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Coronary Heart Disease

November 17, 2021

Heart disease is a catch-all phrase for a variety of conditions that affect the heart’s structure and function. Coronary heart disease is a type of heart disease that develops when the arteries of the heart cannot deliver enough oxygen-rich blood to the heart. It is the leading cause of death in the United States.

Coronary heart disease is often caused by the buildup of plaque, a waxy substance, inside the lining of larger coronary arteries. This buildup can partially or totally block blood flow in the large arteries of the heart. Some types of this condition may be caused by disease or injury affecting how the arteries work in the heart. Coronary microvascular disease is another type of coronary heart disease. It occurs when the heart’s tiny blood vessels do not work normally.

Symptoms of coronary heart disease may be different from person to person even if they have the same type of coronary heart disease. However, because many people have no symptoms, they do not know they have coronary heart disease until they have chest pain, a heart attack, or sudden cardiac arrest.

If you have coronary heart disease, your doctor will recommend heart-healthy lifestyle changes, medicines, surgery, or a combination of these approaches to treat your condition and prevent complications.

Explore this Health Topic to learn more about coronary heart disease, our role in research and clinical trials to improve health, and where to find more information.

There are three main types of coronary heart disease: obstructive coronary artery disease, nonobstructive coronary artery disease, and coronary microvascular disease. Coronary artery disease affects the large arteries on the surface of the heart. Many people have both obstructive and nonobstructive forms of this disease. Coronary microvascular disease affects the tiny arteries in the heart muscle.

The cause depends on the type of coronary heart disease. The condition may also have more than one cause, including plaque buildup or problems that affect how the heart’s blood vessels work.

Plaque buildup in the arteries is called atherosclerosis.  When this buildup happens in the heart’s arteries over many years, the arteries become narrower and harden, reducing oxygen-rich blood flow to the heart. The result is coronary artery disease.

Normal vs a blocked artery
Normal versus a blocked artery. The image shows a normal coronary artery with normal blood flow and a blocked coronary artery narrowed by plaque. The buildup of plaque limits the flow of oxygen-rich blood through the artery. 

Obstructive coronary artery disease means the heart’s arteries are more than 50% blocked. The blood flow may eventually be completely blocked in one or more of the three large coronary arteries. In nonobstructive coronary artery disease, the large arteries may be narrowed by plaque, but not as much as they are in obstructive disease.

Small plaques can also develop in the small blood vessels in the heart, causing coronary microvascular disease.

Problems with how the heart’s blood vessels work can cause coronary heart disease. For example, the blood vessels may not respond to signals that the heart needs more oxygen-rich blood. Normally, the blood vessels widen to allow more blood flow when a person is physically active or under stress. But if you have coronary heart disease, the size of these blood vessels may not change, or the blood vessels may even narrow.

The cause of these problems is not fully clear. But it may involve:

  • Damage or injury to the walls of the arteries or tiny blood vessels from chronic inflammation, high blood pressure, or diabetes.
  • Molecular changes that are part of the normal aging process. Molecular changes affect the way genes and proteins are controlled inside cells.

In nonobstructive coronary artery disease, damage to the inner walls of the coronary arteries can cause them to spasm (suddenly tighten). This is called vasospasm. The spasm causes the arteries to narrow temporarily and blocks blood flow to the heart.

Spasm and plaque buildup causing arteries to narrow
Spasm and plaque buildup can cause your arteries to narrow. Top left: image of a heart showing the coronary arteries. Top right: This artery does not have plaque buildup but has a vasospasm, causing it to narrow. This is a type of nonobstructive coronary artery disease. Bottom left: This artery is also classified as nonobstructive because it is less than 50% blocked by plaque. However, the vasospasm causes severe narrowing. Bottom right: This artery also has a spasm but is considered to be obstructive coronary artery disease, because it is 80% blocked.  

These problems can also happen in the tiny blood vessels in the heart, causing coronary microvascular disease (sometimes called coronary syndrome X). Coronary microvascular disease can happen with or without obstructive or nonobstructive coronary artery disease.

