Coronary artery disease

Overview

Coronary artery disease (CAD) is a common type of heart disease. It affects the main blood vessels that supply blood to the heart, called the coronary arteries. In CAD, there is reduced blood flow to the heart muscle. A buildup of fats, cholesterol and other substances in and on the artery walls, a condition called atherosclerosis, usually causes coronary artery disease. The buildup, called plaque, makes the arteries narrow.

Coronary artery disease often develops over many years. Symptoms are from the lack of blood flow to the heart. They may include chest pain and shortness of breath. A complete blockage of blood flow can cause a heart attack.

Treatment for coronary artery disease may include medicines and surgery. Eating a nutritious diet, getting regular exercise and not smoking can help prevent coronary artery disease and the conditions that can cause it.

Coronary artery disease also may be called coronary heart disease.

Symptoms

Symptoms of coronary artery disease happen when the heart doesn't get enough oxygen-rich blood. Coronary artery disease symptoms may include:

• Chest pain, called angina. You may feel squeezing, pressure, heaviness, tightness or pain in the chest. It may feel like somebody is standing on your chest. The chest pain usually affects the middle or left side of the chest. Activity or strong emotions can trigger angina. There are different types of angina. The type depends on the cause and whether rest or medicine makes symptoms better. In some people, especially women, the pain may be brief or sharp and felt in the neck, arm or back.
• Shortness of breath. You may feel like you can't catch your breath.
• Fatigue. If the heart can't pump enough blood to meet your body's needs, you may feel unusually tired.

Symptoms of coronary artery disease may not be noticed at first. Sometimes symptoms only happen when the heart is beating hard, such as during exercise. As the coronary arteries continue to narrow, symptoms can get more severe or frequent.

A completely blocked coronary artery will cause a heart attack. Common heart attack symptoms include:

• Chest pain that may feel like pressure, tightness, squeezing or aching.
• Pain or discomfort that spreads to the shoulder, arm, back, neck, jaw, teeth or sometimes the upper belly.
• Cold sweats.
• Fatigue.
• Heartburn.
• Nausea.
• Shortness of breath.
• Lightheadedness or sudden dizziness.

Chest pain is usually the most common symptom of heart attack. But for some people, such as women, the elderly and those with diabetes, symptoms may seem unrelated to a heart attack. For example, they may have nausea or a very brief pain in the neck or back. Some people having a heart attack don't notice symptoms.

When to see a doctor

If you think you're having a heart attack, immediately call 911 or your local emergency number. If you don't have access to emergency medical services, have someone drive you to the nearest hospital. Drive yourself only as a last option.

Smoking or having high blood pressure, high cholesterol, diabetes, obesity or a strong family history of heart disease makes you more likely to get coronary artery disease. If you're at high risk of coronary artery disease, talk to your healthcare professional. You may need tests to check for narrowed arteries and coronary artery disease.

Causes

Coronary artery disease is caused by the buildup of fats, cholesterol and other substances in and on the walls of the heart arteries. This condition is called atherosclerosis. The buildup is called plaque. Plaque can cause the arteries to narrow, blocking blood flow. The plaque also can burst, causing a blood clot.

Some causes of atherosclerosis and coronary artery disease are:

• Diabetes or insulin resistance.
• High blood pressure.
• Lack of exercise.
• Smoking or tobacco use.

Risk factors

Coronary artery disease is common.

Coronary artery disease risk factors you can't control include:

• Age. Getting older increases the risk of damaged and narrowed arteries.
• Birth sex. Men are generally at greater risk of coronary artery disease. However, the risk for women increases after menopause.
• Family history. A family history of heart disease makes you more likely to get coronary artery disease. This is especially true if a parent, brother, sister or child got heart disease at an early age. The risk is highest if your father or a brother had heart disease before age 55 or if your mother or a sister developed it before age 65.

Coronary artery disease risk factors you can control are:

• Smoking. If you smoke, quit. Smoking is bad for heart health. People who smoke have a much greater risk of heart disease. Breathing in secondhand smoke also increases the risk.
• High blood pressure. Uncontrolled high blood pressure can make arteries hard and stiff. This can lead to atherosclerosis, which causes coronary artery disease.
• Cholesterol. Too much "bad" cholesterol in the blood can increase the risk of atherosclerosis. "Bad" cholesterol is called low-density lipoprotein (LDL) cholesterol. Not enough "good" cholesterol, called high-density lipoprotein (HDL) cholesterol, also leads to atherosclerosis.
• Diabetes. Diabetes increases the risk of coronary artery disease. Type 2 diabetes and coronary artery disease share some risk factors, such as obesity and high blood pressure.
• Obesity. Too much body fat is bad for overall health. Obesity can lead to type 2 diabetes and high blood pressure. Ask your healthcare team what a healthy weight is for you.
• Chronic kidney disease. Having long-term kidney disease increases the risk of coronary artery disease.
• Not getting enough exercise. Physical activity is important for good health. A lack of exercise is linked to coronary artery disease and some of its risk factors.
• A lot of stress. Emotional stress may damage the arteries and worsen other risk factors for coronary artery disease.
• Unhealthy diet. Eating foods with a lot of saturated fat, trans fat, salt and sugar can increase the risk of coronary artery disease.
• Alcohol use. Heavy alcohol use can lead to heart muscle damage. It also can worsen other risk factors of coronary artery disease.
• Amount of sleep. Too little sleep and too much sleep both have been linked to an increased risk of heart disease.

Risk factors often happen together. One risk factor may trigger another. When grouped together, some risk factors make you even more likely to develop coronary artery disease. For example, metabolic syndrome is a group of conditions that includes high blood pressure, high blood sugar, too much body fat around the waist and high triglyceride levels. Metabolic syndrome increases the risk of coronary artery disease.

Other possible risk factors for coronary artery disease may include:

• Breathing pauses during sleep, called obstructive sleep apnea. This condition causes breathing to stop and start during sleep. It can cause sudden drops in blood oxygen levels. The heart must work harder to pump blood. Blood pressure goes up.
• Increased high-sensitivity C-reactive protein (hs-CRP). This protein appears in higher than usual amounts when there's inflammation somewhere in the body. High hs-CRP levels may be a risk factor for heart disease. It's thought that as coronary arteries narrow, the level of hs-CRP in the blood goes up.
• High triglycerides. This is a type of fat in the blood. High levels may raise the risk of coronary artery disease, especially for women.
• High levels of homocysteine. Homocysteine is a substance that the body uses to make protein and to build and maintain tissue. But high levels of homocysteine may raise the risk of coronary artery disease.
• Preeclampsia. This pregnancy complication causes high blood pressure and increased protein in the urine. It can lead to a higher risk of heart disease later in life.
• Other pregnancy complications. Diabetes or high blood pressure during pregnancy are known risk factors for coronary artery disease.
• Certain autoimmune diseases. People who have conditions such as rheumatoid arthritis and lupus have an increased risk of atherosclerosis.

Complications

Complications of coronary artery disease may include:

• Chest pain, also called angina. This is a symptom of coronary artery disease. But it also can be a complication of worsening CAD. The chest pain happens when arteries narrow and the heart doesn't get enough blood.
• Heart attack. A heart attack can happen if atherosclerosis causes a blood clot. A clot can block blood flow. The lack of blood can damage the heart muscle. The amount of damage depends in part on how quickly you are treated.
• Heart failure.Narrowed arteries in the heart or high blood pressure can slowly make the heart weak or stiff. This can make it harder for the heart to pump blood.
• Irregular heart rhythms, called arrhythmias. If the heart doesn't get enough blood, changes in heart signaling can happen. This can cause irregular heartbeats.