Coronary Heart Disease

Also known as Coronary Artery Disease, Coronary Microvascular Disease, Coronary Syndrome X, Ischemic Heart Disease, Nonobstructive Coronary Artery Disease, Obstructive Coronary Artery Disease.

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.

Causes of Coronary Heart Disease

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

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.

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 affecting the blood vessels

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.

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.

Risk Factors

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

Genetic or lifestyle factors cause plaque to build up in your arteries as you age. In men, the risk for coronary heart disease starts to increase around age 45. Before menopause, women have a lower risk of coronary heart disease than men. After around age 55, women’s risk goes up. This is likely because women make less estrogen (a female hormone) after menopause. Also, changes in the small blood vessels of the heart as you age raise the risk for coronary microvascular disease.

Environment and occupation

Air pollution in the environment can put you at higher risk of coronary heart disease. The increase in risk may be higher in older adults, women, and people who have diabetes or obesity. Air pollution may cause or worsen other conditions, such as atherosclerosis and high blood pressure, which are known to increase your risk for coronary heart disease.

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

Family history and genetics

A family history of early heart disease is a risk factor for coronary heart disease. This is especially true if your father or brother was diagnosed before age 55, or if your mother or sister was diagnosed before age 65. Research shows that some genes are linked with a higher risk for coronary heart disease.

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.
• 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.

Other medical conditions

Other medical conditions that can raise your risk of developing coronary heart disease include:

• Atherosclerosis
• Autoimmune and inflammatory diseases such as Crohns disease, ulcerative colitis, psoriasis, lichen planus, pemphigus, histiocytosis, lupus erythematosus, and rheumatoid arthritis
• Chronic kidney disease
• Congenital coronary artery defects
• Diabetes
• High blood LDL cholesterol (sometimes called “bad cholesterol”)
• High blood pressure
• High blood triglycerides
• HIV/AIDS, especially among older adults. Part of the risk might be due to side effects of HIV treatments.
• Mental health conditions, including anxiety, depression, and posttraumatic stress disorder (PTSD)
• Metabolic syndrome
• Overweight and obesity
• Sleep disorders, such as sleep apnea or sleep deprivation and deficiency

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)

Signs, Symptoms, and Complications

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.

Complications

Coronary heart disease can cause serious complications, including the following:

• Acute coronary syndrome, including angina or heart attack
• Arrhythmia
• Heart failure
• Cardiogenic shock
• Sudden cardiac arrest

Complications of coronary heart disease can be life-threatening and may lead to disability.

Treating Coronary Heart Disease

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

Your doctor may recommend medicines to manage your risk factors or treat underlying causes of coronary heart disease. Some medicines can reduce or prevent chest pain and manage other medical conditions that may be contributing to your coronary heart disease.

• 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 therapiesto 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 therapiesmay 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.

Procedures

You may need a procedure or heart surgery to treat more advanced coronary heart disease.

• Percutaneous coronary intervention (PCI) to open coronary arteries that are narrowed or blocked by the buildup of atherosclerotic plaque. A small mesh tube called a stent is usuallyimplanted after PCI to prevent the artery from narrowing again.
• Coronary artery bypass grafting (CABG) to improve blood flow to the heart by using normal arteries from the chest wall and veins from the legs to bypass the blocked arteries. Surgeons typically use CABG to treat people who have severe obstructive coronary artery disease in multiple coronary arteries.
• Transmyocardiallaser revascularization or coronary endarterectomy to treat severe angina associated with coronary heart disease when other treatments are too risky or did not work.