Randomized Controlled Trial of Intensive Versus Conservative Glucose Control in Patients Undergoing Coronary Artery Bypass Graft Surgery: GLUCO-CABG Trial

Abstract

Objective: The optimal level of glycemic control needed to improve outcomes in cardiac surgery patients remains controversial.

Research design and methods: We randomized patients with diabetes (n = 152) and without diabetes (n = 150) with hyperglycemia to an intensive glucose target of 100-140 mg/dL (n = 151) or to a conservative target of 141-180 mg/dL (n = 151) after coronary artery bypass surgery (CABG) surgery. After the intensive care unit (ICU), patients received a single treatment regimen in the hospital and 90 days postdischarge. Primary outcome was differences in a composite of complications, including mortality, wound infection, pneumonia, bacteremia, respiratory failure, acute kidney injury, and major cardiovascular events.

Results: Mean glucose in the ICU was 132 ± 14 mg/dL (interquartile range [IQR] 124-139) in the intensive and 154 ± 17 mg/dL (IQR 142-164) in the conservative group (P < 0.001). There were no significant differences in the composite of complications between intensive and conservative groups (42 vs. 52%, P = 0.08). We observed heterogeneity in treatment effect according to diabetes status, with no differences in complications among patients with diabetes treated with intensive or conservative regimens (49 vs. 48%, P = 0.87), but a significant lower rate of complications in patients without diabetes treated with intensive compared with conservative treatment regimen (34 vs. 55%, P = 0.008).

Conclusions: Intensive insulin therapy to target glucose of 100 and 140 mg/dL in the ICU did not significantly reduce perioperative complications compared with target glucose of 141 and 180 mg/dL after CABG surgery. Subgroup analysis showed a lower number of complications in patients without diabetes, but not in patients with diabetes treated with the intensive regimen. Large prospective randomized studies are needed to confirm these findings.

© 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Figures

Figure 1

Mean glucose concentration and frequency of hypoglycemia in patients treated to intensive and conservative glucose targets. Cardiac surgery patients with hyperglycemia were randomized to an intensive glucose target (100–140 mg/dL) or to a conservative target (141–180 mg/dL). A: Mean glucose concentration on admission, during surgery (OR), randomization, ICU stay and CII, non-ICU hospital stay, and after hospital discharge. B: Frequency of hypoglycemia in the ICU and during CII, non-ICU hospital stay, and after hospital discharge. Open bars, intensive control; filled bars, conservative control. *P < 0.001; ≠P < 0.05.

Figure 2

Composite of perioperative complications in patients treated to intensive and conservative glucose targets. Cardiac surgery patients with hyperglycemia were randomized to intensive (100–140 mg/dL) or conservative (141–180 mg/dL) glucose targets. The primary outcome was differences in a composite of hospital complications, including mortality, wound infection, pneumonia, bacteremia, respiratory failure, acute kidney injury, and MACE. A: Composite of perioperative complications in all patients treated with intensive and conservative glucose targets. B: Composite of perioperative complications in patients with diabetes treated with intensive and conservative glucose targets. C: Composite of perioperative complications in patients without diabetes treated with intensive and conservative glucose targets. Open bars, intensive glucose target; filled bars, conservative glucose target. AKI, acute kidney injury.