What Are Atherosclerosis and Cardiovascular Disease?
Cardiovascular disease (CVD) is a broad term used to describe a range of diseases that involve the heart or blood vessels. While there are a number of cardiovascular diseases, the term generally refers to conditions related to atherosclerosis (arterial disease), in which artery walls thicken as a result of the accumulation of fatty materials such as cholesterol. Over the years, the medical community has discovered a number of cardiovascular disease risk factors and has developed new strategies for effective treatment and prevention of cardiovascular disease. Despite these gains, cardiovascular disease is the leading cause of death globally; it accounted for approximately 17.3 million deaths in 2008. Low-and middle-income countries are disproportionally affected as over 80 percent of cardiovascular disease deaths occur in these countries.2
What Causes Atherosclerosis and Cardiovascular Disease?
While the exact cause of atherosclerosis is unknown, studies show that the disease starts with damage to the inner layers of the arteries. This arterial damage may be caused by a number of factors, including high blood pressure, smoking and high cholesterol. Over time, these factors damage the endothelium, the layer of cells that line the walls of the blood vessels and capillaries.
Referred to as the “brain” of the vascular system, the endothelium is essential to ensuring that blood flows properly throughout the body while preventing toxic substances from penetrating the blood vessels. As the factors described above damage the endothelium, it eventually leads to endothelial dysfunction, a condition that has been shown not only to be significant in predicting stroke and heart attacks3 but also to be an early indicator of subclinical atherosclerosis.4
Atherosclerosis usually develops slowly over many years—sometimes starting in childhood—and causes no symptoms until middle age or older. This suggests that there likely are a large number of asymptomatic adults who are unwittingly at risk of a cardiac event. In fact, clinical researchers have estimated that approximately 40% of U.S. adults without symptoms of coronary heart disease are at moderate risk of a cardiac event and 25% of asymptomatic U.S. adults are at high risk of a cardiac event. 5
Major Risk Factors Associated with Atherosclerosis1
- Unhealthy blood cholesterol levels. This includes high LDL cholesterol (sometimes called "bad" cholesterol) and low HDL cholesterol (sometimes called "good" cholesterol).
- High blood pressure. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)
- Smoking. Smoking can damage and tighten blood vessels, raise cholesterol levels, and raise blood pressure. Smoking also doesn't allow enough oxygen to reach the body's tissues.
- Insulin resistance. This condition occurs if the body can't use its insulin properly. Insulin is a hormone that helps move blood sugar into cells where it's used as an energy source. Insulin resistance may lead to diabetes.
- Diabetes. With this disease, the body's blood sugar level is too high because the body doesn't make enough insulin or doesn't use its insulin properly.
- Overweight or obesity. The terms "overweight" and "obesity" refer to body weight that's greater than what is considered healthy for a certain height.
- Lack of physical activity. A lack of physical activity can worsen other risk factors for atherosclerosis, such as unhealthy blood cholesterol levels, high blood pressure, diabetes, and overweight and obesity.
- Unhealthy diet. An unhealthy diet can raise your risk for atherosclerosis. Foods that are high in saturated and trans fats, cholesterol, sodium (salt), and sugar can worsen other atherosclerosis risk factors.
- Older age. As you get older, your risk for atherosclerosis increases. Genetic or lifestyle factors cause plaque to build up in your arteries as you age. By the time you're middle-aged or older, enough plaque has built up to cause signs or symptoms. In men, the risk increases after age 45. In women, the risk increases after age 55.
- Family history of early heart disease. Your risk for atherosclerosis increases if your father or a brother was diagnosed with heart disease before 55 years of age, or if your mother or a sister was diagnosed with heart disease before 65 years of age.
