A Non-Invasive Alternative to
Something is definitely wrong. For weeks your complexion has grown steadily paler, you've fought constant bouts of weakness and dizziness and sometimes, for no apparent reason, your heart would suddenly race. Now, even simple actions like walking across the room brings a dull, nagging pressure in the middle of your chest accompanied by perspiration and shortness of breath.
A visit to your physician reveals a frightening diagnosis: coronary artery disease. Treatment begins immediately, but despite two cardiac catheterizations with balloon angioplasty and stenting and various prescription drugs, the chronic angina pain still won't go away. In fact, the symptoms are only getting worse. And now your doctor's latest recommendation is a terrifying one: open-heart bypass surgery.
But there is an alternative. It's a little known, non-invasive procedure that's been approved by the FDA and has been shown to alleviate angina miseries without the pain and complications associated with surgery. It's called External Counterpulsation.
What is EECP?
External Counterpulsation (EECP) is a nonpharmacologic, noninvasive, electromechanical technique approved for patients with angina pectoris- chest pain due to severe, symptomatic coronary artery disease-who have failed standard treatments and who cannot (or will not) undergo conventional procedures such as surgical bypass or angioplasty.4 EECP is facilitated through a pneumatic apparatus that creates a hydraulic pulse of blood flow inside the major arteries, using the vascular bed of the muscles as a pool of blood to pump. Its purpose is to boost cardiac output with no increase in cardiac work, improving cardiac efficiency and the general circulation.2
In an EECP session, the patient lies on a padded table. Three large inflatable cuffs-similar to blood pressure cuffs-are strapped around the calves, lower thighs and upper thighs. The patient's heart is monitored by an electrocardiograph machine, which, through a computer, regulates the inflation and deflation of the cuffs. During the part of the cardiac cycle when the heart is at rest (diastole), the cuffs are rapidly inflated in sequential order beginning with the cuffs at the calves and working upward. Just before systole (heart contraction), the cuffs are simultaneously deflated.5
The relaxation of the heart muscle is well-known to correlate electrocardiographically with the beginning of the "t-wave" representing electrical depolarization or recharging and it is the period when 85% of coronary blood flow takes place. This is the time in the cardiac cycle that is most vulnerable to obstruction by plaque that limits coronary blood flow. When the heart beats, electrically represented on the electrocardiographic trace as the "QRS complex", the EECP system relaxes, allowing the heart to pump easily into a "virtual space", with decreased vascular resistance to blood flow.
While the rest of the body receives oxygenated blood when the heart contracts, the heart muscle receives oxygen-rich blood through the coronary arteries when the heart is at rest. Therefore, the wave of pressure produced by the inflation of the cuffs when the heart is at rest increases blood flow to the heart. Deflation of the cuffs is timed so that when the heart contracts, the workload on the heart decreases as it pumps blood to other parts of the body.
When diastolic coronary flow is augmented on EECP, the arteries are presented with shearing, stretching and stress forces that are thought to release arterial growth factors including endothelin (EGF, a polypeptide) or nitric acid (from arginine and other amino acids, felt to be a vasodilator) and possibly to have enhanced responsiveness to growth hormone and other systemic mediators. Increased VEGF (vascular endothelial growth factor) and decreased BNP (beta-natriuretic peptide) have been shown in clinical studies.6 Another way of looking at it is to realize that the open coronary arteries will be exposed to full augmented pressure,7 while the closed or narrowed artery will have lower pressure. Fluids always try to "find" a path from the high-pressure area to the low-pressure zone.8
Patients usually experience little or no discomfort during the procedure. Most relax and read or watch television or listen to music; some sleep. Some people are fatigued after the initial treatments, but this tends to subside within a few sessions. Patients are given snug-fitting tights during the sessions to prevent chafing, one of the main adverse effects. Improvement is usually noticed after the 15th to 20th session.
EECP is most often administered as an outpatient procedure, with each session lasting one hour. A complete course of EECP typically involves 35 hours of treatment over four to seven weeks. Two sessions can be conducted in a day.9
The increasing availability of EECP adds a new dimension in the treatment of coronary artery disease. According to the American Heart Association, there are more than 7.2 million people who have a history of suffering from angina. Thousands have a condition so severe that they are forced to make significant changes in their lifestyle-impaired, disabled and unable to work-or worse, unable to do simple chores like walking up stairs, carrying groceries or washing their own hair. Even getting dressed can be exhausting. These people are often forced to remain inside their homes in relative seclusion.10,11 Angina can become unstable; a condition that implies heightened risk of heart attack or death. EECP may be useful in those emergency conditions as well3,12,13,14,15 but the usual goal is to improve symptoms and decrease the hazard of subsequent cardiac events.16
Like many cardiovascular procedures that have been in use for years,14,17,18 few formal adequate studies had been done to demonstrate and prove the benefits of EECP. In June 1999, however, the Journal of the American College of Cardiology published the blinded, sham-controlled Multicenter Study of Enhanced External Counterpulsation (MUST-EECP).19 The study and its accompanying editorial, monitored by authorities on heart disease, clearly demonstrated that EECP reduces angina and extends exercise time in patients with angina. Later that year, the Health Care Finance Agency (represented by Medicare) authorized payment for the procedure-the equivalent of an official blessing-followed by two significant reimbursement increases, including an increase in 2003 of 27 percent,5 bespeaking the healthcare administration's confidence in the method. In April of 2000, the FDA allowed all the manufacturers who could demonstrate that their machines were fundamentally the same to market them for angina treatment-a reversal of standard policy; again, a statement of confidence in this outpatient treatment.
