Stents are permanent mesh tubes that help direct blood flow to the heart or other organs. Usually, stents are not replaced but may be reinforced. However, some people may experience issues such as in-stent restenosis or thrombosis.

Restenosis is when the blood vessel with the installed stent narrows again. It can occur for many reasons, including plaque or scar tissue buildup. This could potentially affect how the stent works. If this happens, another stent may be fitted.

Certain factors, such as stent type, lesion location, patient profile, or procedural characteristics, may increase the risk of restenosis.

This article explains if and when stent replacement becomes necessary.

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Stents are permanent, according to the British Heart Foundation.

Stents are made of materials meant to keep an artery open permanently, and they should last a lifetime. However, stents alone do not cure the underlying disease that may have caused the artery to narrow in the first place. It only opens a blood vessel to help improve blood flow to the heart muscle or organ.

Learn more about coronary heart disease.

The following can occur:


Restenosis refers to a condition that can occur after a stent is inserted. With restenosis, the artery with the installed stent weakens or narrows once again. It can occur for different reasons but usually involves scar tissue or plaque formation in or around the stent.

It can take 6 months for restenosis to occur, according to the U.K.’s National Health Service (NHS).


A blood clot can occur within the stent. It’s an event known as in-stent thrombosis.

In-stent thrombosis can occur when a person does not take blood clotting medication or make certain lifestyle changes — both are measures to help prevent plaque buildup. If the artery closes completely, the person may have a heart attack. This is a medical emergency.

Many factors may increase the risk of restenosis. This can include stent-related factors, such as:

  • stent type
  • size of the stented blood vessel
  • length of the stent

Other risk factors for restenosis include:

The risk of in-stent restenosis is also higher in people who have multiple blocked vessels.

Prior to the introduction of stents, the risk of restenosis was high, at about 32–55%. These rates have dropped significantly with improvements in technology. Generally, newer stents have helped lower the risk of restenosis and the need for stent replacements. Examples of newer-generation stents include:

  • bare-metal stents
  • drug-eluting stents
  • drug-coated balloons

Interestingly, drug-coated balloons can treat in-stent restenosis in certain people. This may serve as an alternative to traditional stent replacement procedures. A major advantage of using a drug-coated balloon for stent restenosis is that no new mesh is required.

If symptoms of angina return, seek help immediately. Angina symptoms may not be as severe as before the stent was inserted. The person may have angina during effort-required tasks. They may have angina less frequently at rest, a condition called unstable angina.

Any symptoms of in-stent thrombosis, which can be as severe as a heart attack, require immediate medical attention.

While the likelihood of restenosis is rare with stent placement, per the British Heart Foundation, another blood vessel may become blocked and require attention.

When stent replacement is necessary, experts may recommend placing another stent in its place as quickly as possible.

Some of the risks associated with stent procedures include:

  • allergic reactions to any materials used during the procedure
  • irregular heartbeat (arrhythmia)
  • bleeding where the catheter was inserted
  • blood vessel damage
  • infection
  • heart attack
  • stroke
  • kidney damage due to the contrast dye used in the procedure

They can also be fatal.

Below are some frequently asked questions about stent replacement:

How do I know my stent is blocked?

People may notice symptoms returning if the stent becomes blocked or has issues. In general, symptoms may vary depending on where the stent was placed initially. For example, if stent blockage occurs in the coronary arteries, chest pain or angina symptoms may come back.

How often should a stent be checked?

How often a stent needs checking can vary and may depend on factors such as stent type or a person’s overall health status.

As a point of reference, in the first year of stent placement, a person may expect follow-up appointments every 3–6 months. During appointments, a doctor may review medications. The person can also discuss new symptoms (if any) or other concerns they may have.

Can you live a long life with a stent in your heart?

Yes, living a long life with a stent in the heart is possible. However, a person must manage their heart health effectively. This includes:

  • making some lifestyle changes — such as quitting smoking (if applicable)
  • taking prescribed medications
  • staying physically active
  • managing underlying health conditions

Stents are permanent but may need to be reinforced in case of restenosis.

Individual risk factors that may increase the likelihood of restenosis include sex, diabetes, and specific measures of heart function. Stent characteristics, such as the stent length and type, may also increase the chances of restenosis.

Restenosis may cause angina symptoms to return.

People are encouraged to adhere to routine follow-ups with their cardiologist to help prevent restenosis. The cardiologist can monitor the stent through medical imaging.

Stents do not cure diseases that cause artery narrowing. Following heart-healthy lifestyle habits are necessary to manage underlying medical conditions.