Coronary Artery Disease (CAD)
Recaldo Gilpin Case Management Article
Coronary artery disease (CAD), also called coronary heart disease, or simply, heart disease, is the most common cardiac disease. CAD is the leading cause of death for both men and women in the United States. Approximately 370,000 Americans are affected by CAD each year.
How does CAD develop?
CAD develops when the major blood vessels that supply the heart with blood, oxygen and nutrients to the coronary arteries become damaged or diseased. Usually, plaque (cholesterol-containing deposits) starts from a young age and continues to build up in the arteries as the person ages causing a condition known as atherosclerosis. As the plaque builds up over many years it can harden or rupture. The hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart.
As the plaque makes the inner walls of the blood vessel sticky, inflammatory cells, lipoproteins, and calcium travel into the bloodstream and mix with the plaque. As more of the inflammatory cells come in contact with cholesterol, the plaque increases, pushing the artery walls outward and growing inward, making the vessels narrower.
Eventually, the narrowed artery may develop new blood vessels that go around the blockage to deliver blood to the heart. However, if the person is stressed or pushing to the limit, the new arteries may not be able to deliver enough oxygen-rich blood to the heart muscle.
In some cases, the plaque ruptures and a blood clot forms and blocks the blood supply to the heart muscles; this can trigger a myocardial infarction. Or, a blood vessel to the brain may become blocked from a blood clot resulting in an ischemic stroke or a hemorrhagic stroke from uncontrolled hypertension.
What is the cause?
The cause of CAD is thought to begin with damage or an injury to the inner layer of the coronary artery. This can start as early as childhood. Damage to the coronary artery may be caused by:
- High cholesterol
- Diabetes or insulin resistance
- Sedentary lifestyle
Once the inner wall of an artery is damaged, plaque and other cellular waste products tend to accumulate at the site resulting in atherosclerosis. If the surface plaque breaks off or ruptures, platelets will clump at the site to try to repair the artery. The platelets can block the artery, leading up to a myocardial infarction.
What are the risk factors?
The major risk factors for CAD can be controlled by taking action to prevent:
- Unhealthy blood cholesterol levels, which is a high LDL (bad cholesterol) and a low HDL (good cholesterol).
- Hypertension is considered if the blood pressure stays at or above 140/90 mmHg over time. Hypertension for people with diabetes or chronic kidney disease is defined as a blood pressure 130/80 mmHg or higher.
- Smoking can damage and tighten blood vessels. It also leads to unhealthy cholesterol levels and raises blood pressure. Smoking can limit how much oxygen reaches the body’s tissues. Also, the exposure of secondhand smoke to others increases their risk of CAD.
- Insulin resistance occurs when the body cannot use its own insulin properly. Insulin is a hormone that helps to move glucose into the cells to use as energy. Insulin resistance may lead to diabetes.
- Diabetes causes blood glucose to rise.
- Overweight or obesity refers to body weight that is greater than what is considered healthy for a certain height and bone structure.
- Metabolic syndrome raises the risk for congestive heart disease, diabetes, stroke, etc.
- Lack of physical activity increases the risk of CAD (e.g. unhealthy blood cholesterol levels, hypertension, diabetes, and being overweight or obese).
- An unhealthy diet increases the risk for CAD (e.g. foods high in saturated and trans- fats, cholesterol, sodium, and sugar).
- Older age, genetics or lifestyle increases the risk of damaged and narrowed arteries, because plaque builds up in the arteries as one ages. In men the risk for CAD increases starting at age 45 and women the risk increases starting at age 55.
- Family history of early CAD is a risk factor, especially if a father or brother is diagnosed before age 55, or a mother or sister is diagnosed before age 65. Although older age and a family history of early heart disease are risk factors, there is no evidence that the person will develop CAD if both, or either parents or siblings, have a diagnosis of CAD. Learning to control other risk factors often times can lessen genetic influences and help prevent CAD, even in older adults.
- Physical inactivity is associated with CAD as well as other risk factors.
- High stress that is not unrelieved may damage the arteries as well as worsen other risk factors for CAD
In general, risk factors often occur in clusters and may build on one another, such as obesity, which is the leading cause to type 2 diabetes and hypertension. When grouping risk factors together such as metabolic syndrome, a person is at greater risk because of the combination including hypertension, high triglycerides, elevated insulin levels, and excess body fat around the waist. Sometimes CAD can occur without any of the classic risk factors.
