CAD: In-Stent Restenosis

People who undergo angioplasty and stenting to treat coronary artery disease may develop in-stent restenosis. Scar tissue forms under the stent, causing a previously opened coronary artery to narrow again. You need another angioplasty or heart bypass surgery to correct the problem. The use of drug-eluting stents decreases the risk of restenosis.


What is in-stent restenosis?

Stenosis is the medical term for the narrowing of a blood vessel. Healthcare providers perform a procedure called angioplasty to treat coronary artery disease (CAD). During an angioplasty, they may place stents (tiny wire mesh tubes) to open the blocked arteries due to CAD. These treatments allow blood to flow more freely through the artery. When the treated, opened artery closes up again, this is restenosis. In-stent restenosis is a blockage or narrowing that comes back in the portion of the coronary artery previously treated with a stent.

What are the coronary arteries and coronary artery disease (CAD)?

Normally, your heart’s blood supply comes from two arteries called the left and right main coronary arteries. These cardiac blood vessels supply oxygenated blood to your heart. Coronary artery disease (CAD) occurs when fatty deposits called plaque build up in one or both arteries and their branches. Plaque makes the arteries too narrow, which slows blood flow to your heart.

CAD is a type of atherosclerosis or arterial disease. You may also hear the term “hardening of the arteries.” The plaque buildup happens gradually and may not cause noticeable symptoms. Untreated arterial disease can lead to life-threatening cardiovascular disease, heart failure, heart attack or stroke.

What is angioplasty?

Angioplasty is a percutaneous interventional procedure to open a blocked or narrowed artery. Percutaneous coronary intervention (PCI) is when your healthcare provider performs angioplasty on a coronary artery. “Percutaneous” means the procedure takes place through a small opening in your skin. Your healthcare provider threads a catheter (thin, flexible tube) through a blood vessel. A balloon device at the tip of the catheter inflates at the site of the blockage to expand the artery. Providers often place a stent inside the artery to keep it open, improving blood flow.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

How common is in-stent restenosis?

About 1 in 4 people who undergo angioplasty with stenting develop in-stent restenosis. This tends to happen three to six months after the procedure. Restenosis is even more likely to occur when you don’t get a stent. About 4 in 10 people who undergo balloon angioplasty without stenting experience restenosis.

Symptoms and Causes

What causes in-stent restenosis?

After angioplasty and stenting, tissue grows over the stent to form a new lining for the artery wall. This lining allows blood to flow smoothly, lowering the chances of a blood clot forming within the stent. It’s not uncommon for some scar tissue to form underneath this lining. But when there’s too much scar tissue, the lining of the artery can get too thick and slow blood flow again. In-stent restenosis typically occurs within three to six months after treatment. It’s unlikely to occur later than that.


Who is at risk for in-stent restenosis?

Anyone who gets angioplasty and stenting to treat CAD can develop in-stent restenosis. However, these factors can increase your risk:

What are the symptoms of in-stent restenosis?

Many people with in-stent restenosis don’t have symptoms. Some people experience a type of chest discomfort or pressure called angina. Physical activity or exertion can bring on this chest discomfort.

When symptoms occur, they’re often similar to CAD symptoms. You may experience:


Diagnosis and Tests

How is in-stent restenosis diagnosed?

In-stent restenosis doesn’t always cause symptoms. That’s why it’s important to see your healthcare provider for regular checkups after having an angioplasty and stenting.

If you have symptoms, your healthcare provider may recommend tests like:

Management and Treatment

How do providers treat in-stent restenosis?

Depending on how severe the in-stent restenosis is, your healthcare provider will determine which treatment is right for you. Your healthcare provider may recommend one of these treatments:

  • Medications: Your provider might increase or add medications to help with symptoms related to the in-stent restenosis.
  • Repeat angioplasty: To open the blocked artery, this sometimes will require another stent.
  • Heart bypass surgery: This surgical procedure is also called coronary artery bypass grafting or CABG. It uses a transplanted artery to send blood flow around the blockage.
  • Vascular brachytherapy: Radiation therapy is effective for different types of cancers; however, it can also treat a blocked artery. You may hear it called coronary brachytherapy.


Can you prevent in-stent restenosis?

In-stent restenosis is less likely to occur with drug-eluting stents. Unlike bare metal stents, these stents have a thin coating of medication that helps to prevent scar formation inside of the stent.

In the early 2000s, there were concerns that drug-eluting stents increased the risk of heart attacks. But newer versions are safe and effective. Fewer than 1 in 10 people who get drug-eluting stents develop in-stent restenosis.

Outlook / Prognosis

What is the outlook for someone with in-stent restenosis?

People who develop in-stent restenosis may be more prone to life-threatening heart problems. These can include unstable angina, acute coronary syndrome and heart attacks. Fortunately, newer stents and improved ways of placing stents are lowering these risks.

If you have CAD, you should follow your provider’s recommendations to protect your heart. You may need to:

Living With

When should I call the doctor?

Call 911 if you think you’re having a heart attack. If you’ve had angioplasty and stenting, you should call your provider if you experience:

  • Chest discomfort (angina), arm pain or shoulder pain.
  • Cold sweats.
  • Shortness of breath.
  • Unexplained fatigue or weakness.

What should I ask my provider?

You may want to ask your healthcare provider:

  • What caused the restenosis?
  • Can I get restenosis again?
  • What steps should I take to protect my heart?
  • Should I look for signs of complications?

A note from Cleveland Clinic

Angioplasty and stenting are life-saving procedures that can improve blood flow to your heart. After this treatment for coronary artery disease (CAD), you should have more energy and CAD symptoms should disappear. Symptoms like fatigue, chest pain or shortness of breath can indicate in-stent restenosis. If you experience symptoms, you should contact your healthcare provider. Newer, safer drug-eluting stents can lower your risk of developing in-stent restenosis. Talk to your provider about whether a drug-eluting stent is right for you.

Medically Reviewed

Last reviewed on 07/20/2022.

Learn more about our editorial process.

Appointments 800.659.7822