Coronary artery disease; Coronary heart disease; CHD; CAD
Coronary heart disease (or coronary artery disease) is a narrowing of the small blood vessels that supply blood and oxygen to the heart (coronary arteries). Coronary disease usually results from the build up of fatty material and plaque (atherosclerosis). As the coronary arteries narrow, the flow of blood to the heart can slow or stop. The disease can cause chest pain (stable angina), shortness of breath, heart attack, or other symptoms.
Causes, incidence, and risk factors
Coronary heart disease (CHD) is the leading cause of death in the United States for men and women. According to the American Heart Association, about every 29 seconds someone in the US suffers from a CHD-related event, and about every minute someone dies from such event. The lifetime risk of having coronary heart disease after age 40 is 49% for men and 32% for women. As women get older, the risk increases almost to that of men. (See also heart disease and women.)
There are many factors which increase the risk for CHD. Some of the risks are based on family history (genetics), and others are more controllable. Risk factors include the following:
- Family history of coronary heart disease (especially before age 50)
- Male gender
- Age (65 and greater)
- Tobacco smoking
- High blood pressure
- High cholesterol levels (specifically, high LDL cholesterol and low HDL cholesterol)
- Lack of physical activity or exercise
- High blood homocysteine levels
- Menopause in women
- Infection that causes inflammatory response in the artery wall. (There is some evidence that suggests this, but the theory is being studied.)
The symptoms associated with coronary heart disease may be pronounced, but they can also occur without any noticeable symptoms.
Chest pain (angina) is the most common symptom, and it results from the heart not getting enough blood or oxygen. The intensity of the pain varies from person-to-person. Chest pain may be typical or atypical. Typical chest pain is felt under the sternum and is characterized by a heavy or squeezing feeling, it is precipitated by exertion or emotion, and it is relieved by rest or nitroglycerin.
Atypical chest pain can be located in the left chest, abdomen, back, or arm and is fleeting or sharp. Atypical chest pain is unrelated to exercise and is not relieved by rest or nitroglycerin. Atypical chest pain is more common in women.
The typical nature of the chest pain and the person’s age are indicators of the chances of having CHD. For example, a 65-year-old woman with typical angina has a 91% chance of having CHD, while a 55-year-old woman with atypical angina has a 32% chance of having CHD.
Other symptoms include:
- Shortness of breath - This is usually a symptom of congestive heart failure. The heart at this point is weak because of the long-term lack of blood and oxygen, or sometimes from a recent or past heart attack. If the heart is not pumping enough blood to circulate in the body, shortness of breath may be accompanied by swollen feet and ankles.
- Heart attack - In some cases, the first sign of CHD is a heart attack. This occurs when atherosclerotic plaque or a blood clot blocks the blood flow of the coronary artery to the heart. The coronary artery was likely already narrowed from CHD. The pain associated with a heart attack is usually severe, lasts longer than the chest pain described above, and is not relieved by resting or nitroglycerin.
Signs and tests
There are many tests that may help to diagnose CHD. Usually, more than one test will be done before a definitive diagnosis can be made. Some of the tests include:
- Electrocardiogram (ECG)
- Exercise stress test
- Nuclear scan
- Coronary angiography/arteriography
- Electron-beam computed tomography (EBCT) - the purpose of this test is to identify calcium within the plaque found in the arteries. The more calcium seen, the higher the likelihood for CHD.
The treatment for CHD varies depending on the symptoms and how much the disease has progressed. The general treatments include lifestyle changes, medications, and sometimes surgery.
Lifestyle changes may include:
- Losing weight
- A low saturated fat, low cholesterol diet to help reduce cholesterol
- Reducing sodium (i.e., salt) to keep high blood pressure under control
- Regular exercise
- Quitting smoking
Medications may include:
- Cholesterol-lowering medication
- Antiplatelet agents, such as aspirin, ticlopidine, or clopidogrel, to reduce the risk of blood clots
- Glycoprotein IIb-IIIa inhibitors, such as abciximab, eptifibatide, or tirofiban, to reduce the risk of blood clots
- Antithrombin drugs, such as blood-thinners (low-molecular heparin, unfractionated heparin), to reduce the risk of blood clots
- Beta-blockers to decrease heart rate and lower oxygen use by the heart
- Nitrates such as nitroglycerin to dilate the coronary arteries and improve blood supply to the heart
- Calcium-channel blockers to relax the coronary arteries and all systemic arteries and thus reduce the workload for the heart
- ACE inhibitors, diuretics, or other medications to lower blood pressure
Percutaneous Coronary Interventions (PCI’s) include:
- Coronary angioplasty (Balloon PTCA)
- Coronary atherectomy
- Ablative laser-assisted angioplasty
- Catheter-based thrombolysis and mechanical thrombectomy
- Coronary stenting (placing a tube in the artery to keep it open)
- Coronary radiation implant or coronary brachytherapy
Coronary brachytherapy consists of delivering beta or gamma radiation into the coronary arteries. This new treatment is reserved for patients who have undergone stent implantation in a coronary artery and but developed problems, such as diffuse in-stent restenosis. Brachytherapy is a promising technique but is currently limited by certain complications. In addition, the long-term effects of radiation are unknown, as coronary brachytherapy was only approved by the FDA in late 2000. FDA approval of brachytherapy is currently restricted to treatment of stent-related problems, although in some medical centers brachytherapy is being studied as a first-line treatment of coronary disease.
Surgical procedures include:
- Coronary artery bypass surgery
- Minimally invasive heart surgery
The outcome is variable. Some people can maintain a healthy life by changing diet, stopping smoking, and taking medications as long as they are closely monitored. Others may require more drastic measures, such as surgery. Everyone is different, but one important caveat is detecting CHD early and treating it appropriately.
- Heart attack
- Unstable angina
- Sudden death
Calling your health care provider
If you have any of the risk factors for CHD, you should contact your health care provider for appropriate prevention and treatment. If you experience angina, shortness of breath, or symptoms of a heart attack, contact your health care provider, call 911 or go to the emergency room immediately.
- See your health care provider regularly.
- Don’t smoke.
- Eat a low fat, low cholesterol diet.
- Eat well-balanced meals that include several daily servings of fruits and vegetables.
- Develop a routine exercise regimen. Short, frequent sessions of exercise are preferable to a complete sedentary lifestyle. Walking instead of driving, taking the stairs instead of the elevator, and parking far from building entrances are all measures that most people can incorporate into their busy routines.
- Keep blood pressure under control.
- Maintain weight appropriate for your frame and build.
- Inquire about what vitamin supplements may be helpful in the prevention of CHD.
- Manage stress.
by Sharon M. Smith, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.