DESPITE the increasing success of conventional medical therapeutic approaches and continued development and improvement of mechanical revascularisation approaches, a significant number of angina and coronary heart disease patients cannot be managed successfully. Also a substantial proportion of these patients do not achieve complete revascularisation even after successful angioplasty/bypass surgery and continue to experience exertional angina or ischemia despite medication. Apart from these factors, the traditional procedures — bypass surgery (CABG) and angioplasty (PTCA) — are expensive and involve a certain degree of risk in the form of iatrogenic morbidity and mortality.
Besides, unfortunately, treatment to clear blockages often results in cell regrowth that can obstruct vessels again. This condition, called re-stenosis, occurs after about 20 to 30 per cent of PTCA procedures. Repeat procedures are non uncommon and re-stenosis rates after repeat PTCA are as high as 50 per cent. With bypass surgery, repeat procedures are sometimes necessary. Six to 10 per cent of CABG procedures are now re-operations. However, re-operative mortality rates are two to three times of those of initial procedure and range from 2 to 3 per cent for second operations and up to 15 per cent for third and subsequent operations. Patients undergoing repeat procedures generally have more advanced coronary artery disease rendering the re-vascularisation process less effective.
EECP or Enhanced External Counter Pulsation is a new form of therapy that may relieve or eliminate angina by increasing blood flow to the heart. This therapy has been approved worldwide by the health authorities, including the Food and Drug Administration, USA, the NHS, England, and of course, China where it is widely practiced.
The patient lies down on a padded treatment table. The calves, thighs and hips are tied with cuffs which inflate in a sequential manner from calves upwards, thus "milking" and blood in the reverse direction precisely timed in milliseconds with a sophisticated computer, which increase the blood flow to the heart when it is relaxing and when the blood flow to the coronary arteries is at its peak. The increased blood flow pressure during this phase of the cardiac cycle causes dilatation of the coronary blood vessels, opens and expands the networks of the dormant small blood vessels. These channels can create natural bypasses around the clogged arteries boosting blood supply to the oxygen deprived areas of the heart. The permanent opening of these channels may account for the long lasting benefits of EECP therapy.
Typically, EECP is done as a series of 35 sessions, each lasting one hour. The patient is investigated through standard tests such as treadmill test (TMT), echocardiogram and stress thallium before and after the completion of the sessions to verify the improvement in the status of the patient. It is important to note here that for this treatment, coronary angiogram is not important as with it only the degree of blockage of the main coronary arteries and their branches can be assessed, and it is not suitable for visualising the minute vessels, arterioles and capillaries or for assessing the overall blood flow to a particular region of the heart which is actually more important.
Clinical studies over the past few years have shown that about 75 per cent of the patients treated with a single course of EECP experience a reduction in angina frequency and intensity, and are able to return to a more active lifestyle. The need for anti-anginal medication is reduced or eliminated. The ejection fraction (measure of heart function) shows improvement and so do the TMT and stress thallium scans.
Unlike procedures such as bypass surgery and balloon angioplasty, EECP treatment is administered in outpatient sessions, carries little or no risk and is relatively comfortable and inexpensive.
At present, this treatment is being offered to those patients who have chronic stable angina; who do not receive adequate relief from angina by taking nitrates; who do not qualify as candidates for invasive procedures; who have exhausted invasive treatments without lasting relief of symptoms; who are unwilling to undergo surgery or angioplasty or who want to explore alternatives to bypass surgery or angioplasty. Indeed, it is a viable alternative for those coronary heart disease patients who are not candidates for invasive or surgical interventions by the physician’s or their own choice.