In contrast, MACE occurred more often after DES implantation than after CABG in those with an intermediate or high SYN- TAX score.14 At 3 years of follow-up, the mortality rate was greater in subjects with 3-vessel CAD treated with PCI than in those treated with CABG (6.2% versus 2.9%). The differences in MACE between those treated with PCI or CABG increased with an increasing SYNTAX score (Figure 1).46 Although the utility of using a SYNTAX score in everyday clinical practice remains uncertain, it seems reasonable to conclude from SYNTAX and other data that outcomes of patients undergoing PCI or CABG in those with relatively uncomplicated and lesser degrees of CAD are comparable, whereas in those with complex and diffuse CAD, CABG appears to be preferable.46 See Online Data Supplements 5 and 6 for additional data comparing CABG with DES. 2.7. Left Main CAD 2.7.1. CABG or PCI Versus Medical Therapy for Left Main CAD CABG confers a survival benefit over medical therapy in patients with left main CAD. Subgroup analyses from RCTs performed 3 decades ago included 91 patients with left main CAD in the Veterans Administration Cooperative Study.28 A meta-analysis of these trials demonstrated a 66% reduction in relative risk in mortality with CABG, with the benefit extending to 10 years.30 The CASS Registry24 contained data Figure 1. Cumulative incidence of MACE in patients with 3-vessel CAD based on SYNTAX score at 3-year follow-up in the SYNTAX trial treated with either CABG or PCI. CABG indicates coronary artery bypass graft; CAD, coronary artery disease; MACE, major adverse cardiovascular event; PCI, percutaneous coronary intervention; and SYNTAX, Synergy between Percutaneous Coronary Inter- vention with TAXUS and Cardiac Surgery. 