Coronary heart disease (CHD) is a narrowing of the small blood vessels that supply blood and oxygen to the heart. CHD is also called coronary artery disease.

See also:

• Angina
• Heart attack
• Unstable angina

Coronary heart disease is usually caused by a condition called atherosclerosis, which occurs when fatty material and a substance called plaque build up on the walls of your arteries. This causes them to get narrow. As the coronary arteries narrow, blood flow to the heart can slow down or stop. This can cause chest pain (stable angina), shortness of breath, heart attack, and other symptoms.

Coronary heart disease (CHD) is the leading cause of death in the United States for men and women.

Many things increase your risk for heart disease:

• Men in their 40s have a higher risk of CHD than women. But as women get older (especially after they reach menopause), their risk increases to almost equal that of a man's risk. See: Heart disease and women
• Bad genes (heredity) can increase your risk. You are more likely to develop the condition if someone in your family has had a history of heart disease -- especially if they had it before age 50. Your risk for CHD goes up the older you get.
• Diabetes is a strong risk factor for heart disease.
• High blood pressure increases your risk of coronary artery disease and heart failure.
• Abnormal cholesterol levels: your LDL ("bad") cholesterol should be as low as possible, and your HDL ("good") cholesterol should be as high as possible.
• Metabolic syndrome refers to high triglyceride levels, high blood pressure, excess body fat around the waist, and increased insulin levels. People with this group of problems have an increased chance of getting heart disease.
• Smokers have a much higher risk of heart disease than nonsmokers.
• Chronic kidney disease can increase your risk.
• Already having atherosclerosis or hardening of the arteries in another part of your body (examples are stroke and abdominal aortic aneurysm) increases your risk of having coronary heart disease.
• Other risk factors including alcohol abuse, not getting enough exercise, and excessive amounts of stress.

Higher-than-normal levels of inflammation-related substances, such as C-reactive protein and fibrinogen are being studied as possible indicators of an increased risk for heart disease.

Increased levels of a chemical called homocysteine, an amino acid, are also linked to an increased risk of a heart attack.

Symptoms may be very noticeable, but sometimes you can have the disease and not have any symptoms.

Chest pain or discomfort (angina) is the most common symptom. You feel this pain when the heart is not getting enough blood or oxygen. How bad the pain is varies from person to person.

• It may feel heavy or like someone is squeezing your heart. You feel it under your breast bone (sternum), but also in your neck, arms, stomach, or upper back.
• The pain usually occurs with activity or emotion, and goes away with rest or a medicine called nitroglycerin.
• Other symptoms include shortness of breath and fatigue with activity (exertion).

See: Heart failure for symptoms of heart failure

Many tests help diagnose CHD. Usually, your doctor will order more than one test before making a definite diagnosis.

Tests may include:

• Electrocardiogram (ECG)
• Exercise stress test
• Echocardiogram
• Nuclear scan
• Electron-beam computed tomography (EBCT) to look for calcium in the lining of the arteries -- the more calcium, the higher your chance for CHD
• CT angiography -- a noninvasive way to perform coronary angiography
• Magnetic resonance angiography
• Coronary angiography/arteriography -- an invasive procedure designed to evaluate the heart arteries under x-ray

You may be asked to take one or more medicines to treat blood pressure, diabetes, or high cholesterol levels. Follow your doctor's directions closely to help prevent coronary artery disease from getting worse. Goals for treating these conditions in those who have coronary artery disease are:

• LDL cholesterol level less than or equal to 100 mg/dL
• Glycosylated hemoglobin (HbA1c) levels less than or equal to 7%
• Blood pressure less than or equal to 120/80 mmHg

Taking aspirin with or without clopidogrel (Plavix) helps prevent blood clots from forming in your arteries and reduces your risk of having a heart attack. Ask your doctor if you should be taking these.

