A chronic total occlusion (CTO) is a blockage in your coronary arteries, the blood vessels that supply blood to your heart. The blockage is usually the result of a fatty substance called plaque building up and narrowing your arteries. You’re more likely to develop a CTO if you have coronary artery disease.
A chronic total occlusion (CTO) is a total blockage in one of your coronary arteries lasting three or more months. Your coronary arteries are the blood vessels that carry blood to your heart. CTOs restrict blood flow to your heart, which can lead to chest pain, shortness of breath or a heart attack.
Chronic total occlusions are more common in people who have coronary artery disease (CAD). Up to 1 in 3 people with CAD also have a CTO.
The risk factors for the development of a CTO are very similar for CAD. You are more likely to develop a CTO if you smoke or have other risk factors such as:
CTOs are more common as people get older. CTOs affect:
The actual prevalence of CTOs could be higher than experts estimate. Some CTOs don’t cause symptoms, so people may have a CTO without a formal diagnosis.
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CTO symptoms may include:
CTO symptoms often worsen when you exert yourself and lessen during rest. However, you may also experience symptoms while at rest. You may also have no symptoms at all.
Chronic total occlusions typically occur when a fatty substance called plaque builds up in one or more of your coronary arteries. This plaque buildup, called atherosclerosis, leads to artery narrowing and hardening. When atherosclerosis occurs in your coronary arteries, it’s called coronary artery disease.
Healthcare providers typically diagnose a chronic total occlusion using a coronary angiogram. During a coronary angiogram, your provider injects a contrast dye into your blood vessels. The dye highlights your blood vessels on an X-ray and shows how blood moves through your coronary arteries.
Your provider may also use tests such as a:
A CTO treatment plan typically focuses on lowering symptoms and reducing your risk of a heart-related event such as a heart attack. The treatment you need depends on how severe your symptoms are and whether you are already on a treatment plan for CAD. Your provider may recommend:
A chronic total occlusion is a serious condition, but treatment can help. Some research has shown that PCI successfully treats a CTO in up to 86% of patients. Other studies have shown that CABG successfully treats the condition in around 60% of patients.
If you have a chronic total occlusion or think you could, you may want to ask your healthcare provider:
A note from Cleveland Clinic
A chronic total occlusion is a complete blockage in one of your coronary arteries that has been present for three months or longer. A CTO restricts blood flow to your heart and can cause serious complications, including a heart attack. The goal of treatment is to manage symptoms. It often includes a percutaneous coronary intervention or a coronary artery bypass graft. Both options have high rates of successfully treating a CTO.
Last reviewed by a Cleveland Clinic medical professional on 08/03/2022.
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