Superiority of moderate control of hyperglycemia to tight control in patients undergoing coronary artery bypass grafting

Abstract

Objective Although consensus in cardiac surgery supports tight control of perioperative hyperglycemia (glucose <120 mg/dL), recent studies in critical care suggest moderate glycemic control may be superior. We sought to determine whether tight control or moderate glycemic control is optimal after coronary artery bypass grafting. Methods From 1995 to 2008, a total of 4658 patients with known diabetes or perioperative hyperglycemia (preoperative glycosylated hemoglobin ≥8 or postoperative serum glucose >126 mg/dL) underwent isolated coronary artery bypass grafting at our institution. Patients were stratified into 3 postoperative glycemic groups: tight (≤126 mg/dL), moderate (127–179 mg/dL), and liberal (≥180 mg/dL). Preoperative risk factors, glycemic management, and postoperative outcomes were analyzed. Results Operative mortality was 2.5%(119/4658); major complication rate was 12.5%(581/4658). Relative to moderate group, more patients in tight group had preoperative renal failure (tight 16.4%, 22/134, moderate 8.3%, 232/2785, P = .001) and underwent emergent operations (tight 5.2%, 7/134, moderate 1.9%, 52/2785, P = .007); however, Society of Thoracic Surgeons predicted mortality risk was lower in tight group (P < .001). Moderate group had lowest mortality (tight 2.9%, 4/134, moderate 2.0%, 56/2785, liberal 3.4%, 59/1739, P = .02) and incidence of major complications (tight 19.4%, 26/134, moderate 11.1%, 308/2785, liberate 14.2%, 247/1739, P < .001). Risk-adjusted major complication incidence (adjusted odds ratio 0.7, 95% confidence interval 0.58–0.87) and mortality (adjusted odds ratio 0.6, 95% confidence interval 0.37–0.83) were lower with moderate glucose control than with tight or liberal management. Conclusions Moderate glycemic control was superior to tight glycemic control, with decreased mortality and major complications, and may be ideal for patients undergoing isolated coronary artery bypass grafting.

Perioperative catabolism

“…80 In contrast, more recent studies in cardiac patients failed to show any benefit but reported an increased incidence of hypoglycemia. [81][82][83][84] All these studies were small and some were retrospective.…”

ESC Guidelines on diabetes, pre-diabetes, and cardiovascular diseases developed in collaboration with the EASD – Summary

“…Observational data in CABG suggest that continuous intravenous insulin infusion achieving moderately tight glycaemic control (6.6-9.9 mmol/L or 120-180 mg/dL) is independently associated with lower mortality and major complications, than has been observed after tighter (<6.6 mmol/L or <120 mg/dL) or more lenient (>9.9 mmol/L or >180 mg/dL) glycaemic control. 264 In the BARI 2D trial, outcomes were similar in patients receiving insulin sensitization vs. insulin provision to control blood glucose. In the CABG stratum, insulin use was associated with more cardiovascular events than insulin-sensitization.…”

Ambulatory anesthesia: optimal perioperative management of the diabetic patient

“…Whereas several early interventional studies have shown a beneficial effect of tight intraoperative glycemic control, 33,72,73 most recent studies do not support these findings. [74][75][76][77] In a recent meta-analysis of six studies, 75 a moderate glycemic target (between 5.6 and 8.3 mmol L −1 ) was found to be most beneficial in terms of postoperative complications and mortality as lower targets (less than 5.6 mmol L −1 ) did not lead to improved outcomes. Moreover, hyperglycemia in patients with DM might be less detrimental than hyperglycemia in patients without DM.…”