Coronary microvascular disease in small arteries and obstructive coronary artery disease in large arteries
Coronary microvascular disease in small arteries and obstructive coronary artery disease in large arteries. Figure A shows the small coronary artery network, which includes a normal artery and an artery with coronary microvascular disease. Figure B shows a large coronary artery with plaque buildup.

Learn more about the important role that inflammation, which is the body’s reaction to an injury, plays in the development of coronary heart disease.

There are many risk factors for coronary heart disease. Your risk of coronary heart disease goes up with the number of risk factors you have and how serious they are. Some risk factors—such as high blood pressure and high blood cholesterol—can be changed through heart-healthy lifestyle changes. Other risk factors, such as sex, older age, family history and genetics, and race and ethnicity, cannot be changed.

Age
Environment and occupation

Your work life can also raise your risk if you:

  • Come into contact with toxins, radiation, or other hazards
  • Have a lot of stress at work
  • Sit for long periods
  • Work more than 55 hours a week, or work long, irregular, or night shifts that affect your sleep
Environment and occupation

Your work life can also raise your risk if you:

  • Come into contact with toxins, radiation, or other hazards
  • Have a lot of stress at work
  • Sit for long periods
  • Work more than 55 hours a week, or work long, irregular, or night shifts that affect your sleep
Lifestyle habits

Over time, unhealthy lifestyle habits increase your risk of coronary heart disease because they can lead to plaque buildup in the heart’s blood vessels. Unhealthy lifestyle habits that are risk factors include the following:

  • Being physically inactive, which can worsen other heart disease risk factors, such as high blood cholesterol and triglyceride levels, high blood pressure, diabetes and prediabetes, and overweight and obesity.
  • Not getting enough good quality sleep, including waking up often throughout the night, which may raise your risk of coronary heart disease. While you sleep, your blood pressure and heart rate fall. Your heart does not work as hard as it does when you are awake. As you begin to wake up, your blood pressure and heart rate increase to the usual levels when you are awake and relaxed. Waking up suddenly can cause a sharp increase in blood pressure and heart rate, which has been linked to angina and heart attacks. Learn more in our How Sleep Works topic.
  • Smoking tobacco or long-term exposure to secondhand smoke, which can damage the blood vessels.
  • Stress, which can trigger the tightening of your arteries, which increases your risk of coronary heart disease, especially coronary microvascular disease. Stress may also indirectly raise your risk of coronary heart disease if it makes you more likely to smoke or overeat foods high in fat and added sugars.
  • Unhealthy eating patterns, such as consuming high amounts of saturated fats or trans fats and refined carbohydrates (white bread, pasta, and white rice). This can lead to overweight and obesity, high blood cholesterol, atherosclerosis, and plaque buildup in the heart’s arteries.
Race or ethnicity

Coronary heart disease is the leading cause of death for people of most racial and ethnic groups in the United States, including African Americans, Hispanics, and whites.

For Asian Americans or Pacific Islanders and American Indians or Alaska Natives, heart disease is second only to cancer. People of South Asian ancestry are at higher risk of developing coronary heart disease and serious complications than other Asian Americans.

Sex

Coronary heart disease affects men and women. Obstructive coronary artery disease is more common in men. However, nonobstructive coronary artery disease is more common in women. Since the nonobstructive type is harder to diagnose, women may not be diagnosed and treated as quickly as men.

If you are a woman having chest discomfort or shortness of breath during physical activity, ask your doctor about tests to check for nonobstructive coronary artery disease or coronary microvascular disease.

Women may have a higher than normal risk for developing coronary heart disease if they have one of the following conditions.

  • Endometriosis, which raises the risk for heart disease in younger women
  • Gestational diabetes, which can raise the risk for diabetes and metabolic syndrome even after pregnancy and the risk of developing coronary heart disease
  • Polycystic ovary syndrome
  • Preeclampsia, a condition that can happen during pregnancy and is linked to an increased lifetime risk for coronary heart disease
  • Early menopause (before age 40)

You should start getting screening tests and risk assessments for coronary heart disease around age 20 if you do not have any risk factors for coronary heart disease. Children may need screening if they have risk factors, such as obesity, low levels of physical activity, or a family history of heart problems.