Proof of EECP's effectiveness has come from all over the world, most notably Japan, where a study recently published in the Journal of the American College of Cardiology used a program of pre- and post- treatment thallium nuclear heart scanning to methodically examine a series of patients to demonstrate the correlation between clinical improvement and stress test results.20 The results showed that EECP is durable and persistent uniformly across demographic and co-morbidity (co-existing disease), with 85% to 90% showing significant improvement in symptoms.21,22,19,11
Consider what this means. Many of the EECP patients are cardiovascularly-speaking the worst of the worst, having failed standard, repeated invasive surgical or balloon therapies with limiting or disabling symptoms.23 For example, a "Class IV angina" patient can barely walk across a room without chest pain-and its attendant risk-and some even have chest pain at rest. EECP offers them a chance to be able to live better, pain free, resuming some quality of life with decreased anxiety over the next possible cardiac event.24,25
Some patients and cardiologists want to visualize EECP's results by repeating a thallium stress test and nuclear heart scan. An imaging study done in Tokyo, Japan20 showed consistent improvement in the patients who complete the course of therapy. Some doctors feel follow-up testing unnecessary; that the quality improvement has already been demonstrated to be due to increased myocardial perfusion in hundreds of patients.26 One other reason for testing, aside from peace of mind, is to know what the post-treatment scan looks like in case of other cardiac events later.27 On rare occasions, it may be necessary or desirable to have a second round of EECP treatment to attain maximal benefits.
Contentment and quality of life
In a three-year, follow-up study, the majority of patients who received EECP therapy remained free of angina and showed persistent improvements in their thallium scans.21 Patients and their families have also reported noticeably greater ability to engage in daily activity. A change in the pain status and susceptibility, comportment, energy level and quality of life may be seen as soon as the tenth hour of treatment, but physicians typically suggest to patients anticipate a change after the half way mark, or 17th to 25th session. Improvement persists and continues after the treatment cycle has finished, and a final post-EECP evaluation may be undertaken 6 to 12 weeks later. If the patient is able to continue getting useful exercise, in addition to dietary and preventive medications and supplementation, many patients report ongoing improvements and a whole new lease on life.
As previously discussed, EECP is a specialized noninvasive therapy for patients with severe anginal chest pain due to coronary artery disease who cannot or will not undergo traditional surgical or invasive procedures, or in whom standard methods have failed.4 Patients are excluded if they have aortic valve regurgitation or insufficiency; severe limiting peripheral vascular disease, uncontrolled congestive heart failure, severe uncontrolled hypertension, cannot understand the procedure or take full dose warfarin-type anticoagulation. While undergoing treatments for coronary artery disease, at most centers patients are required to remain under the care of their own cardiologist, and a cardiologist's written prescription is required.
Why isn't EECP widely available?
EECP machines are expensive. Even though the basic technology has been around for over 20 years in its present form, it still must meet exacting standards for precision delivery of pressures and timing. As such, all electromechanical equipment has special protective devices, monitoring systems, and computer interfaces, resulting in a base price tag of $100,000-$250,000 for a standard installation,3 not including space and any necessary construction costs. Then there are consumables, training, and staff, so a doctor's office has to be large enough and busy enough to support an adequate patient base to keep the machine in use.
Another reason for EECP's failure to dominate mainstream medical practice is that other, more invasive procedures have more panache. Angioplasty, surgical "open-heart" bypass, laser transmyocardial revascularization, high-tech invasive procedures, mega-centers and research methods are "sexy" meaning they are highly visible and dramatic and high-tech, so they attract attention and dollars and make a medical center look important. It's a marketing phenomenon. By the same token, it's also a matter of personal accountability-this is a quick fix society and the market responds to demand.
People are willing to subject themselves to the hazards of surgery instead of going for a gentler remedy. Why? Because that is how they've have been trained, that the quick and dramatic is better, even in the face of great risk of death or surgical catastrophe and the high probability of relapse. While some doctors are going back to the older approach of "let the body heal itself" using time-tested clinical acumen and intuition to make a diagnosis, in the U.S the predominant philosophy is still "more care" equals "real care."
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