What is coronary artery disease?
Coronary artery disease occurs when fatty deposits called plaque (say "plak") build up inside the coronary arteries. The coronary arteries wrap around the heart and supply it with blood and oxygen. When plaque builds up, it narrows the arteries and reduces the amount of blood that gets to your heart. This can lead to serious problems, including heart attack.
Coronary artery disease (also called CAD) is the most common type of heart disease. It is also the number one killer of both men and women in the United States.
It can be a shock to find out that you have coronary artery disease. Many people only find out when they have a heart attack. Whether or not you have had a heart attack, there are many things you can do to slow coronary artery disease and reduce your risk of future problems.
What causes coronary artery disease?
Coronary artery disease is caused by hardening of the arteries, or atherosclerosis. Atherosclerosis occurs when plaque builds up inside the arteries. (Arteries are the blood vessels that carry oxygen-rich blood throughout your body.) Atherosclerosis can affect any arteries in the body. When it occurs in the arteries that supply blood to the heart, it is called coronary artery disease.
Plaque is a fatty material made up of cholesterol, calcium, and other substances in the blood. To understand why plaque is a problem, compare a healthy artery with an artery with atherosclerosis:
- A healthy artery is like a rubber tube. It is smooth and flexible, and blood flows through it freely. If your heart has to work harder, such as when you exercise, a healthy artery can stretch to let more blood flow to your body’s tissues.
- An artery with atherosclerosis is more like a clogged pipe. Plaque narrows the artery and makes it stiff. This limits the flow of blood to the tissues. When the heart has to work harder, the stiff arteries can't flex to let more blood through, and the tissues don't get enough blood and oxygen.
See a picture of a normal artery and an artery narrowed by plaque.
When plaque builds up in the coronary arteries, the heart doesn't get the blood it needs to work well. Over time, this can weaken or damage the heart. If a plaque tears, the body tries to fix the tear by forming a blood clot around it. The clot can block blood flow to the heart and cause a heart attack. See a picture of how plaque causes a heart attack.
What are the symptoms?
Usually people with coronary artery disease don't have symptoms until after age 50. Then they may start to have symptoms at times when the heart is working harder and needs more oxygen, such as during exercise. Typical first symptoms include:
- Chest pain, called angina (say “ANN-juh-nuh” or “ann-JY-nuh”).
- Shortness of breath.
- Heart attack. Too often, a heart attack is the first symptom of coronary artery disease.
Less common symptoms include a fast heartbeat, feeling sick to your stomach, and increased sweating. Some people don't have any symptoms. In rare cases, a person can have a “silent” heart attack, without symptoms.
To find out your risk for a heart attack in the next 10 years, use this Interactive Tool: Are You at Risk for a Heart Attack?
How is coronary artery disease diagnosed?
To diagnose coronary artery disease, doctors start by doing a physical exam and asking questions about your past health and your risk factors. Risk factors are things that increase the chance that you will have coronary artery disease.
Some common risk factors are being older than 65; smoking; having high cholesterol, high blood pressure, or diabetes; and having heart disease in your family. The more risk factors you have, the more likely it is that you have coronary artery disease.
If your doctor thinks that you have coronary artery disease, you may have tests, such as:
- Electrocardiogram (EKG or ECG), which checks for problems with the electrical activity of your heart. An EKG can also show signs of an old or new heart attack.
- Chest X-ray.
- Blood tests.
- Exercise electrocardiogram, commonly called a "stress test." This test checks for changes in your heart while you exercise.
Your doctor may order other tests to look at blood flow to your heart. You may have a coronary angiogram if your doctor is considering a procedure to remove blockages, such as angioplasty or bypass surgery.
How is it treated?
Treatment focuses on taking steps to manage your symptoms and reduce your risk for heart attack and stroke. Some risk factors you can't control, such as your age and family history. Other risk factors you can control, such as high blood pressure, high cholesterol, and smoking. Lifestyle changes can help lower your risks. You may also need to take medicines or have a procedure to open your arteries.
Lifestyle changes are the first step for anyone with coronary artery disease. These changes may stop or even reverse coronary artery disease. To improve your heart health:
- Don't smoke. This may be the most important thing you can do. Quitting smoking can quickly reduce the risk of heart attack or death.
- Eat a heart-healthy diet that includes plenty of fish, fruits, vegetables, beans, high-fiber grains and breads, and olive oil. See a dietitian if you need help making better food choices.
- Get regular exercise on most, if not all, days of the week. Your doctor can suggest a safe level of exercise for you. Walking is great exercise that most people can do. A good goal is 30 minutes or more a day.
- Lower your stress level. Stress can hurt your heart.
Changing old habits may not be easy, but it is very important to help you live a healthier and longer life. Having a plan can help. Start with small steps. For example, commit to eating five servings of fruits and vegetables a day. Instead of having dessert, take a short walk. When you feel stressed, stop and take some deep breaths.
Medicines may be needed in addition to lifestyle changes. Medicines that are often prescribed for people with coronary artery disease include:
- Statins to help lower cholesterol.
- Beta-blockers or ACE inhibitors to lower blood pressure.
- Aspirin or other medicines to reduce the risk of blood clots.
- Nitrates to relieve chest pain.
Procedures may be done to improve blood flow to the heart.
- Angioplasty is used to open blocked arteries. It isn't major surgery. During angioplasty, the doctor guides a thin tube (called a catheter) into the narrowed artery and inflates a small balloon. This widens the artery to help restore blood flow. Often a small wire-mesh tube called a stent is placed to keep the artery open. See a picture of angioplasty with stent placement. The doctor may use a stent that is coated with medicine, called a drug-eluting stent. When the stent is in place, it slowly releases a medicine that prevents the growth of new tissue. This helps keep the artery open.
- Bypass surgery, which is major surgery, may be used if more than one coronary artery is blocked. It uses healthy blood vessels to create detours around narrowed or blocked arteries.
What else can you do?
To stay as healthy as possible, it is important to:
- See your doctor for regular follow-up appointments. This lets your doctor keep track of your risk factors and adjust your treatment as needed.
- Take your medicines exactly as prescribed. Do not stop or change medicines without talking to your doctor.
- Keep nitroglycerin with you at all times, if your doctor prescribed it for chest pain.
- Tell your doctor about any chest pain you have had, even if it went away.
- Get the support you need to succeed in making lifestyle changes. Ask family or friends to share a healthy meal or join a stop-smoking program with you. Or ask your doctor about a cardiac rehab program. In cardiac rehab, a team of health professionals provides education and support to help you make new, healthy habits.