Afterward, your doctor may recommend preventive treatments such as heart-healthy lifestyle changes to help you lower your risk of coronary heart disease.

How to prevent coronary heart disease

Work with your doctor to set up a plan that works for you based on your lifestyle, your home and neighborhood environments, and your culture. Working with a team of healthcare providers may help with making changes in your diet, being physically active, managing other medical conditions, and helping you quit smoking.

Some people have severe symptoms of coronary heart disease. Others have no symptoms at all. If you have “silent” coronary heart disease, you may not have any symptoms until you have a heart attack or other complication.

Signs and symptoms

An acute coronary event, such as a heart attack, may cause the following symptoms:

  • Angina, which can feel like pressure, squeezing, burning, or tightness during physical activity. The pain or discomfort usually starts behind the breastbone, but it can also occur in the arms, shoulders, jaw, throat, or back. The pain may feel like indigestion.
  • Cold sweats
  • Dizziness
  • Light-headedness
  • Nausea or a feeling of indigestion
  • Neck pain
  • Shortness of breath, especially with activity
  • Sleep disturbances
  • Weakness

Women are somewhat less likely than men to experience chest pain. Instead, they are more likely to experience:

  • Dizziness
  • Fatigue
  • Nausea
  • Pressure or tightness in the chest
  • Stomach pain

Women are also more likely than men to have no symptoms of coronary heart disease.

Chronic (long-term) coronary heart disease can cause symptoms such as the following:

  • Angina
  • Shortness of breath with physical activity
  • Fatigue
  • Neck pain

The symptoms may get worse as the buildup of plaque continues to narrow the coronary arteries. Chest pain or discomfort that does not go away or happens more often or while you are resting might be a sign of a heart attack. If you do not know whether your chest pain is angina or a heart attack, call 9-1-1 right away. All chest pain should be checked by a doctor.

Your doctor will diagnose coronary heart disease based on your symptoms, your medical and family history, your risk factors, and the results from tests and procedures.

Because women and their doctors may not recognize coronary heart disease symptoms that are different from men’s, women may not be diagnosed and treated as quickly as men. It is important to seek care right away if you have symptoms of coronary heart disease.

Medical history

Your doctor will ask about your eating and physical activity habits, your medical history, your family history, and risk factors for coronary heart disease. Your doctor may ask whether you have any other signs or symptoms. This information can help your doctor determine whether you have complications or other conditions that may cause coronary heart disease.

Diagnostic tests and procedures

To diagnose coronary heart disease, your doctor may order some of the following tests.

  • Blood tests to check the levels of cholesterol, triglycerides, sugar, lipoproteins, or proteins, such as C-reactive protein, that are a sign of inflammation.
  • Electrocardiogram (EKG or ECG) to determine whether the heart’s rhythm is steady or irregular. An EKG also records the strength and timing of electrical signals as they pass through the heart.
  • Coronary calcium scan to measure the amount of calcium in the walls of your coronary arteries. Buildup of calcium can be a sign of atherosclerosis, coronary artery disease, or coronary microvascular disease. This test is a type of cardiac CT scan. Coronary calcium scans can also help assess coronary heart disease risk for people who smoke or for people who do not have heart symptoms.
  • Stress tests to check how your heart works during physical stress. During stress testing, you walk or run on a treadmill or pedal a stationary bike to make your heart work hard and beat fast. If you have a medical problem that prevents you from exercising, your doctor may give you medicine to make your heart work hard, as it would during exercise. To detect reduced blood flow to your heart muscle, while you exercise you will be monitored by ECG and possibly echocardiogram or a CT scan.
  • Cardiac MRI (magnetic resonance imaging) to detect tissue damage or problems with blood flow in the heart or coronary arteries. It can help your doctor diagnose coronary microvascular disease or nonobstructive or obstructive coronary artery disease. Cardiac MRI can help explain results from other imaging tests such as chest X-rays and CT scans.
  • Cardiac positron emission tomography (PET) scanning to assess blood flow through the small coronary blood vessels and into the heart tissues. This is a type of nuclear heart scan that can diagnose coronary microvascular disease.
  • Coronary angiography to show the insides of your coronary arteries. To get the dye into your coronary arteries, your doctor will use a procedure called cardiac catheterization. This procedure is often used if other tests show that you are likely to have coronary artery disease. To diagnose coronary microvascular disease, your doctor will use coronary angiography with guidewire technology. A guidewire with sensors is inserted into the heart’s arteries. The sensors measure how easily blood flows through the small vessels. Usually, measurements are done before and after giving you medicine to enhance blood flow in your heart.
  • Coronary computed tomographic angiography to show the insides of your coronary arteries rather than an invasive cardiac catheterization. It is a noninvasive imaging test using CT scanning.

