A significant number of persons in the United States have diabetes. This number is expected to increase dramatically over the next few years. Diabetes is a risk factor for developing coronary artery disease. Despite recent advances in the treatment of coronary artery disease, significant numbers of patients with diabetes are hospitalized each year because of cardiovascular disease. In addition, coronary artery disease is responsible for 80 percent of deaths in persons with diabetes. One advance in the treatment of coronary artery disease is percutaneous coronary revascularization, but this treatment has a long-term limitation of restenosis. Patients with diabetes who receive percutaneous coronary interventions are at higher risk for restenosis compared with the general population. Corpus and colleagues evaluated the association between glycemic control and the incidence of target vessel revascularization in patients with diabetes who are undergoing elective percutaneous coronary intervention.

Patients who were scheduled to receive elective percutaneous coronary interventions at one center were eligible for the study. Patients with type 2 diabetes who were not under control with diet alone were enrolled; nondiabetic patients who had the procedure constituted the comparison group. Before the procedure, A1C, lipid panel, and fibrinogen were assessed. The procedure and post-procedure medications were based on standard protocols. Follow-up care was performed by telephone interview and hospital medical record review at six and 12 months after the procedure. Repeat catheterization was performed in patients who had recurrence of symptoms or objective evidence of ischemia. Optimal diabetic control was defined for this study as an A1C of 7 percent or less.

There were 179 consecutive patients with diabetes who participated in the study along with 60 randomly selected nondiabetic patients in the control group. Patients with diabetes who had optimal glycemic control had similar target revascularization rates compared with the control group. Patients with diabetes who had an A1C of more than 7 percent had a significantly higher rate of revascularization compared with patients with optimal glycemic control. In addition, optimal glycemic control was associated with a significantly lower rate of cardiac rehospitalization and recurrent angina at the 12-month follow-up. An A1C above 7 percent was a significant independent predictor for target vessel revascularization.

The authors conclude that patients with diabetes who are undergoing elective percutaneous coronary revascularization and have optimal glycemic control have better outcomes than those who do not have well-controlled diabetes. They note that aggressive treatment of diabetes with an A1C goal of 7 percent or less is beneficial in improving clinical outcomes after percutaneous coronary intervention.