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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.
What causes CTO?
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.
What are chronic coronary total occlusion risk factors and complications?
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.
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What Are The Signs And Symptoms Of CTO?
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.
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How Do You Diagnose CTO?
Your doctor 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.
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How Do You Treat CTO?
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.
Stenting
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.
Last reviewed by a UPMC medical professional on 2024-10-01.