Patients with diabetes mellitus are at increased risk for coronary heart disease, atherosclerotic vascular disease and cardiac deaths compared with patients who do not have diabetes. This is true even in patients with diabetes who undergo coronary artery bypass grafting (CABG). The latter patients have an increase in the incidence of acute myocardial infarctions, graft occlusion and need for repeat CABG or angioplasty. Hoogwerf and colleagues studied the impact of lipid lowering agents and low-dose warfarin on cardiac disease, and clinical and angiographic outcomes, in patients with diabetes.

Patients who had undergone CABG procedures using saphenous vein grafts one to 11 years previously were recruited from multiple sites to participate in the study. The effects of lipid lowering and warfarin were studied in a double-blind randomized trial. Patients in the lipid-lowering segment were divided into two groups. One group was treated with aggressive lipid lowering with lovastatin and cholestyramine as necessary with the goal of maintaining a low-density lipoprotein (LDL) cholesterol level of 60 to 85 mg per dL (1.55 to 2.20 mmol per L) and the other group was treated with moderate lowering to an LDL cholesterol level of 130 to 140 mg per dL (3.36 to 3.62 mmol per L).Warfarin therapy was given to obtain a mean International Normalized Ratio of less than 2. Coronary angiography data were obtained before and at the conclusion of the study. A total of 1,351 patients enrolled in the study, including 116 who had type 2 diabetes mellitus (formerly called non–insulin-dependent diabetes). Comparisons between patients with and patients without diabetes were performed for clinical and angiographic outcomes.

The reduction in LDL was comparable among patients with and without diabetes in aggressive and moderate lipid-lowering groups. Aggressive lipid lowering had the same benefit in patients with diabetes as it did in patients without diabetes. This was true in clinical and angiographic outcomes measured during the study. The use of warfarin showed no benefit in any of the groups studied.

The authors conclude that patients with diabetes who have undergone CABG receive the same benefit from aggressive lipid lowering as patients without diabetes. This aggressive approach to lipid lowering improved clinical and angiographic outcomes. All patients with diabetes and a history of coronary artery disease should receive aggressive lipid-lowering therapy.