Chronic Coronary Total Occlusion

The heart is a muscle, and — like any other muscle — it needs oxygen-rich blood.

Chronic coronary total occlusion (CTO) occurs when a buildup of plaque blocks the coronary artery for more than 90 days, starving your heart of oxygen. Left untreated, CTO can cause chest pain, unusual fatigue, and lifestyle restrictions.

The UPMC Heart and Vascular Institute is one of a few centers with the expertise in performing angioplasty to treat CTO.

Contact the UPMC Heart and Vascular Institute

To request an appointment, contact the UPMC Heart and Vascular Institute:

What Is Chronic Coronary Total Occlusion?

Chronic coronary total occlusion (CTO) occurs when either the left main or right coronary artery — one of the arteries that delivers oxygen-rich blood to your heart — has become completely blocked or occluded for three months or longer.

Approximately 15 to 20 percent of people with coronary artery disease have a CTO.

Without treatment, a CTO can lead to:

  • Chest pain (called angina)
  • Shortness of breath
  • Fatigue
  • Inability to participate in many normal daily activities

Causes and complications of chronic coronary total occlusion

Atherosclerosis, also known as hardening of the arteries, causes CTO.

Healthy arteries are flexible and smooth and allow blood to flow freely through them.

In atherosclerosis, fatty deposits and calcium can build up along the inner artery walls and form plaque. Over time, the buildup of plaque causes the arteries to narrow. This limits the amount of oxygen-rich blood that flows to the heart.

With CTO, the artery blockage is usually gradual. Because it happens over time, the body often adapts by creating small blood vessels that circumvent the blockage. The “collaterals” (or detours) form a natural bypass of the blockage by connecting the area of the heart that gets enough blood flow to the end of the vessel that is chronically occluded.

This re-routed blood flow helps deliver blood to the heart — partly making up for the blocked artery and usually protecting a person against a heart attack. However, this collateral circulation often does not supply enough blood to meet increased demand during exercise.

When a person with CTO increases his or her level of exertion, the result can be shortness of breath or chest pain.

Chronic coronary total occlusion risk factors

People who have had a previous heart attack or bypass surgery are more likely to develop CTO.

Like other forms of heart disease, you can control some risk factors but not others.

Factors you cannot control include:

  • Family history, such as if your parents or siblings had heart disease
  • Age (45 years for men, 55 for women)

Risk factors for heart disease you can control include:

  • Tobacco use
  • Being overweight or obese
  • High blood pressure
  • High cholesterol
  • Eating a diet high in fat and cholesterol
  • Not exercising
  • Diabetes
  • Excessive alcohol use

Why choose UPMC for CTO treatment?

Historically, angioplasty and stenting was not an effective treatment for CTO. People either had bypass surgery or received medication to treat their CTO.

In recent years, angioplasty equipment and techniques have improved greatly, and it is becoming an option for many people with CTO. In fact, the UPMC Heart and Vascular Institute is the only center in western Pennsylvania that offers a program dedicated to angioplasty treatment for CTO.

Our interventional cardiologists have developed the experience and skill necessary to perform this technically demanding procedure with very high success rates that are on par with other dedicated CTO centers nationally.

Learn More About Chronic Coronary Total Occlusion

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Chronic Coronary Total Occlusion Symptoms and Diagnosis

Chronic coronary total occlusion symptoms

During the early stages of chronic coronary total occlusion (CTO), there may be no symptoms at all.

When people do have CTO symptoms, they can include:

  • Chest pain, called angina
  • Shortness of breath
  • Fatigue

Diagnosing chronic coronary total occlusion

Your doctor at the UPMC Heart and Vascular Institute will use cardiac catheterization and angiography to diagnose CTO.

In cardiac catheterization and angiography, your doctor:

  • Inserts a catheter into a blood vessel in your leg or wrist.
  • Advances the catheter to your heart.
  • Injects a dye into the blood vessels of the heart. This dye is visible on x-rays, allowing the doctor to see blood flow through the heart and its arteries and identify CTO.

To make an appointment at the Heart and Vascular Institute, call 1-855-876-2484 (UPMC-HVI) or email

Learn More About Testing for CTO

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Chronic Coronary Total Occlusion Treatment

Chronic coronary total occlusion (CTO) treatment aims to restore blood flow through the blocked or occluded artery to the heart.

In the past, angioplasty and stenting was not very successful at treating CTO, and doctors would use bypass surgery to restore blood flow to the heart.

Angioplasty instruments and techniques have improved in recent years.

In addition to offering coronary artery bypass graft surgery (bypass surgery), the UPMC Heart and Vascular Institute offers angioplasty and stenting for CTO.

Angioplasty and stenting

In angioplasty, your interventional cardiologist will:

  • Insert a guide wire and advance it through your arteries to and across the blockage using fluoroscopy (a type of moving x-ray that allows the doctor to see the blood vessels on a monitor).
  • Advance a catheter sheath wire and insert a catheter through the catheter sheath. The catheter has a balloon at its tip.
  • Inflate and deflate the balloon until the blockage is flattened against the artery wall.

After angioplasty, your interventional cardiologist will place a stent. A stent expands against the artery walls and acts like a scaffold to make sure the artery stays open.

Bypass surgery for chronic coronary total occlusion

In bypass surgery — after making an incision in the chest to gain access to the heart and blood vessels — your UPMC surgeon attaches one end of a blood vessel taken from another part of your body (or from a cadaver) and attaches one end to the blocked artery above the blockage and the other end below the blockage.

Blood then bypasses the blockage and flows through the newly attached blood vessel. This restores blood flow to the heart.

Whether with bypass surgery or angioplasty and stenting, your UPMC doctor will work with you to develop a CTO treatment plan that’s right for your unique circumstances.

To make an appointment at the Heart and Vascular Institute, call 1-855-876-2484 or email

Learn More About Chronic Coronary Total Occlusion Treatments

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From our Health Library

Chronic Coronary Total Occlusion Education Materials

The UPMC Heart and Vascular Institute offers educational information and videos about chronic coronary total occlusion and other heart and vascular conditions.

Many people find these resources helpful in preparing for a procedure or diagnostic test and answering their questions about their condition.

The links below will open a new browser window.

UPMC Heart and Vascular Institute

From our Health Library