Diabetes is an independent predictor of many serious adverse events, including major adverse cardiac events (MACE). Spencer King, MD, St. Joseph's Heart and Vascular Institute and Emory University, Atlanta, Georgia, USA, reviewed several studies that evaluated revascularization in diabetic patients who have stable coronary artery disease (CAD). Dr. King discussed the issues that surround the choice of revascularization approach and whether it is needed at all for this group of patients.

The consensus from the studies that he reviewed indicates that interventional revascularization is gaining parity with surgery for those diabetic patients who fall into a high-risk group, but for stable patients without high-risk CAD and ischemia, revascularization can be deferred. Intensive medical interventions, as described in consensus guidelines [Smith SC Jr. Circulation 2006], are recommended for all diabetic patients with CAD.

The Emory Angioplasty versus Surgery Trial (EAST), which compared coronary angioplasty (percutaneous transluminal coronary angioplasty; PTCA) with coronary bypass surgery (coronary artery bypass graft; CABG) for patients with multivessel CAD, was the first study to suggest slightly (but not significantly) better survival outcomes for diabetic patients who received CABG compared with those who received angioplasty [King SB III et al. J Am Coll Cardiol 2000]. This trend was confirmed in the Bypass Angioplasty Revascularization Investigation (BARI I) trial, in which the survival rate for diabetic patients who received CABG was significantly (p=0.001) improved when compared with those who received PTCA [King SB III et al. N Engl J Med 1994]. This difference was not apparent when comparing similar procedures in nondiabetic patients.

The SYNTAX (Synergy between PCI with TAXUS and Cardiac Surgery) trial, which assessed the optimal revascularization strategy for patients with previously untreated three-vessel or left main CAD, reported no difference between the treatment approaches in medically treated diabetic patients with regard to all-cause death/cerebrovascular events/myocardial infarction (MI) at 12 months. However, a follow-up subgroup analysis suggested that at 1 year, the MACE and cerebrovascular event rates were higher in the angioplasty group, driven by an increase in repeat revascularization and MACE in patients with high SYNTAX scores [Banning AP et al. J AM Coll Cardiol 2010].

One year results from the Coronary Artery Revascularization in Diabetes (CARDIA) trial showed no apparent difference between CABG and PCI in terms of the composite endpoints of death, nonfatal MI, and non-fatal stroke; however, repeat revascularization was higher in the PCI group, which was expected [Kapur A. ESC 2008].

The question of which treatment approach is best, remains unanswered. The Future REvascularization Evaluation in patients with Diabetes mellitus: Optimal management of Multivessel disease (FREEDOM; NCT00086450) Trial is an ongoing study that is designed to provide the definitive answer to which treatment approach is best. This trial enrolled 1901 patients with diabetes and multivessel CAD who were eligible for PCI or CABG. Results are anticipated in 2012.

But is revascularization needed in all diabetic patients with CAD? The BARDI 2D trial compared prompt revascularization with delayed or no revascularization for patients with type 2 diabetes, CAD, and ischemia and no prior CABG or PCI within the past 12 months. The choice of PCI or CABG was selected, based on clinical or angiographic factors. Among high-risk patients (based on angiographic severity) who were selected for CABG, prompt revascularization reduced major cardiovascular (CV) events compared with delayed or no revascularization (p=0.01). Among lower-risk patients who were selected for PCI, the rates of major CV events were similar for the three options.

CV morbidity is a major burden in patients with type 2 diabetes. A target-driven, long-term, intensified intervention that is aimed at multiple risk factors in patients with type 2 diabetes and microalbuminuria reduces the risk of CV and microvascular events by about 50% [Gaede P et al. New Engl J Med 2003].