Enhanced External Counterpulsation: Current Practices and Future Directions

Abstract

An estimated 6.4 million patients in the United State (U. S.) suffer from symptomatic coronary artery disease, and about 400,000 new cases develop each year. Despite optimal medical therapy and invasive procedures, such as angioplasty and cardiac bypass surgery, there are an estimated 300,000to 900,000 patients in the U.S. who have refractory anginapectoris (RAP). About 25,000 to 75,000 new cases of RAP are diagnosed each year. The technique of Enhanced External Counter pulsation (EECP) therapy consists of electrocardiogram-gated rapid, sequential compression of the lower extremities taking place during diastole, followed by simultaneous de compression during systole. These actions produce hemodynamic effects similar to those of an intra-aortic balloon pump, but unlike an intra-aortic balloon pump, EECP therapy also increases venous return. The Mulita-center Study of Enhanced External Counter Pulsation (MUST-EECP) is the first multi-center, prospective, randomized controlled trial that studied the effect of EECP on stable angina patients. The Research on Enhanced external Counter pulsation therapy in coronary artery disease (RECC) study found that EECP on top of optimal medical therapy improves myocardial ischemia and prognosis in patients with stable angina. In addition, EECP has been shown to induce collateral formation in the coronaries. Although EECP is a relatively safe and well-developed treatment, a safety assessment to rule out contraindications and lower treatment-related risks is necessary for high-risk and elderly patients before administration. The technique of counter pulsation, studied for almost one-half century now, is considered a safe, highly beneficial, low-cost, noninvasive treatment for these angina patients, and now for heart failure patients’ as well. Recent evidence suggests that enhanced external counter pulsation (EECP) therapy may improve symptoms and decrease long-term morbidity via more than 1 mechanism, including improvement in endothelial function, promotion of collateralization, enhancement of ventricular function, improvement in oxygen consumption (VO2), regression of atherosclerosis, and peripheral training effects similar to exercise.