 The secondary outcome measures: are 1: Comparison of percent of post CABG time in hyperglycemia 1.8 gl and hypoglycemia 0.5 gl in the two randomization groups. 2: Comparison of clinical outcomes incidence during 30 days after CABG: death rate, cardiovascular events acute coronary syndromes, heart failure, arrhythmia stream infections, neurologic events. 3: Comparison of performance and accuracy between CGM with Glucoday and conventional capillary blood glucose monitoring in the setting of CABG and surgical ICU. 4: Comparison of duration of stay in ICU and in the surgical care unit. 5: Description of device and care tolerance by collection of all adverse events due to the device during the hospitalization 