Coronary artery occlusion is a partial or total blockage of one of the arteries in your heart. It can cause shortness of breath and chest pain but sometimes doesn’t cause symptoms until you experience a complication, like a heart attack.

Your coronary arteries supply your heart with blood. Coronary artery occlusion is a partial or complete blockage of one of your coronary arteries, which can lead to a heart attack.

The underlying cause of coronary artery occlusion is usually coronary artery disease (CAD). CAD results from plaque buildup inside your coronary arteries, causing them to narrow. Pieces of this plaque can break off and lead to a blood clot and blockage inside your heart.

Read on to learn more about coronary artery occlusion, including symptoms, causes, and potential complications.

Partial vs. total coronary occlusion

A blockage in your coronary artery can be:

  • a total or complete coronary occlusion if no or very little blood can pass through
  • a partial occlusion or stenosis (narrowing) if some blood can still pass through

Medical professionals define chronic total occlusion of the coronary artery as a complete blockage of the coronary artery for more than 3 months.

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Coronary artery occlusion can prevent your heart tissue from receiving enough blood and oxygen. People with a partial blockage may only have symptoms with exercise, whereas people with total occlusion may always have symptoms such as:

Symptoms of a heart attack

Coronary artery occlusion can lead to a heart attack. According to the Centers for Disease Control and Prevention (CDC), the major symptoms of a heart attack are:

  • pain in the center or left side of your chest that lasts for more than several minutes or goes away and comes back
  • feeling faint, light-headed, or weak
  • pain in your:
    • jaw
    • neck
    • back
  • pain in one or both of your arms or shoulders
  • shortness of breath

Learn more about the early indications of a heart attack.

Coronary artery occlusion is usually a complication of CAD. Plaque inside your blood vessels, often developing over many years, leads to CAD by narrowing your coronary arteries and reducing blood flow.

Plaque can also break off your coronary arteries and lead to a blood clot that completely obstructs one of your coronary arteries.

Another cause of coronary artery occlusion is a coronary artery spasm, which is a temporary constriction (tightening) of the muscles inside your coronary arteries.

The risk factors of coronary artery occlusion are similar to those of CAD. These risk factors include:

The leading risk factor for coronary arterial spasms is smoking.

Doctors can typically make a diagnosis with a test called a coronary angiogram. During this test, your doctor injects a dye into your blood vessels, allowing blood flow to show up on an X-ray.

Doctors can grade the amount of blood flowing through your coronary artery on the following scale:

Thrombolysis in myocardial infarction (TIMI) Grading systemDescription
TIMI 0a small amount of blood flow through the occlusion
TIMI 1a small amount of blood flow through the occlusion
TIMI 2minor disruptions in blood flow
TIMI 3regular blood flow

Another diagnostic tool is coronary computed tomography angiography (CCTA). It’s a CT scan that looks specifically at your coronary arteries and can estimate the percentage of plaque buildup.

Other tests you might receive include:

Treatment for total coronary artery occlusion usually includes one of the following:

  • Percutaneous coronary intervention (PCI): During a PCI, a surgeon inserts a balloon into one of your arteries, moving it through your bloodstream with a long wire until it reaches your heart. The surgeon then expands the balloon in your coronary artery to relieve the blockage before inserting a stent to keep the artery open.
  • Coronary artery bypass graft: A coronary bypass involves taking a blood vessel from another part of your body and using it to create a new pathway for blood to flow around the blockage.

Doctors can often treat partial artery occlusion similarly to stable angina. They can prescribe beta-blockers to treat chest pain. Calcium channel blockers and long-acting nitrates are alternative treatment options.

A doctor will usually recommend lifestyle and dietary changes in combination with these treatments.

Coronary artery occlusion can lead to a heart attack if your heart doesn’t receive an adequate supply of blood. A heart attack can lead to permanent scarring of your heart or death.

Your outlook with coronary artery occlusion depends on the severity of the blockage. Total occlusion is associated with a worse outlook and higher death rates.

In a small 2022 study, researchers examined the outcomes of people with chronic total coronary artery occlusion who received medications or PCI at an average follow-up of 56 months. They observed the following:

  • Six of the 48 people who received medications died of cardiovascular disease, and 11 died in total.
  • Three of the 44 people who received PCI died of cardiovascular disease, and 4 died in total.
  • There was no difference in rates of cardiovascular events or quality of life between the groups.

Ways you can prevent CAD and coronary artery occlusion include:

Learn more about how to reduce your risk of heart disease.

Here are some frequently asked questions people have about coronary occlusion.

What is the survival rate for right coronary artery blockage?

In a 2021 study, researchers looked at the 10-year mortality rate for people who had received either PCI or a coronary bypass to treat a total occlusion. They found it ranged from 21.4–29.9%, depending on which treatment people received and whether they had a complete occlusion.

What are the warning signs of clogged arteries?

Experts often consider CAD to be a silent disease because it may not cause symptoms until a significant blockage causes a heart attack. A type of chest pain called angina is often one of the first symptoms to appear.

Is a coronary occlusion a heart attack?

Coronary occlusion is a partial or complete blockage of a coronary artery. This blockage can lead to a heart attack if your heart tissue can’t receive enough blood.

Coronary occlusion is a total or partial blockage of one of the arteries that supply your heart with blood. It can lead to the death of heart tissue and a heart attack.

Doctors often treat a total coronary occlusion with a coronary bypass or PCI. Partial occlusions may be treatable with medications and lifestyle changes.