Other conditions and factors that may contribute to CAD include:
- Sleep apnea if untreated can increase the risk for hypertension, diabetes, myocardial infarct, or stroke.
- Alcohol can damage the heart muscle and cause other CAD risk factors. Men should have no more than two drinks containing alcohol a day. Women should not have more than one drink containing alcohol a day.
- Preeclampsia can occur during pregnancy. The two main signs of preeclampsia are a rise in blood pressure and excess protein in the urine. Preeclampsia is linked to an increased lifetime risk of heart disease, including CAD, myocardial infarct, heart failure, and hypertension.
What are the signs and symptoms?
Initially, a decrease in blood flow may not cause CAD symptoms. However, as plaque continues to build up in the coronary arteries symptoms occur, including:
- Angina is a feeling of pressure or tightness in the chest. The pain usually occurs on the middle or left side of the chest. In general, angina is triggered by physical or emotional stress. Usually, the pain goes away within minutes after the stressful activity ceases. In some people, but especially in women, the pain experienced may be fleeting or sharp and felt in the neck, arm(s), or back. Symptoms of angina can be described as heaviness, pressure, aching, numbness, fullness, squeezing, and painful. Usually, angina is felt in the chest but also can be felt in the left shoulder, arms, neck and back.
- Shortness of breath occurs when the heart cannot pump enough blood to meet the body’s needs. Also, shortness of breath or extreme fatigue can occur with exertion.
- Myocardial infarct can occur when the coronary artery is completely blocked. The classic symptoms are crushing pressure in the chest and pain in the shoulder or arm, sometimes shortness of breath or sweating may occur. In general, women are more likely than men to experience less typical signs and symptoms of a myocardial infarct. Sometimes a myocardial infarct can occur without the following symptoms:
- Palpitations (i.e. irregular heartbeats, skipped beats, or a “flip-flop” feeling in the chest).
- Weakness or dizziness.
- Faster heartbeat.
What are the complications?
CAD can lead to the following complications:
- Myocardial infarct.
- Heart failure can occur when the heart is chronically deprived of oxygen and nutrients, due to reduced blood flow, myocardial infarct, because the heart may be too weak to pump enough blood to meet the body’s needs.
- Arrhythmia or abnormal heart rate occurs when there is an inadequate blood supply to the heart or damage to the heart tissue that can interfere with the heart’s electrical impulses, causing the arrhythmia.
How is CAD diagnosed?
CAD is diagnosed upon completion of a medical history, physical examination, routine blood tests and diagnostic testing. Diagnostic testing may include:
- Electrocardiogram (ECG). An ECG records electrical signals as they travel through the heart. An ECG scan often reveals evidence of a previous myocardial infarction or one that is in progress.
- Echocardiogram. An echocardiogram uses sound waves to produce images of the heart. The echocardiogram will show all segments of the heart wall to determine if the heart’s pumping activity is normal. Segments of the heart that are moving inadequately may have been damaged during a myocardial infarction event or the heart was receiving too little oxygen at the time, which can indicate CAD or another cardiac condition.
- Stress test. When signs and symptoms occur during exercise, an exercise stress test will most likely be recommended. The person may be asked to walk on the treadmill or ride a stationary bike during an ECG. In some instances medication may be used to stimulate the heart instead of exercise. Some stress tests are performed with a medication to stimulate the heart during an echocardiogram and some stress tests may be done using ultrasound before and after using a treadmill or bike. A nuclear stress test may be required to measure blood flow to the heart muscles at rest and during stress. The test is similar to the routine exercise stress test, but with imaging in addition to an ECG. A tracer is injected into the bloodstream and special cameras are used to detect areas in the heart that receive less blood flow.
- Cardiac catheterization. A cardiac catheterization, also known as an angiogram, views blood flow through the heart. A dye may be injected into the coronary arteries through a flexible catheter that is threaded through an artery, usually the leg, to the arteries in the heart. The dye will outline narrow spots and blockages on the x-ray images. If the blockage requires treatment, a balloon can be passed through the catheter and inflated to improve blood flow in the coronary arteries. A mesh stent may be used to keep the artery open.