If you have coronary heart disease risk factors, your doctor may recommend diagnostic tests even if you do not have symptoms.

Nonobstructive coronary artery disease and coronary microvascular disease can be missed because patients or doctors may not recognize the warning signs. Diagnosing these types often requires more invasive tests or specialized tests, such as cardiac PET scans, that are not widely available.

Your treatment plan depends on how severe your disease is, the severity of your symptoms, and any other health conditions you may have. Possible treatments for coronary heart disease include heart-healthy lifestyle changes, medicines, or procedures such as coronary artery bypass grafting or percutaneous coronary intervention.

Your doctor will consider your 10-year risk calculation when deciding how best to treat your coronary heart disease.

Heart-healthy lifestyle changes

Your doctor may recommend that you adopt lifelong heart-healthy lifestyle changes, including:

  • Aiming for a healthy weight. Losing just 3% to 5% of your current weight can help you manage some coronary heart disease risk factors, such as high blood cholesterol and diabetes. Greater amounts of weight loss can also improve blood pressure readings.
  • Being physically active. Routine physical activity can help manage coronary heart disease risk factors such as high blood cholesterol, high blood pressure, or overweight and obesity. Before starting any exercise program, ask your doctor what level of physical activity is right for you.
  • Heart-healthy eating, such as the DASH (Dietary Approaches to Stop Hypertension) eating plan. A heart-healthy eating plan includes fruits, vegetables, and whole grains and limits saturated fats, trans fats, sodium (salt), added sugars, and alcohol.
  • Managing stress. Learning how to manage stress, relax, and cope with problems can improve your emotional and physical health.
  • Quitting smoking. Visit Smoking and Your Heart and the National Heart, Lung, and Blood Institute’s Your Guide to a Healthy Heart. Although these resources focus on heart health, they include basic information about how to quit smoking. For free help and support to quit smoking, you can call the National Cancer Institute’s Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848). Talk to your doctor if you vape. There is scientific evidence that nicotine and flavorings found in vaping products may damage your heart and lungs.
  • Get enough good-quality sleep. The recommended amount for adults is 7 to 9 hours of sleep a day.
Medicines
  • ACE inhibitors and beta blockers to help lower blood pressure and decrease the heart’s workload.
  • Calcium channel blockers to lower blood pressure by allowing blood vessels to relax.
  • Medicines to control blood sugar, such as empagliflozin, canagliflozin, and liraglutide, to help lower your risk for complications if you have coronary heart disease and diabetes.
  • Metformin to control plaque buildup if you have diabetes.
  • Nitrates, such as nitroglycerin, to dilate your coronary arteries and relieve or prevent chest pain from angina.
  • Ranolazine to treat coronary microvascular disease and the chest pain it may cause.
  • Statins and/or non-statin therapies to control high blood cholesterol. Your doctor may recommend statin therapy if you have a higher risk for coronary heart disease or stroke or if you have diabetes and are between ages 40 and 75. Non-statin therapies may be used to reduce cholesterol when statins do not lower cholesterol enough or cause side effects. Your doctor may prescribe non-statin drugs, such as, ezetimibe, bile acid sequestrants, alirocumab, or evolocumab to lower cholesterol or omega-3 fatty acids, gemfibrozil, or fenofibrate to reduce triglycerides.