The appropriate management of this patient is coronary artery bypass grafting (CABG). He has type 2 diabetes mellitus and multivessel coronary artery disease (CAD) with moderate to severe symptoms despite optimal medical therapy. In multiple observational studies and randomized controlled trials, performing CABG compared with percutaneous coronary intervention (PCI) as the initial revascularization strategy in patients with a clear indication was associated with improved outcomes, including reduced rates of death, myocardial infarction (MI), and stroke. The FREEDOM trial evaluating management of multivessel CAD in patients with diabetes showed that the composite endpoint of death, MI, and stroke was significantly lower in patients treated with CABG versus PCI. This difference was driven by a statistically significant reduction in the occurrence of death and MI in CABG patients, although stroke rates were higher in the CABG group than the PCI group. CABG is recommended for patients who remain symptomatic despite optimal medical therapy and have specific angiographic findings (either left main disease or multivessel disease with involvement of the proximal left anterior descending artery), concomitant reduced systolic function, or diabetes mellitus.

β-Blockers are first-line antianginal agents because of their ability to reduce heart rate, myocardial contractility, and blood pressure, resulting in reduced myocardial oxygen demand. Calcium channel blockers are reasonable second-line therapy in patients who are intolerant of β-blockers or who have continued symptoms on β-blockers and nitrates. However, it would not be appropriate to switch to a calcium channel blocker, such as amlodipine, in this patient who currently tolerates an effective dose of a β-blocker.

Myocardial viability testing is performed with a radionuclide radiotracer that is taken up by viable myocardial tissue. Viability testing may demonstrate hypoperfused regions of the heart that might show functional improvement if revascularization is performed. However, information from a substudy of the Surgical Treatment of Ischemic Heart Failure (STICH) trial demonstrated no relationship between the results of viability imaging and the effectiveness of bypass surgery. Therefore, in this patient who remains symptomatic despite optimal medical therapy and is a reasonable surgical candidate, revascularization is indicated, and myocardial perfusion testing would not contribute significant information regarding medical decision making. Myocardial perfusion testing is typically limited to use in patients at high risk for revascularization surgery in whom assessing the degree of viable myocardium present may influence the risk-benefit ratio of surgical treatment.