Background There are scant outcomes data in patients with type 2 diabetes and stable coronary artery disease (CAD) stratified by detailed angiographic burden of CAD or left ventricular ejection fraction (LVEF). Objectives This study determined the effect of optimal medical therapy (OMT), with or without percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG), on long-term outcomes with respect to LVEF and number of diseased vessels, including proximal left anterior descending artery involvement. Methods A patient-level pooled analysis was undertaken in 3 federally-funded trials. The primary endpoint was the composite of death, myocardial infarction (MI), or stroke, adjusted for trial and randomization strategy. Results Among 5,034 subjects, 15% had LVEF <50%, 77% had multivessel CAD, and 28% had proximal left anterior descending artery involvement. During a median 4.5-year follow-up, CABG + OMT was superior to PCI + OMT for the primary endpoint (hazard ratio [HR]: 0.71; 95% confidence interval [CI]: 0.59 to 0.85; p = 0.0002), death (HR: 0.76; 95% CI: 0.60 to 0.96; p = 0.024), and MI (HR: 0.50; 95% CI: 0.38 to 0.67; p = 0.0001), but not stroke (HR: 1.54; 95% CI: 0.96 to 2.48; p = 0.074). CABG + OMT was also superior to OMT alone for prevention of the primary endpoint (HR: 0.79; 95% CI: 0.64 to 0.97; p = 0.022) and MI (HR: 0.55; 95% CI: 0.41 to 0.74; p = 0.0001), and was superior to PCI + OMT for the primary endpoint in patients with 3-vessel CAD (HR: 0.72; 95% CI: 0.58 to 0.89; p = 0.002) and normal LVEF (HR: 0.71; 95% CI: 0.58 to 0.87; p = 0.0012). There were no significant differences in OMT versus PCI + OMT. Conclusions CABG + OMT reduced the primary endpoint during long-term follow-up in patients with type 2 diabetes and stable CAD, supporting this as the preferred management strategy.