A stent thrombosis is a blood clot that forms within a coronary stent. It can be a complication of stent placement to open a narrowed artery.

A coronary stent is a mesh tube that opens a narrowed or blocked artery to restore blood flow to the heart.

A stent thrombosis is a severe complication of stent placement that can occur with percutaneous coronary intervention (PCI).

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A stent thrombosis typically develops rapidly and leads to acute coronary syndrome. Acute coronary syndrome is a sudden blockage of blood flow to the heart that may cause the following symptoms:

  • chest pain or discomfort
  • pain or discomfort in the arms, back, stomach, neck, or jaw
  • shortness of breath
  • feeling lightheaded or dizzy
  • nausea
  • sweating

If people experience these symptoms, call 911 immediately.

A stent thrombosis may occur due to a range of factors relating to the stent and a person’s biology. These factors may affect blood flow and the risk of a blood clot forming.

Delayed healing, which may occur with a drug-eluting stent, may also play a role in stent thrombosis. A drug-eluting stent is coated with medication that prevents tissue from growing and continued narrowing of the artery.

There is a risk of stent thrombosis if people do not take their antiplatelet or anticoagulant medication following stent placement. However, it is also possible for stent thrombosis to occur when people take their medication as a doctor advises.

Experts recommend continuing dual antiplatelet therapy (DAPT) for 1 year after the placement of a drug-eluting stent and at least 1 month after a bare-metal stent placement.

One of the main risk factors for stent thrombosis is not taking antiplatelet medication as a doctor prescribes following stent placement.

Other risk factors for stent thrombosis include:

  • diabetes
  • kidney impairment
  • acute coronary syndrome
  • reduced left ventricular ejection fraction, which is a problem with how the heart muscle contracts
  • non-ST elevation myocardial infarction (NSTEMI) and ST-elevation myocardial infarction (STEMI), which are both types of heart attack
  • the extent of coronary artery disease
  • the size and positioning of the stent

There is no significant association between the type of stent and the risk of stent thrombosis, though the type of stent may affect the timing of stent thrombosis.

Experts associate an earlier occurrence of stent thrombosis around 30 days post-procedure with bare-metal stents. They associate drug-eluting stents with stent thrombosis at 3 months or later post-procedure.

To diagnose stent thrombosis, a doctor will take a medical history and conduct a physical examination to assess any symptoms. They may carry out tests to check the heart, such as:

Doctors may use intravascular ultrasound (IVUS) or optical coherence tomography (OCT) to examine the stent and identify what is causing the stent thrombosis.

IVUS uses a catheter with an ultrasound to create an image within the blood vessels to check for any narrowing or blockages.

OCT also creates images within the blood vessels, but it uses light rather than sound waves to create the images.

Doctors may use aspiration thrombectomy or angioplasty to treat stent thrombosis.

Aspiration thrombectomy is a surgical procedure that uses a catheter and a device to suction and remove a blood clot from a stent.

In angioplasty, a doctor guides a catheter through the blood vessels to the blockage and inflates a small balloon to open the narrowed passage.

Doctors may place an additional stent to prevent the recurrence of a stent thrombosis.

Doctors may prescribe more powerful antiplatelet treatment, such as ticagrelor (Brilinta) or prasugrel (Effient), to reduce the risk of stent thrombosis recurring.

Without treatment, stent thrombosis may lead to severe complications, including heart attack, cardiogenic shock, or death.

Treatments for stent thrombosis also have a risk of complications similar to those with PCI, including:

  • bruising
  • hematoma, which is the leaking of blood from a blood vessel
  • pseudoaneurysm, which is a pooling of blood due to an injured artery
  • retroperitoneal hemorrhage, bleeding into the retroperitoneal space, which is behind the lining of the abdomen
  • arrhythmia or irregular heartbeat
  • impaired kidney function
  • recurrence of a blood clot
  • infection
  • ischemic stroke
  • heart attack

Taking DAPT exactly as a doctor prescribes may help prevent stent thrombosis. According to a 2021 article, using DAPT with PCI considerably decreases the occurrence of stent thrombosis.

There is a much higher risk of stent thrombosis if people stop taking antiplatelets earlier than a doctor advises. Stronger antiplatelet treatments, such as prasugrel, may reduce the risk of stent thrombosis by 50%.

Close monitoring within the first few months after stent placement is essential to check for any problems.

People will need to seek emergency medical attention if they have chest pain, shortness of breath, or any other symptoms of acute coronary syndrome following a stent placement.

Stent thrombosis is a rare but severe complication of coronary stent placement, with a mortality rate of up to 45%. Stent thrombosis may recur, with a recurrence rate of up to 20%.

Stent thrombosis may cause acute coronary syndrome and lead to heart attack or cardiac death. Early recognition and treatment of a stent thrombosis greatly improve the outlook.

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Stent thrombosis is a blood clot that forms in a coronary stent following percutaneous coronary intervention (PCI). A stent thrombosis can be life threatening without prompt treatment.

Treatment involves removing the blood clot and reopening the stent. Antiplatelet therapy may help reduce the risk of stent thrombosis.

If people experience any chest pain, shortness of breath, or other concerning symptoms following stent placement, they should seek medical help immediately.