Enhanced external counterpulsation (EECP) is a noninvasive procedure in which a set of inflatable cuffs (much like blood pressure cuffs) mechanically compress the blood vessels in the patient's lower limbs to increase blood flow in the coronary arteries of the heart. The blood pressure cuffs are wrapped around the patient's calves, thighs, and buttocks. Computer technology, electrocardiography, and blood pressure monitors enable the accurate timing of gentle but firm inflation and deflation of the pressure cuffs with the patient's heartbeat and blood pressure.
Purpose
EECP is performed to restore blood flow to the heart and to relieve chest pain (angina) and ischemia. The goals of the procedure are to relieve symptoms of coronary artery disease, enable the patient to resume a normal lifestyle, and lower the risk of a heart attack or other heart problems. EECP may encourage blood vessels to open small channels (called collaterals) to eventually bypass blocked vessels and improve blood flow to the heart.
Demographics
The concept of counterpulsation is not new (it was first introduced in the late 1950s at Harvard), but the computerized technology currently available with EECP makes it a relatively new procedure, introduced less than 10 years ago. As of 2003 it is available in only about 200 centers across the United States.
EECP is not the first-line treatment for angina. Rather, it is reserved for patients who have not achieved good results from medication or interventional management of their symptoms.
While the patient lies on a bed, the leg cuffs are deflated and inflated with each heartbeat. A computer synchronizes the compression of the cuffs with the heartbeat. The electrocardiogram indicates when each heartbeat begins, triggering the cuffs to be mechanically deflated. As each heartbeat ends, the cuffs are mechanically inflated in sequential order, starting with the cuffs on the calves and working upward. The pressure produced by the inflation of the cuffs when the heart is at rest pushes the blood in the legs upward toward the heart. The deflating action that occurs just when the heart begins to beat reduces the work of the heart as it pumps blood to other parts of the body.
EECP treatments are performed on an outpatient basis and generally last one to two hours. Treatments must be repeated about five times a week for up to seven weeks to achieve improved circulation.
Preparation
The patient is usually instructed to wear tight-fitting, seamless cycling pants or athletic tights to prevent chafing, one of the main adverse side effects.
Before the procedure, the patient's weight, blood pressure, pulse, and breathing rate are measured and recorded. The patient's legs are examined for areas of redness and signs of potential vascular problems.
The patient is asked to record his or her symptoms during the course of treatment to determine if and how symptoms improve over time. The patient should record the severity and duration of troublesome symptoms, the time the symptoms occurred, and any activities that may have triggered the symptoms. This patient record is reviewed before each treatment session.
PATIENT EDUCATION. The health care team will ensure that the patient understands the potential benefits and risks of the procedure. Informative and instructional handouts are usually provided to explain the procedure. Because the procedure requires multiple outpatient visits (generally 35 visits over a seven-week period), the patient must be able to meet the treatment schedule.
INFORMED CONSENT.Informed consent is an educational process between health care providers and patients. Before any procedure is performed, the patient is asked to sign a consent form. Before signing the form, the patient should understand the nature and purpose of the diagnostic procedure or treatment; the risks and benefits of the procedure; and alternatives, including the option of not proceeding with the test or treatment. During the discussion about the procedure, the health care providers are available to answer all of the pa tient's questions.
SMOKING CESSATION. Patients who will undergo any procedure to treat cardiovascular disease are encouraged to stop smoking and using any tobacco products before the procedure, and to make a commitment to be a nonsmoker after the procedure. There are several smoking cessation programs available in the community. The patient should ask a health care provider for more information if he or she needs help quitting smoking.
Discomfort
Patients report little or no discomfort during the procedure. Some people may feel tired after the first few treatments, but this loss of energy improves over time.
Lifestyle changes
To manage heart disease, the patient needs to make several lifestyle changes before and after the procedure, including:
Quitting smoking. Smoking causes damage to blood vessels, increases the patient's blood pressure and heart rate, and decreases the amount of oxygen available in the blood.
Managing weight. Maintaining a healthy weight, by watching portion sizes and exercising, is important. Being overweight increases the work of the heart.
Participating in an exercise program. The cardiac rehabilitation exercise program is usually tailored for the patient, who will be supervised by professionals.
Making dietary changes. Patients should eat a lot of fruits, vegetables, grains, and non-fat or low-fat dairy products, and reduce fats to less than 30% of all calories. Alcoholic beverages should be limited or avoided.
Taking medications as prescribed. Aspirin and other heart medications may be prescribed, and the patient may need to take these medications for life.
Following up with health care providers. The patient needs to visit the physician regularly to control risk factors.
Risks
EECP is a relatively safe and effective treatment, and few adverse side effects have been reported. The main adverse side effect is chafing (skin irritation from the compression of the cuffs). To reduce or prevent this side effect, patients are instructed to wear tight-fitting cycling pants or athletic tights. Leg pain is another adverse side effect.
Normal results
The benefits of EECP are comparable to the results of angioplasty and coronary artery bypass graft surgery: 80% of patients experience significant improvement after EECP treatment. The largest research study on EECP indicates that after receiving treatment, patients used less medication, had fewer angina attacks with less severe symptoms, and increased their capacity to exercise without experiencing symptoms. EECP improves the patient's sense of well-being and overall quality of life; and in some cases, prolongs the patient's life. Benefits five years after EECP treatment are comparable to surgical outcomes.
The effects of EECP treatment last from three to five years and sometimes longer.
