CABG or PCI to improve symptoms should not be performed in patients who do not meet anatomic (>50% diameter left main or >70% non left main stenosis diameter) or physiological (eg, abnormal FFR) criteria for revascularization. (Level of Evidence: C) 5.4. CABG Versus Contemporaneous Medical Therapy In the 1970s and 1980s, 3 RCTs established the survival benefit of CABG compared with contemporaneous (although minimal by current standards) medical therapy without revas- cularization in certain subjects with stable angina: the Veter- ans Affairs Cooperative Study,1035 European Coronary Surgery Study,986 and CASS.1036 Subsequently, a 1994 meta- analysis of 7 studies that randomized a total of 2649 patients to medical therapy or CABG412 showed that CABG offered a survival advantage over medical therapy for patients with left main or 3-vessel CAD. The studies also established that CABG is more effective than medical therapy for relieving anginal symptoms. These studies have been replicated only once during the past decade. In MASS II (Medicine, Angio- plasty, or Surgery Study II), patients with multivessel CAD who were treated with CABG were less likely than those treated with medical therapy to have a subsequent MI, need additional revascularization, or experience cardiac death in the 10 years after randomization.1016 Surgical techniques and medical therapy have improved substantially during the intervening years. As a result, if CABG were to be compared with GDMT in RCTs today, the relative benefits for survival and angina relief observed several decades ago might no longer be observed. Con- versely, the concurrent administration of GDMT may sub- stantially improve long-term outcomes in patients treated with CABG in comparison with those receiving medical therapy alone. 