Treatment and Prevention of Atherosclerosis and CVD
Atherosclerosis can be prevented and to some extent cured through basic lifestyle changes, including:
- Avoid fatty foods. A well-balanced diet that includes fruits, vegetables and whole grains that are low in fat and cholesterol is important for reducing your risk of atherosclerosis. Adding fish, broiled or baked, to your diet at least twice a week may be helpful.6
- Stop smoking. Smoking damages your arteries and can raise cholesterol level and blood pressure. If you smoke, quitting is important to halt the progression of atherosclerosis and reduce your risk of complications.7
- Exercise routinely. Daily exercise not only helps to lower blood pressure and reduce risk of diabetes, but it also conditions your muscles to use oxygen more efficiently. Ideally, you should exercise for 30 minutes a day if you are normal weight, and for 60-90 minutes a day if you are overweight.8,9
- Manage stress. Reducing work-and home-related stress is important for maintaining a healthy heart. There are a number of techniques for reducing stress, such as muscle relaxation and deep breathing exercises.
- Monitor blood pressure. You should have your blood pressure checked every 1-2 years before age 50 and yearly after age 50. If your blood pressure is high, it is important to work with your doctor to understand your health risks and to develop a plan for managing the condition.10
Various kinds of medications are recommended for people with atherosclerosis. The following is a list of some common choices:
- Cholesterol medications. There are a variety of cholesterol medications available, such as statins and fibrates. Statins help to lower low-density lipoprotein (LDL) cholesterol, the “bad” cholesterol, thereby stopping or reversing the buildup of fatty deposits in your arteries.11 Fibrates lower blood triglyceride levels and helps to increase high-density lipoprotein (HDL) cholesterol, the “good” cholesterol, in your body.12
- Anti-platelet medications. Antiplatelets are medications that prevent blood particles called platelets from clumping together, forming harmful blood clots and causing further blockage in arteries. These medications may be given to people who have had a heart attack or experienced certain heart conditions, such as angina or stroke. Aspirin is one common type of antiplatelet medicine. 13
- Beta Blocker medications. These medications lower the heart rate and blood pressure. They are commonly used to treat coronary artery disease, high blood pressure and some heart arrhythmias. They can also be used to delay or prevent the development of angina. 14
- Angiotensin-converting enzyme (ACE) inhibitors. These medications stop the body from producing a chemical that narrows blood vessels, thereby lowering blood pressure and reducing risk of atherosclerosis. ACE inhibitors may also reduce the risk of future heart attacks.15
- Calcium channel blockers. These medications work to lower blood pressure by relaxing the blood vessels. They also are sometimes used to treat angina and some types of heart arrhythmias.16
- Water pills (diuretics). Diuretics decrease fluid buildup in the body and are effective in lowering high blood pressure. In addition, recent research shows that diuretics may help to prevent stroke, heart attack and heart failure.17
Surgical treatment may be needed for patients with advanced atherosclerosis. These operations may be required for patients who have severe symptoms or a blockage that threatens muscle or skin tissue survival. Examples of such procedures include:
- Angioplasty. This procedure is used to open blocked or narrowed coronary arteries. Angioplasty can improve blood flow to the heart, relieve chest pain, and possibly prevent a heart attack. In most cases, a stent is placed in the artery to help keep the artery open. 18
- Endarterectomy. This procedure involves the surgical removal of plaque from the walls of an artery that has become blocked or narrowed. In this procedure, a vascular surgeon makes an incision in the patient’s affected artery and removes the plaque contained in the artery’s inner lining to restore blood flow. 19
- Thrombolytic therapy. If you have an artery that’s blocked by a blood clot, your physician may inject clot-dissolving medication into a blood vessel. In some cases, physicians may use a long, thin tube, called a catheter, to deliver medications or mechanically break up the clot.20
- Bypass surgery. In this procedure, a doctor creates a graft bypass using arteries or veins from other areas of the body or a tube made of synthetic fabric. This enables blood to flow around the blocked or narrowed artery.21
- National Heart Lung and Blood Institute
- Improving Coronary Heart Disease Risk Assessment in Asymptomatic People Greenland P, Smith S, Grundy S. Circulation. 2001; 104: 1863-1867