Diabetic control and coronary artery bypass: effect on short-term outcomes.

AIM: To evaluate the effect of preoperative glycemic control on hospital morbidity and mortality in diabetic patients undergoing primary coronary artery bypass grafting.
METHODS: Data of 3857 patients undergoing primary coronary artery bypass grafting was prospectively collected and retrospectively analyzed. There were 1109 (29%) diabetic patients, of whom 712 (64%) had hemoglobin A1c levels recorded. They were categorized by diabetic treatment: diet (179), oral hypoglycemic agent, (718) or insulin (212); and by diabetic control: hemoglobin A1c < 7 (265) or ≥7 (447). Nondiabetic patients (2,748) were used as controls.
RESULTS: The preoperative risk factors of hypertension (p < 0.001), hyperlipidemia (p < 0.001), renal failure (p < 0.04), peripheral vascular disease (p < 0.001), and chronic obstructive pulmonary disease (p < 0.04) were significantly more prevalent in diabetic patients. Major complications were not significantly different between the diabetic and control groups (p = 0.33), but minor complications were less frequent in diabetic patients (p = 0.03). Major and minor complications were not significantly different among the treatment subgroups of diabetic patients (p = 0.74 and p = 0.48) or in those with hemoglobin A1c < 7 and ≥7 (p = 0.23, p = 0.41).
CONCLUSIONS: Short-term outcomes were not affected by the degree of preoperative glycemic control or type of treatment used in diabetic patients undergoing primary coronary artery bypass grafting. A plausible explanation is strict protocol-driven glycemic control in the perioperative period.