What is chronic total occlusion (CTO)?
A chronic total occlusion (CTO) is a complete or near-complete blockage in one or more coronary arteries that lasts three months or longer. The coronary arteries are the blood vessels that supply blood to the heart.
A CTO commonly develops in people with coronary artery disease. Other names for a chronic total occlusion include coronary occlusion and coronary artery occlusion.
What is a functional CTO?
Cardiologists often use the term “functional CTO” to describe a coronary artery that is severely but not completely blocked. They may use the term “true CTO” to describe a coronary artery that is completely blocked.
Your treatment plan may vary depending on whether you have a functional CTO or a true CTO. The more blocked or damaged your artery is, the more likely you’ll need a procedure to restore blood flow.
Chronic total occlusion symptoms
People with a CTO often experience more intense symptoms when they exert themselves and fewer symptoms when they’re at rest. CTO symptoms may include:
- Chest pain (angina), pressure or tightness
- Dizziness
- Fatigue
- Heart palpitations, or sensations of your heart pounding
- Irregular heart rhythms (arrhythmia)
- Shortness of breath
If you experience any of these symptoms, contact your doctor right away. Timely diagnosis and treatment can improve blood flow to your heart and reduce your risk of complications.
Causes of chronic total occlusion
A chronic total occlusion usually develops when a fatty substance called plaque builds up in the coronary arteries. The plaque hardens and narrows the coronary arteries.
You’re more likely to develop a CTO if you have risk factors such as:
- Diabetes
- Family history of heart disease
- Health history of coronary artery disease or heart attacks
- High blood pressure (hypertension)
- High cholesterol
Some lifestyle habits also increase your risk of a CTO, including:
- Eating a diet high in sodium
- Inactive lifestyle
- Smoking
CTO complications
Without treatment, a CTO can increase your risk of a heart attack, a sudden blockage in blood flow to your heart. Your doctor may prescribe medications or recommend procedures designed to open the blockage, relieve symptoms and reduce your risk of a heart attack.
Call 911 and seek emergency medical care right away if you experience any symptoms of a heart attack, such as:
- Chest pain
- Extreme fatigue
- Jaw, arm, neck or back pain
- Lightheadedness
- Nausea
- Shortness of breath.
The sooner you receive treatment, the less damage your heart muscle sustains.
Diagnosing a chronic total occlusion
We use several tests to diagnose a chronic total occlusion, including:
- Coronary angiography, using X-rays and contrast dye to view how blood flows through the coronary arteries
- Coronary artery calcium scan, using a CT scan to assess the coronary arteries for calcium or plaque buildup
- Echocardiogram to view the heart’s structures
- Electrocardiogram (EKG) to measure the electrical activity in the heart
- Electron-beam computed tomography (EBCT), using an electron gun to scan the chest and check for calcium buildup in the linings of the coronary arteries
- Exercise stress test to evaluate how the heart functions during exercise or while taking medications that mimic the effects of exercise
- Heart CT scan, using X-rays and specialized computers to create pictures of the heart
- Intravascular ultrasound to see inside the coronary artery walls, pinpoint plaque and plan treatment
- Nuclear stress test, injecting a small, safe amount of radioactive material into the bloodstream to see how well blood flows through the heart at rest and during exercise
Chronic total occlusion treatments at Penn Medicine
Chronic Total Occlusion (CTO) at Penn Medicine is one of the only in the region. Our subspecialized CTO experts provide exceptional care while continually researching new treatment options.
Our team provides targeted, advanced CTO treatment, including:
- Percutaneous coronary intervention (PCI): an interventional cardiologist inserts a small, flexible tube (catheter) through a blood vessel in the groin and guides it to the blocked artery. They inflate a balloon inside the artery to push plaque out of the way. Then they place a small mesh tube (stent) in the artery to keep it open.
- Complex bifurcation stenting: a complex bifurcation blockage occurs when a CTO develops at or near one of the smaller branches of the coronary artery. We use advanced PCI techniques to place a stent in the main blocked coronary artery as well as the smaller coronary artery branch.
- Left main coronary stenting: if the left main coronary artery is blocked, we can use PCI techniques to place a metal stent in the artery. The stent is coated with medication that releases into the artery and opens the blockage.
- Intravascular lithotripsy (IVL): we insert a specialized IVL catheter with a balloon through your blood vessel and guide it to the coronary artery. An electrical charge travels through the catheter and vaporizes fluid inside the balloon. This process generates sonic pressure waves that help break up calcium in the coronary artery.
- Coronary artery bypass graft (CABG): we use a blood vessel from elsewhere in your body to create a new path for blood to flow around the blocked coronary artery. A cardiac surgeon performs a CABG through open-chest surgery.