MKSAP quiz: Coronary artery disease and type 2 diabetes

This month's quiz asks readers to evaluate a 64-year-old man with type 2 diabetes who has undergone coronary angiography after presenting with progressive exertional chest pain and shortness of breath.


A 64-year-old man is evaluated following coronary angiography. He initially presented several weeks ago for progressive exertional chest pain and shortness of breath. Nuclear stress testing demonstrated a large anterior stress defect and an ejection fraction of 33%. Coronary angiography was significant for 90% stenosis of the proximal left anterior descending artery, a chronically occluded right coronary artery, and 80% stenosis of the left circumflex artery. He currently has stable dyspnea and chest pressure with moderate activity. Medical history is significant for hyperlipidemia, hypertension, and type 2 diabetes mellitus. He is taking optimal doses of aspirin, lisinopril, carvedilol, amlodipine, atorvastatin, and metformin.

On physical examination, temperature is normal, blood pressure is 125/70 mm Hg, pulse rate is 60/min, and respiration rate is 18/min. The remainder of the physical examination is unremarkable.

Which of the following is the most appropriate next step in management?

A. Add ticagrelor
B. Coronary artery bypass graft surgery
C. Multivessel percutaneous coronary intervention
D. Percutaneous coronary intervention of the left anterior descending artery
E. Continue current medical therapy


MKSAP Answer and Critique

The correct answer is B. Coronary artery bypass graft surgery. This item is available to MKSAP 18 subscribers as item 71 in the Cardiovascular Medicine section. More information about MKSAP 18 is available online.

The most appropriate treatment is coronary artery bypass graft (CABG) surgery. This patient with three-vessel coronary artery disease (CAD), left ventricular dysfunction, and type 2 diabetes mellitus has symptoms of heart failure and angina despite optimal medical therapy. In patients with multivessel coronary artery disease, revascularization with CABG results in decreased recurrence of angina, lower rates of myocardial infarction, and fewer repeat revascularization procedures compared with percutaneous coronary intervention (PCI). Unlike PCI, CABG surgery improves survival in patients with left main or three-vessel CAD and is recommended to reduce mortality in these high-risk patients. CABG surgery has also been shown to improve symptoms and survival in patients with ischemic cardiomyopathy. Long-term follow-up of the STICH trial demonstrated a survival advantage with CABG surgery compared with medical therapy alone among patients with multivessel CAD and severe left ventricular dysfunction. Additionally, CABG surgery has consistently been shown to be the superior revascularization strategy in patients with diabetes and multivessel disease who require revascularization.

Ticagrelor is indicated as a component of dual antiplatelet therapy following acute coronary syndrome, regardless of whether percutaneous coronary intervention is performed. However, there is no clear role for the addition of ticagrelor in this patient.

This patient has two separate indications for CABG surgery: 1) multivessel disease and reduced ejection fraction and 2) diabetes with concomitant multivessel disease. Patients with these indications who undergo CABG have improved survival compared with patients who receive only optimal medical therapy. Therefore, continuing this patient's medical therapy without further intervention would be inappropriate.

Key Point

  • Coronary artery bypass graft surgery is recommended to improve survival in patients with multivessel coronary artery disease and left ventricular dysfunction and patients with diabetes mellitus and multivessel disease.