Treatment depends on your symptoms and how severe the disease is. Your doctor may give you one or more medicines to treat CHD, including:

• ACE inhibitors to lower blood pressure and protect your heart
• Beta-blockers to lower heart rate, blood pressure, and oxygen use by the heart
• Calcium channel blockers to relax arteries, lowering blood pressure and reducing strain on the heart
• Diuretics to lower blood pressure and treat congestive heart failure
• Nitrates (such as nitroglycerin) to stop chest pain and improve blood supply to the heart
• Statins to lower cholesterol

NEVER ABRUPTLY STOP TAKING ANY OF THESE DRUGS. Always talk to your doctor first. Stopping these drugs suddenly can make your angina worse or cause a heart attack.

Procedures and surgeries used to treat CHD include:

• Angioplasty and stent placement, called percutaneous coronary interventions (PCIs)
• Coronary artery bypass surgery
• Minimally invasive heart surgery

Lifestyle changes are very important. Your doctor may tell you to:

• Avoid or reduce the amount of salt (sodium) you eat
• Eat a heart healthy diet -- one that is low in saturated fats, cholesterol, and trans fat
• Get regular exercise and maintain a healthy weight
• Keep your blood sugar strictly under control if you have diabetes
• Stop smoking

See also: Healthy heart diet

Everyone recovers differently. Some people can maintain a healthy life by changing their diet, stopping smoking, and taking medications exactly as the doctor prescribes. Others may need medical procedures such as angioplasty or surgery.

Although everyone is different, early detection of CHD generally results in a better outcome.

• Heart attack
• Heart failure
• Unstable angina
• Sudden death

If you have any of the risk factors for CHD, contact your doctor to discuss prevention and possible treatment.

Immediately contact your health care provider, call the local emergency number (such as 911), or go to the emergency room if you have:

• Angina
• Shortness of breath
• Symptoms of a heart attack

See your health care provider regularly.

Tips for preventing CHD or lowering your risk of the disease:

• Avoid or reduce stress as best as you can.
• Don't smoke.
• Eat well-balanced meals that are low in fat and cholesterol and include several daily servings of fruits and vegetables.
• Get regular exercise. If your weight is considered normal, get at least 30 minutes of exercise every day. If you are overweight or obese, experts say you should get 60 - 90 minutes of exercise every day.
• Keep your blood pressure below 130/80 mmHg if you have diabetes or chronic kidney disease, and below 140/90 otherwise
• Keep your cholesterol and blood sugar under control.

Moderate amounts of alcohol (one glass a day for women, two for men) may reduce your risk of cardiovascular problems. However, drinking larger amounts does more harm than good.

If you have one or more risk factors for coronary heart disease, talk to your doctor about possibly taking an aspirin a day to help prevent a heart attack or stroke. You may be prescribed low-dose aspirin therapy if the benefit is likely to outweigh the risk of gastrointestinal side effects.

New guidelines no longer recommend hormone replacement therapy, vitamins E or C, antioxidants, or folic acid to prevent heart disease. The use of hormone replacement therapy in women who are close to menopause or who have finished menopause is controversial at this time.

Mosca L, Banka CL, Benjamin EJ, et al. Evidence-Based Guidelines for Cardiovascular Disease Prevention in Women: 2007 Update. Circulation. 2007; Published online before print February 19, 2007.

Smith SC Jr, Allen J, Blair SN, et al. AHA/ACC guidelines for secondary prevention for patients with coronary and other atherosclerotic vascular disease: 2006 update: endorsed by the National Heart, Lung, and Blood Institute. Circulation. 2006 May 16;113(19):2363-72. Erratum in: Circulation. 2006 Jun 6;113(22):e847.

Morrow DA, Gersh BJ. Chronic coronary artery disease. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, Pa: Saunders Elsevier;2007: chap 54.

Boden WE, O'rourke RA, Teo KK, et al. Optimal Medical Therapy with or without PCI for Stable Coronary Disease. N Engl J Med. 2007 Mar 26; [Epub ahead of print].

U.S. Preventive Services Task Force. Aspirin for the prevention of cardiovascular disease: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2009;150:396-404.