In the United States alone, more than 2.5 million patients with symptomatic coronary heart disease (CHD) are not amenable to percutaneous coronary intervention (angioplasty with stent deployment) or coronary artery bypass grafting (CABG) surgery because of unsuitable coronary anatomy, multiple previous revascularization attempts, age, additional comorbid conditions, or patient preference.
For these patients with medically refractory angina pectoris, enhanced external counter pulsation (EECP) is the only truly noninvasive and unique treatment for which a reduction of angina symptoms and nitrate usage, increased exercise tolerance, and an improvement in myocardial ischemia.
However, EECP has also been used in conditions other than coronary heart disease.
The cardiac syndrome X (CSX) is atypical chest pain, with electrocardiographic changes and documented ischemia despite normal coronary arteriograms (microvascular angina).
About 50% of women discharged with “normal coronaries” continue to experience atypical chest pain that are often unresponsive to anti-ischemic therapy.
It has been reported that EECP is beneficial in patients with medically refractory angina due to large epicardial vessel disease and those with microvascular coronary artery disease.
CSX is effectively treated with EECP therapy. There is a significant reduction after treatment in Canadian Cardiovascular Society angina class, inducible ischemia, with a low incidence of recurrent angina following EECP.
The efficacy of EECP in these patients supports improvement in endothelial function as a potential mechanism.
RESTLESS LEGS SYNDROME (RLS)
In this report, six patients with severe RLS (ages 55-80) underwent EECP treatment for angina or congestive heart failure as the main indication.
The average International RLS (IRLS) rating scale score for the 6 patients before treatment was 28.8, which indicates frequent and moderate to severe RLS.
After 35 days of EECP treatment the IRLS score was 6 (P<0.03), which indicates clinically insignificant. Long-term follow-up in 4 patients showed sustained improvement in two patients 1 year after EECP was completed. Therefore, EECP improves RLS symptoms significantly and could be considered as an adjunct treatment for patients with RLS. In some cases, the improvement lasts for months after the course of treatment. In this way EECP is unique and unlike pharmacotherapy which requires continuous daily treatment. These results suggest that decreases in vascular flow influence the peripheral or central nervous system leading to the sensory symptoms of RLS.
ERECTILE DYSFUNCTION (ED)
EECP increases arterial blood flow in peripheral and coronary artery disease. Several studies have demonstrated an increase in the flow of the internal iliac artery and in carotid and renal perfusion during EECP treatment.
In patients with erectile dysfunction (ED), who received EECP for 20 days, one-hour per day; EECP therapy showed a significant improvement of penile peak systolic flow as measured by Doppler sonography. No adverse effects were observed.
In conclusion, EECP is an effective treatment modality in patients with ED.
EECP therapy for 2 hours is an effective procedure to augment renal excretory function in healthy volunteers as well as in patients with liver cirrhosis. In healthy volunteers, the glomerular filtration rate (GFR) and renal plasma flow increased during EECP. In contrast, GFR and renal plasma flow remained the same in patients with cirrhosis, and their renal vascular resistance increased during EECP. Consequently, EECP improves diuresis, but does not influence the vasoconstrictive dysregulation of the kidneys in liver cirrhosis.
OCULAR ISCHEMIC DISEASE
Carotid artery stenosis is a leading cause of ischemic stroke and patients usually present with stroke symptoms of hemiplegia and homonymous hemianopia.
However, an increasing number of patients with carotid artery stenosis have ocular ischemic presentations such as retinal arterial obstruction, ischemic optic neuropathy, and optic atrophy.
In this study, a total of 65 patients with carotid artery stenosis were randomized to group A treated with EECP and medication, and group B treated with medication alone.
Significant improvement of visual acuity, visual fields and optical hemodynamics was observed in the patients of group A.
EECP increase the blood flow of carotid and vertebral arteries, as well as the ophthalmic artery. EECP simultaneously increases the perfusion pressure of posterior ciliary arteries and blood supply of the optic nerve, decreases ischemia and the poor supply of oxygen in the optic nerve.
As a result, EECP gradually improves the visual function, and significantly improves the visual acuity and field of vision of patients.
There was significant improvement in the visual acuity, visual fields and optical hemodynamics of the patients in group A, where statistically significant differences were observed between groups A and B.
The present study has shown that EECP is safe and effective in the treatment of carotid artery stenosis and reduce the incidence of ophthalmic and cerebral complications.
The symptoms of ocular ischemic diseases and the vision of the patient could be effectively improved by EECP, which has no evident complications.
Even low-vision patients with long-term optic atrophy may benefit from EECP.
In subjects with abnormal glucose tolerance (AGT), standard EECP therapy of 35, 1-hour sessions, has a beneficial effect on peripheral arterial function (increased normalized brachial artery and popliteal artery flow-mediated dilation plus NO); and glucose tolerance (FPG).
In patients with type II diabetes mellitus, EECP standard treatment improves fasting glucose (FPG) and glucose tolerance, as measured by oral glucose tolerance test (OGTT). The mechanism responsible for this improvement may reside in utilization of Nitric Oxide (NO)-mediated glucose uptake pathway to compensate for impaired insulin-mediated glucose uptake manifested in T2DM.
In patients with a clinical diagnosis of type II diabetes mellitus, EECP has shown to improve glycemic parameters of fasting plasma glucose (FPG), postprandial glucose (PPG120), and glycosylated hemoglobin (HbA1c) that persist for up to three months following EECP treatment of 35, 1-hour sessions.
EECP is a noninvasive, non-pharmacologic intervention proven to increase nitric oxide bioavailability in patients with CAD.
In patients with a clinical diagnosis of T2DM, standard EECP therapy of 35 sessions, significantly decreases advanced glycation end products (AGEs) and receptors for AGEs (RAGEs) concentrations; inflammation (proinflammatory cytokine concentrations); and oxidative stress that persist for up to six months following treatment.