Enhanced external counterpulsation--a therapeutic option for patients with chronic cardiovascular problems

Abstract

EECP is a non-invasive outpatient treatment for cardiovascular disease refractory to medical and/or surgical therapy. It has been cleared by the Food and Drug Administration for the treatment of a variety of cardiac conditions including congestive heart failure and chronic stable angina. A course of therapy consists of 35 one-hour treatments given once or twice daily. Augmented diastolic pressure and retrograde flow improve myocardial perfusion, while systolic unloading reduces cardiac workload and oxygen requirements. As a result of this treatment, most patients experience increased time to onset of ischemia, increased exercise tolerance, a reduction in the number and severity of anginal episodes, and improved quality of life. Evidence has been presented that this effect lasts well beyond the immediate post-treatment period with some patients symptom-free for several years. Because patients principally seek medical care to live longer or feel better, heart programs need to offer their patients the latest medical advances which have the potential of improving patient survival and health status (symptoms, functioning, and quality of life). Heart programs face a challenging economic future. Increased competition makes it necessary to implement strategies for market differentiation. Those programs most attuned to what their patients define as critical to quality would be most likely to succeed. Over the past decade, there have been a growing number of patients with chronic angina who have exhausted the standard revascularization armamentarium. Because coronary artery bypass grafts occlude and restenosis occurs at angioplasty sites, many patients no longer have suitable coronary anatomy for additional procedures. Also, as the population ages, the proportion of patients with diffuse coronary disease, congestive heart failure, significant co-morbid illness, and poor functional status increases. The incapacitating effects of angina on patients' abilities to work, maintain regular social interactions, and participate in the usual activities of daily living are well described. In spite of the ongoing successes of catheter-based revascularization techniques, the population of patients with intractable angina continues to grow; and ironically, advancements in medical therapy have resulted in an increasing number of patients who are living with severe left ventricular dysfunction and congestive heart failure. Recent studies have estimated that approximately 5-15% of patients undergoing coronary angiography may be considered to have advanced coronary artery disease. Considering that 1,713,000 cardiac catheterizations were performed in 1996 in the United States, approximately 100,000-250,000 patients per year may be eligible for newer treatments for coronary artery disease. More recent statistics in the AHA Heart and Stroke Update report that in 2001, nearly one million patients had coronary artery bypass graft surgery or percutaneous coronary intervention, (Figure 1). Of these, 125,650 patients experienced persistent angina.