Patients with refractory angina who are not candidates for myocardial revascularization have limited options to relieve ischemia. Failed maximal medical therapy may lead to heart transplantation, but this is a rarely used option. Some success with enhanced external counterpulsation (EECP) has been reported (27). EECP increases diastolic aortic and coronary perfusion pressure and reduces afterload, augmenting cardiac output. Multicenter study results suggest that EECP can safely improve exercise treadmill parameters as well as reduce pain and medication use in patients with chronic stable angina (28). Long-term follow-up studies of patients with severe left ventricular dysfunction treated with EECP for angina pectoris have demonstrated improved event-free survival rates. Soran et al (29) examined 363 patients who had refractory angina and a left ventricular ejection fraction ≤35%. After completion of EECP therapy, severity of angina was significantly decreased, with 72% improved from severe angina to no or mild angina. At 2 years, this decrease in angina was maintained in 55% of patients, and major cardiovascular event rates were low.

Transmyocardial laser revascularization has produced variable results in patients with end-stage CAD and refractory angina. Although both surgical and percutaneous transmyocardial laser revascularization have been associated with reduced symptoms and improved exercise tolerance, the mechanism of action is incompletely understood. Objective cardiac perfusion measurements are inconclusive, and randomized trials have failed to demonstrate an increase in survival. Two sham-controlled, randomized clinical trials of percutaneous myocardial laser revascularization did not show any benefit from the procedure; rather, these studies highlighted the important role of the placebo effect in the response to the intervention (30).

27. Shea ML, Conti CR, Arora RR. An update on enhanced external counterpulsation. Clin Cardiol. 2005;28:115-8. [PMID: 15813616]
28. Arora RR, Chou TM, Jain D, Fleishman B, Crawford L, McKiernan T, et al. The multicenter study of enhanced external counterpulsation (MUST-EECP): effect of EECP on exercise-induced myocardial ischemia and anginal episodes. J Am Coll Cardiol. 1999;33:1833-40. [PMID: 10362181]
29. Soran O, Kennard ED, Kfoury AG, Kelsey SF. Two-Year Clinical Outcomes After Enhanced External Counterpulsation (EECP) Therapy in Patients With Refractory Angina Pectoris and Left Ventricular Dysfunction (Report from the International EECP Patient Registry). Am J Cardiol. 2006;97:17-20. [PMID: 16377276]
30. Saririan M, Eisenberg MJ. Myocardial laser revascularization for the treatment of end-stage coronary artery disease. J Am Coll Cardiol. 2003;41:173-83. [PMID: 12535804]

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