DECIPHER-STICH is an ancillary study to the large-scale STICH trial, a multicenter international randomized study designed to define the role of coronary artery bypass grafting (CABG) and surgical ventricular restoration (SVR) in the treatment of HF in patients with CAD and LV dysfunction. In previous studies, DE has compared favorably to other methods for the detection of viable myocardium. The widespread availability of echocardiography and the possibility of simultaneously deriving information about structural abnormalities (e.g., thrombi), valve function, and intracardiac pressures in addition to the real-time assessment of regional and global systolic function make DE particularly useful for the comprehensive evaluation of CAD patients with LV dysfunction. Because patients in the STICH trial will also undergo radionuclide tests, the DECIPHER-STICH study will allow a comparison of the most commonly used techniques for assessment of myocardial viability. Patients recruited into the STICH trial will be invited to participate in the DECIPHER-STICH study and asked to sign a separate consent form prior to the randomized assignment of therapy. Forty centers from North America and Europe recruiting patients into the STICH trial have agreed to take part in the DECIPHER-STICH study. A total of 1,450 of the 2,800 patients enrolled into the STICH trial will undergo DE prior to treatment. DECIPHER-STICH will address the hypothesis of greater beneficial effect of coronary artery bypass surgery (CABG) over medical therapy alone on 3-year survival rate with 80% power to detect a 25%-to-12.5% reduction in all-cause mortality in patients with viable myocardium. In addition, the study will have >99% power to address three important secondary hypotheses. The results of this study will provide definitive information regarding the value of assessing myocardial viability with DE and significant clinical implications for the selection of patients with CAD, LV dysfunction, and HF who are most likely to benefit from surgical revascularization.