Individuals with type 2 diabetes who require insulin or oral anti-diabetic drugs have an increased early and long-term risk of dying or having a heart attack after heart bypass surgery, Swedish researchers report.

Dr. Torbjorn Ivert, of Karolinska University Hospital, Stockholm, and colleagues determined the risk of death or heart attack 10 years after bypass surgery in 6,727 patients who had the operation between 1980 to 1995.

Compared to nondiabetic patients, insulin-treated type 2 diabetics had a more than fourfold increased risk of dying early while those treated with oral anti-diabetic drugs had a twofold increased risk of early death.

The risk in diet-treated diabetic patients did not differ significantly from non-diabetics.

Moreover, survival at 10 years free of heart attack was 40 percent for patients with insulin-treated type 2 diabetes and 48 percent for those on oral drugs, compared with 59 percent for diabetic patients managed with diet restrictions only and 66 percent in patients without diabetes.

Compared to patients without diabetes, the relative risk of death or having a heart attack at 10 years was 80 percent higher in type 2 diabetic patients treated with insulin and 40 percent higher in type 2 diabetic patients treated with oral drugs.

“Our findings,” the team concludes, “support intense metabolic monitoring and attempt to reduce cardiovascular risk factors” in patients with diabetes, particularly those requiring insulin after coronary artery bypass surgery.

SOURCE: American Heart Journal, September 2006.