Coronary Artery Revascularization in Patients With Diabetes Mellitus

Diabetes mellitus (DM) is caused by inadequate insulin secretion or an inability to respond appropriately to secreted insulin, which leads to chronic hyperglycemia. An estimated 171 million people worldwide have DM, and the prevalence of DM will more than double over the next 2 decades.1 Patients with DM have a 2- to 4-fold increased risk of coronary artery disease (CAD) over nondiabetic patients,2 and 75% of diabetic patients die as a result of a cardiovascular cause.3 Diabetic patients commonly undergo percutaneous revascularization procedures; 25% to 30% of all percutaneous coronary interventions (PCIs) are performed in patients with DM.4 A diagnosis of DM is also considered equivalent to having CAD because diabetic patients without a history of CAD have a 5-year cardiovascular mortality that is similar to that of nondiabetic patients who have a history of myocardial infarction (MI).5 According to current American College of Cardiology/American Heart Association guidelines, patients with DM are therefore treated as having a CAD equivalent.6,7 Previous review articles have summarized specific medical therapies for patients with DM.8,9 This review focuses on mechanisms of accelerated atherosclerosis, percutaneous and surgical revascularization strategies, and outcomes among patients with DM and CAD.Diabetic patients have increased rates, extent, and complexity of atherosclerotic CAD.8 After coronary revascularization, diabetics have an increased risk of target vessel failure (TVF) and need for repeat interventions.10 Altered inflammatory pathways stemming from the effects of hyperglycemia, insulin resistance, and altered free fatty acid metabolism predispose diabetic patients to endothelial dysfunction, thrombogenesis, monocyte activation, foam cell transformation, and altered smooth muscle cell migration.11–13 These mechanisms converge to create increased coronary artery plaque burden and more complex CAD (Figure 1A).Figure 1. Mechanisms of atherosclerosis and restenosis in diabetes mellitus. A , The combination …