- Heart scan is a computerized tomography (CT) used to detect calcium deposits in the arteries that can narrow the arteries. If there is a substantial amount of calcium, CAD may be likely. A CT coronary angiogram is a test using a contrast dye that is injected intravenously during a CT scan to generate images of the heart arteries.
What is the treatment?
Usually, the treatment for coronary artery disease involves lifestyle changes, sometimes medications may be prescribed and certain medical procedures may be recommended such as: angioplasty and stent placement, also known as percutaneous coronary revascularization and/or coronary artery bypass surgery.
Promote healthier arteries by committing to living a healthier lifestyle:
- Quit smoking, smoking can increase the risk for CAD and myocardial infarction. It can also increase the risk of other heart disease. It is also important to avoid secondhand smoke.
- Heart healthy eating should include:
- Fat-free or low fat dairy products (i.e. fat-free milk).
- Fish high in omega – 3 fatty acids (i.e. salmon, tuna, and trout twice a week).
- Fruits (i.e. apples, bananas, oranges, pears, and prunes).
- Legumes (i.e. kidney beans, lentils, chickpeas, black-eyed peas, and lima beans).
- Vegetables (i.e. broccoli, cabbage, and carrots).
- Whole grains (i.e. oatmeal, brown rice, and corn tortillas).
The following foods should be avoided on a heart healthy diet:
- A lot of red meat.
- Palm and coconut oils.
- Sugary beverages and foods
There are two nutrients that can cause blood cholesterol levels to rise; they are saturated fats (mostly found in foods that come from animals) and Trans fats (found in hydrated oils and fats such as stick margarine, baked goods, coffee creamers and some that occur naturally in animal fats and meats).
Saturated fats raise blood cholesterol more than anything else in the diet. A heart-healthy diet should not contain more than 5 to 6 percent of daily calories coming from saturated fat. However, not all fats are bad. Monounsaturated and polyunsaturated fat actually help to lower blood cholesterol levels. Some examples of monounsaturated and polyunsaturated fats are avocados, corn, sunflower and soybean oils, nuts and seeds (i.e. walnuts), olive, canola, peanut, safflower, and sesame oils, peanut butter, salmon and trout; and tofu.
Sodium should be limited to no more than 2,300 milligrams of sodium a day. People who have high blood pressure will need to restrict sodium intake to less than 2,300 milligrams a day. The treating physician may recommend following the DASH diet, which is a heart healthy eating plan.
- Limit alcohol intake to know more than two drinks for men a day and no more than one drink for women a day. One drink is either 12 ounces of beer, 5 ounces of wine, or 1 ½ ounces of liquor. Alcohol can raise blood pressure and triglyceride levels if too much is consumed. Alcohol also adds extra calories, which can cause weight gain.
- Exercising regularly can lower many CAD risk factors, including LDL cholesterol, hypertension, and excess weight. Physical activity can help to lower the risk for diabetes and raise HDL cholesterol level to prevent CAD. It is important to participate in moderate-intensity aerobic exercise at least 2 hours and 30 minutes per week, or a vigorous aerobic exercise program for 1 hour and 15 minutes per week (e.g. brisk walking).
- Maintaining a healthy weight is important for overall health to lower the risk of CAD. The aim is to reach and maintain a healthy weight by following a heart healthy diet and keeping physically active. Knowing one’s body mass index (BMI) helps to define a healthy weight in relation to height and estimate of total body fat. According to National Heart, Lung, and Blood Institute’s (NHL). A BMI is:
- Below 18.5 is a sign the person is underweight.
- Between 18.5 and 24.9 is in the normal range.
- Between 25 and 29.9 is considered overweight
- 30 or above is considered obese.
In general, the goal is to aim for a BMI of less than 25. If your BMI is 25 and above speak with the physician or health care provider to set an appropriate BMI goal.
Waist circumference screening is also important to prevent possible risk factors for those with a waist circumference size that is greater than 35 inches for women, or greater than 40 inches for men, to prevent type 2 diabetes and heart disease. A loss of 3 to 5 percent of a person’s current weight can lower a person’s triglycerides, blood glucose, and the risk of developing type 2 diabetes. The greater the weight loss the greater it can improve blood pressure readings, lower LDL cholesterol, and increase HDL cholesterol.