EECP does not prevent coronary artery disease from recurring; therefore, lifestyle changes are strongly recommended and medications are prescribed to reduce the risk of recurrent disease.
Morbidity and mortality rates
Morbidity and mortality have not been reported with this procedure.
All patients with coronary artery disease should be prescribed medications to treat their condition. Such Antiplatelet medications as aspirin or clopidogrel (Plavix) are usually recommended. Other medications used to treat angina may include beta blockers, nitrates, and angiotensin-converting enzyme (ACE) inhibitors. Medications may also be prescribed to lower lipoprotein levels, since elevated lipoprotein levels have been associated with an increased risk of cardiovascular problems.
Treatment with vitamin E is not recommended because it does not lower the rate of cardiovascular events in people with coronary artery disease. Although such antioxidants as vitamin C, beta-carotene, and probucol show promising results, they are not recommended for routine use. Treatment with folic acid and vitamins B6 and B12 lowers homocysteine levels (reducing the risk for cardiovascular problems), but more studies are needed to determine if lowered homocysteine levels correlate with a reduced rate of cardiovascular problems in treated patients.
Coronary artery bypass graft surgery is a surgical procedure in which one or more blocked coronary arteries are bypassed by a blood vessel graft to restore normal blood flow to the heart. These grafts usually come from the patient's own arteries and veins located in the leg, arm, or chest.
BOOKS
McGoon, Michael D., ed., and Bernard J. Gersh. Mayo ClinicHeart Book: The Ultimate Guide to Heart Health, Second Edition. New York: William Morrow and Co., Inc., 2000.
Topol, Eric J. Cleveland Clinic Heart Book: The DefinitiveGuide for the Entire Family from the Nation's Leading Heart Center. New York: Hyperion, 2000.
Trout, Darrell, and Ellen Welch. "Enhanced External Counterpulsation (EECP)." In Surviving with Heart: Taking Charge of Your Heart Care. Golden, CO: Fulcrum Publishing, 2002.
PERIODICALS
Arora, R. R., et al. "The Multicenter Study of Enhanced External Counterpulsation (MUST-EECP): Effect of EECP on Exercise-Induced Myocardial Ischemia and Anginal Episodes." The Journal of the American College of Cardiology 33(7) 1999: 1833–1840.
Lawson, W. E., J. C. Hui, and P. F. Cohn. "Long-Term Prognosis of Patients with Angina Treated with Enhanced External Counterpulsation: Five-year Follow-Up Study." Clinical Cardiology 23(4) 2000: 254–258.
Soran, O. Z., et al. "Enhanced External Counterpulsation in the Management of Patients with Cardiovascular Disease." Clinical Cardiology 22 (1999): 173–178.
Urano, H., et al. "Enhanced External Counterpulsation Improves Exercise Tolerance, Reduces Exercise-Induced Myocardial Ischemia and Improves Left Ventricular Diastolic Filling in Patients with Coronary Artery Disease." Journal of the American College of Cardiology 37, no. 1 (2001): 93–99.
ORGANIZATIONS
American College of Cardiology. Heart House. 9111 Old Georgetown Rd., Bethesda, MD 20814-1699. (800) 253-4636, ext. 694, or (301) 897-5400. <http://www.acc.org>.
American Heart Association. 7272 Greenville Ave., Dallas, TX 75231. (800) 242-8721 or (214) 373-6300. <http://www.americanheart.org>.
International EECP Therapists Association. P.O. Box 650005, Vero Beach, FL 32965-0005. (800) 376-3321, ext. 140. <http://www.ietaonline.com>.
National Heart, Lung and Blood Institute. National Institutes of Health. Building 1. 1 Center Dr., Bethesda, MD 20892. E-mail: <NHLBIinfo@rover.nhlbi.>. <http://www.nhlbi.nih.gov>.
Texas Heart Institute. Heart Information Service. P.O. Box 20345, Houston, TX 77225-0345. <http://www.tmc.edu/thi>.
OTHER
Cardiac Renewal Centers of America. (800) LONG-LIFE. <http://www.cardiacrenewal.com/>.
The Heart: An Online Exploration. Franklin Institute Science Museum. 222 North 20th Street, Philadelphia, PA, 19103. (215) 448-1200. <http://sln2.fi.edu/biosci/heart.html>.
Straight to the Heart: The EECP Treatment Option for Angina. Featuring Larry King. Spotlight Health, Inc., 2001. <http://www.eecp.com/tr/larry.htm>.
Angela M. Costello
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
EECP is performed by health care providers trained in the procedure. Interventional cardiologists, registered nurses, and other health care professionals may perform the procedure. Currently, EECP credentialing is being investigated by the International EECP Therapists Association (IETA). EECP is generally performed in an outpatient clinic or hospital.
QUESTIONS TO ASK THE DOCTOR
Why do you recommend this procedure?
Who will perform the procedure? How many years of experience does this doctor have? How many other EECP procedures has this doctor performed?
Can I take my medications the day of the procedure?
Can I eat or drink the day of the surgery? If not, how long before the surgery should I stop eating or drinking?
How long do the treatments last?
What should I do if I experience chest discomfort or other symptoms similar to those I felt before the procedure?
What types of symptoms should I report to my doctor?
Will I be able to perform my normal activities during the course of treatment?
When will I find out if the procedure was successful?
Will I have any pain or discomfort after the procedure?
What lifestyle changes (including diet, weight management, exercise, and activity changes) are recommended to improve my heart health?
How often do I need to see my doctor for follow-up visits after the procedure?
