Chronic total occlusion is a chronic (lasting three or more months) 100% blockage of the heart arteries. Your coronary arteries are the blood vessels that carry blood to your heart. A CTO restricts blood flow to your heart, which can cause chest pain, shortness of breath or a heart attack.
What is chronic total occlusion?
Coronary artery disease (CAD) is the leading cause of death in the world and the most common type of heart disease. It occurs when plaque builds up in the coronary arteries and reduces the amount of blood reaching the heart. However, it is important to know that there are differences in how a coronary artery can become blocked.
When a coronary artery is not just narrowed but completely blocked, it is called a total occlusion. If this complete blockage lasts for 3 months or longer, it is called a chronic total occlusion, or CTO for short.
People with CTO may experience chest pain, shortness of breath, and fatigue, and they are also at higher risk for heart attack and other serious heart problems.
CTO is a common condition. It can occur in up to one in five people who have a coronary angiogram, an imaging test used to evaluate blood flow in the arteries. Fortunately, there are treatments available that can help reduce chest pain and discomfort, as well as other symptoms.
Treatment for CTO can be more complicated than a standard coronary angioplasty. Since the artery is completely closed, two catheters are usually placed during the treatment process, one to clarify the path ahead of the artery and the other to show the collateral (alternating) flow from other vessels to the affected area. Using special techniques, these two areas are reconnected, usually with the placement of stents. Sometimes more than one procedure is required to achieve an optimum result.
Who is at risk for chronic total occlusion?
Chronic total occlusions are more common in people with coronary artery disease (CAD). About 1 in 3 people with CAD also have CTO. The risk factors for CTO are very similar to those for CAD. You’re more likely to develop CTO if you smoke or have other risk factors, such as:
- Body mass index (BMI) of 30 or higher
- Diabetes
- Family history of heart disease
- Hypertension
- High cholesterol (hyperlipidemia)
- History of heart attack or coronary artery bypass surgery
- Inactive lifestyle
The likelihood of CTO increases as people get older. CTOs:
- Affect about 37% of people under the age of 65,
- Affect about 40% of people between the ages of 65 and 79,
- Affect about 41% of people over the age of 85.
The true prevalence of CTOs may be higher than experts estimate. Some chronic total occlusions do not cause symptoms, so people can have the condition without a formal diagnosis.
What are the symptoms of chronic total occlusion?
CTO symptoms may include:
- Chest pain, tightness, or pressure
- Dizziness
- Fatigue
- Irregular heartbeat
- Nausea
- Rapid heartbeat
- Shortness of breath
- Upper arm pain
CTO symptoms usually get worse when you exert yourself and get better with rest. However, you may also experience symptoms while you are resting. You may also have no symptoms at all.
How is chronic total occlusion diagnosed?
A definitive diagnosis of CTO is documented with a coronary angiogram. In this test, your doctor inserts a catheter (a thin, flexible tube) into an artery in your wrist or groin and then guides it through a blood vessel to your heart. A contrast fluid is injected through the catheter into blood vessels near your heart, and then X-ray images are taken. The contrast fluid allows doctors to see how blood flows through your coronary arteries and identify blockages.
CTO is diagnosed when a coronary artery is completely blocked. In some cases, CTO is diagnosed in patients who are undergoing a coronary angiogram for another cardiovascular condition. Your doctor may order additional tests to evaluate how well your heart and coronary arteries are working. These may include an echocardiogram (ultrasound of the heart), a stress test, or an MRI to evaluate your heart’s function and the likelihood of a successful procedure. A stress test consists of an electrocardiogram (ECG) of your heart being stressed, usually with exercise such as walking on a treadmill or riding a stationary bike.
How is chronic total occlusion treated?
A CTO treatment plan typically focuses on reducing symptoms and risks, such as heart attack. The treatment you need depends on how severe your symptoms are and whether you’re already receiving treatment for CAD. Your doctor may recommend:
Drug Therapy: A number of medications can be used to help your heart work better, slow or stop plaque buildup in your arteries, and reduce symptoms. These medications may include antiplatelet drugs, beta-blockers, ACE inhibitors, angiotensin receptor blockers (ARBs), calcium channel blockers, statins or nitrates, and others. If symptoms persist, additional interventions may be needed.
Percutaneous coronary intervention (PCI): Also known as coronary balloon and stent therapy, PCI places a small, hollow tube (catheter) into a blood vessel in your groin or wrist. A small balloon at the end of a catheter that is guided into your coronary artery is inflated, and a stent is placed inside the artery to restore blood flow. PCI improves blood flow, which reduces heart-related chest pain (angina), helps you feel better, and keeps you alert.
After a percutaneous coronary intervention, your coronary artery may narrow or block again. In these cases, your symptoms usually return and you may need another PCI or coronary bypass surgery.
Coronary artery bypass graft (CABG): A bypass is also known as coronary artery bypass and heart bypass surgery. During CABG, a healthy artery or vein is taken from another part of the body (usually the chest, leg, or arm) and attached (grafted) to the blocked coronary artery. The grafted artery or vein bypasses (bypasses) the blocked part of the coronary artery, allowing the new channel to direct oxygen-rich blood to the heart muscle.
There are several different types of CABG. Coronary artery bypass grafting procedures range from traditional methods to less invasive surgeries to a robot-assisted technique that allows the surgeon to perform the operation with remote-controlled surgical instruments.
What is the goal of treatments applied in chronic total occlusion?
The goal of CTO treatment has several components:
- Improve and resolve lifestyle-limiting symptoms (such as pain)
- Maintain a lasting outcome
- Ensure that certain CAD risk factors are well controlled to minimize the risk of future CAD-related problems
In addition to treatment, it is important for people with CTO to make heart-healthy lifestyle changes, such as quitting smoking, exercising, controlling blood pressure and cholesterol levels, and maintaining a healthy weight—even after treatment.
Sources:
- Yale
- National Institutes of Health (NIH)
- AHA Journals
- Penn Medicine