- Reduce stress through relaxation techniques that teach how to use coping skills to improve emotional and physical health. Some healthy stress-reducing activities to reduce “triggers” are:
- Stress management program.
- Physical activity.
- Relaxation therapy.
- Speaking with friends and family.
Why medications to treat CAD?
There are times that changing one’s lifestyle is not enough to control blood cholesterol levels and statin medication may be needed to control or lower blood cholesterol levels. By lowering the blood cholesterol level, one can decrease the chance of having a myocardial infarct or cerebral vascular accident (stroke).
Usually, physicians prescribe statins for people who are at risk for developing cardiac disease or cerebral vascular accident.
Also, the treating physician may prescribe additional medications to:
- Decease the incident of a myocardial infarct or sudden death.
- Lower blood pressure.
- Prevent thrombosis (blood clots), which can lead to myocardial infarction or cerebral accident.
- Prevent or delay the need for a stent or percutaneous coronary intervention (PCI) or surgery, such as a coronary artery bypass grafting (GABG).
- Reducing the heart’s workload and lessen CAD symptoms.
It is important to take medication regularly as prescribed and not modify the dose or skip taking the medication.
The following medications may be recommended to treat CAD:
- Cholesterol-modifying medications such as statins, niacin, fibrates and bile acid sequestrates may be prescribed to decrease the amount of cholesterol in the blood, especially LDL (low-density lipoprotein, the bad cholesterol) to decrease plaque deposits on the coronary arteries.
- Aspirin may be recommended to take daily or another blood thinner to reduce the tendency of the blood to clot. The aspirin may help to prevent obstruction of the coronary arteries. Aspirin can help to prevent future myocardial infarctions for those who have experienced a myocardial infarct in the past. Aspirin may not be appropriate for everyone if there is a history of a bleeding disorder or they are on another anticoagulant.
- Beta blockers are medications that slow the heart rate down and decrease blood pressure to increase the heart’s demand for oxygen. Beta blockers help to reduce the risk of myocardial infarctions for those at risk of future myocardial infarctions.
- Nitroglycerin tablets, sprays and patches can control chest pain by temporarily dilating the coronary arteries to provide the heart’s demand for blood.
- Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) help to decrease blood pressure and prevent progression of coronary artery disease.
There are two aggressive surgical procedures available to restore and improve blood flow. They are as follows:
- Angioplasty and stent placement, also known as percutaneous coronary revascularization. This is a nonsurgical procedure that opens blocked or narrowed coronary arteries to restore blood flow through the artery.
- Coronary artery bypass surgery is open heart surgery and is often times reserved for multiple narrowed coronary arteries. The surgeon creates a graft to bypass blocked coronary arteries using a vessel from another part of the body allowing the blood to flow around the blocked or narrow coronary arteries.
Why cardiac rehabilitation?
Cardiac rehabilitation may be prescribed for angina or after coronary artery bypass surgery, angioplasty, or a myocardial infarct. Cardiac rehabilitation is a medically supervised program designed to improve the health and well-being of people with cardiac conditions.
The cardiac rehabilitation team includes physicians, nurses, exercise specialists, physical and occupational therapists, dieticians or nutritionists, and psychologists, or other mental health specialists.
The cardiac rehabilitation consists of two parts:
- Cardiac rehabilitation helps the person understand CAD and ways to reduce the risk of future cardiac conditions through education, counseling, and training. Also, the team assists the person in learning to cope with stress, adjust to a new style of living, and how to deal with fears about the future.
- Exercise training helps the person to learn how to exercise safely, strengthen muscles, to improve stamina, which is all based on the person’s individual abilities, needs, and interests.
Why the need for lifestyle changes and emotional support?
Living with CAD may present with fear, anxiety, and stress, which has an impact on a person’s activities of daily living and positive outcomes. Speaking with the health care team or a professional counselor about concerns such as feeling depressed is important to address to maintain optimum health. If depressed, the physician may recommend taking medication to treat the depression or recommend an alternative treatment to improve one’s quality of life.
Joining a support group may help in adjusting to living with CAD. Generally, people in the support group may be experiencing some or all of the same symptoms or concerns and can offer suggestions on how to cope. Also, support from family and friends may help to decrease the stress and anxiety one is going through. Also, it is important to be open to loved ones about how one feels and what they can do to help.