Treatment options for refractory angina pectoris: enhanced external counterpulsation therapy

Refractory angina pectoris, defined as angina refractory to maximal medical therapy and standard coronary revascularization procedures, remains a significant health problem in the United States and the world. Despite a panoply of recent therapeutic advances, patients with refractory angina pectoris are not adequately treated; therefore, scientists have been investigating new technologies to help these patients. The technique of counterpulsation, studied for almost half a century, is considered a safe, highly beneficial, low-cost, noninvasive treatment for these angina patients and now also for those with heart failure. Recent evidence suggests that enhanced external counterpulsation (EECP) therapy may improve symptoms and decrease long-term morbidity via several mechanisms, including improvement in endothelial function, promotion of collateralization, enhancement of ventricular function, improvement in oxygen consumption (Vo(2)), regression of atherosclerosis, and peripheral "training effects" similar to exercise. Numerous clinical trials in the past two decades have shown EECP therapy to be safe and effective for patients with refractory angina, with a clinical response rate averaging 70% to 80%, which is sustained up to 5 years. This review summarizes the current evidence to support EECP's use in treating refractory angina pectoris.