Few data exist on the effect of trimetazidine on cardiovascular endpoints, mortality, or quality of life. The most frequently reported adverse events are gastrointestinal disorders, but the incidence is low. The agent is not available in the United States but is available in Europe and reportedly in .80 countries worldwide. 4.4.4. Alternative Therapies for Relief of Symptoms in Patients With Refractory Angina: Recommendations Class IIb 1. Enhanced external counterpulsation (EECP) may be considered for relief of refractory angina in patients with SIHD.910 (Level of Evidence: B) 2. Spinal cord stimulation may be considered for relief of refractory angina in patients with SIHD.911,912 (Level of Evidence: C) 3. Transmyocardial revascularization (TMR) may be considered for relief of refractory angina in patients with SIHD.913 915 (Level of Evidence: B) Class III: No Benefit 1. Acupuncture should not be used for the purpose of improving symptoms or reducing cardiovascular risk in patients with SIHD.916,917 (Level of Evidence: C) TMR has been used as either a percutaneous or a surgical procedure concomitant with CABG or as sole therapy in patients with angina refractory to medical therapy,913 915,918 although the mechanism by which it might be efficacious is unknown.919,920 Early studies of the percutaneous approach demonstrated no therapeutic benefit, and it was promptly abandoned.921 When used as sole therapy by a surgical approach, TMR is reserved for the patient with incapacitat- ing, medically refractory angina and no other feasible thera- Fihn et al Stable Ischemic Heart Disease: Full Text e411 peutic options. Proposed mechanisms of action include stim- ulation of microcirculation, creation of myocardial scarring, and denervation of ischemic myocardium.922 Various energy sources have been used, including carbon dioxide XeCl excimer and holmium:YAG lasers.923 925 There is no con- vincing evidence that one energy source is superior to the others. 