Glycemic variability, but not HbA 1c , is associated with high SYNTAX scores at the acute phase of myocardial infarction (AMI) in diabetic patients treated with insulin infusion

Background In acute myocardial infarction (AMI), high blood glucose at admission is associated with mortality, but randomized trials using intravenous insulin infusions (IVII) have presented conflicting results. In diabetic patients with CAD, glucose variability (GV) is a prognostic factor through progression of non-culprit lesions, coronary plaque vulnerability, and left ventricular remodeling. We aim to identify factors associated with high GV among diabetic patients admitted for AMI and treated with IVII. Methods All consecutive diabetic patients admitted to our University Hospital for AMI between January 2014 and March 2016 and who received IVII were included. Mean amplitude of glycemic excursions (MAGE) was calculated within 2 days after admission, as an index of GV. Results Among the 1305 AMI admitted, 196 patients were included. Mean age was 71.3 ± 12.1 years, 31% were women, with MAGE at 0.72 ± 0.41. When compared with lower MAGE tertiles, patients from the last tertile were more often women, chronically treated with insulin, with history of renal failure, higher glycemia at admission, HbA 1c levels, SYNTAX and GRACE scores, and lower systolic (SBP) and diastolic (DBP) blood pressures. After multivariate analysis, female (OR (95% CI): 5.67 (2.29–14.02)), HbA 1c (OR (95% CI): 1.77 (1.33–2.34)), SBP (OR (95% CI): 0.99 (0.97–1),) and SYNTAX score (OR (95% CI): 1.05 (1.01–1.08)) were associated with the highest tertile. Moreover, age (OR (95% CI): 1.05 (1.02–1.09)), history of stroke (OR (95% CI): 6.25 (1.65–23.5)) and the highest tertile of MAGE (OR (95% CI): 2.60 (1.24–5.41)) were associated with the highest tertile of SYNTAX score, whereas HbA 1c was not. Conclusion GV was mainly associated with diabetes-related factors, and was independently associated with a high SYNTAX score. Our findings suggest that assessment of blood GV could contribute to the identification of high-risk diabetics and become a therapeutic target in primary and secondary prevention.