) (Web page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. https://emedicine.medscape.com/article/161446-overview [Accessed: 18/11/20]

Last Reviewed: November 2020

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