Enhanced external counterpulsation (EECP) has been approved by the United States Food and Drug Administration (FDA) for management of refractory angina (Class IIb). EECP uses three sets of pneumatic cuffs that sequentially contract during diastole, increasing aortic diastolic pressure, augmenting coronary blood flow and central venous return. EECP improves anginal symptoms and exercise tolerance, and reduces nitroglycerin use in patients with chronic, stable angina. EECP has also been shown to be safe and beneficial in patients with symptomatic stable congestive heart failure. It has been postulated that cardiac benefits of EECP are mediated though vascular endothelial growth factor (VEGF) and nitric oxide mediated vasodilatation and angiogenesis. In June 2002, the FDA also approved EECP therapy for heart failure patients.
There is a high prevalence of symptomatic coronary artery disease (6.4 million patients) in the United States, with an annual incidence of about 400,000.1 In a subset of these patients: angina is not optimally controlled despite optimal medical management and coronary revascularization. This condition is termed refractory angina.2 The Scottish Intercollegiate Guidelines Network for management of refractory angina include: education, rehabilitation, cognitive behavioral therapy, spinal cord stimulation, transcutaneous electrical nerve stimulation, left stellate ganglion block, thoracoscopic sympathectomy, angiogenesis, and surgical transmyocardial revascularization, among others.3
In 1953, Kantrowitz demonstrated that coronary blood flow can be increased 20% to 40% by increasing diastolic blood pressure.4 Intra-aortic balloon pump (IABP) counterpulsation is an invasive method of increasing coronary blood flow, while enhanced external counterpulsation (EECP) is a non-invasive method. EECP therapy has been approved by the United States Food and Drug Administration (FDA) (Class IIb) for management of refractory angina and heart failure.