The retrospective evaluation of the morbidity and mortality after coronary artery bypass grafting in patients with controlled and uncontrolled diabetes according to hba1c levels

Diabetes Mellitus impacts the quality and period of life seriously as a consequence of the macro and micro vascular complications caused. Coronary Artery Disease is the most important macro vascular complication caused and the most frequent reason of mortality among the diabetes patients. The ratio of morbidity and mortality of the patients who were performed coronary artery bypass graft is much higher than the ones without diabetes disease. It is targeted to present the preventability of the risks by comparing the morbidity and mortality ratios determined following to coronary artery bypass graft operations between the patients whose HbA1c level has (HbA1c <7) or has not (HbA1c ≥7) been kept under control and the patients who do not have any Diabetes Mellitus disease. 180 patients, who were performed a CABG, have been included in our survey from January 2007 till December 2009 at the University of Akdeniz, Faculty of Medicine, Department of Cardiovascular Surgery. The patients included in the survey were grouped according to the HbA1c levels; such as group 0, that is composed of 60 patients without diabetes whose HbA1c level is under 6% (the control group), group I, that is composed of 60 patients with diabetes whose HbA1c level is between 6 to 6,9% and group II, that is composed of 60 patients with diabetes whose HbA1c level is ≥ 7. Preoperative, perioperative and postoperative data were compared. The deaths occurred during the first 30 days were considered as mortality, all complications occurred during the same period were considered as morbidity. In control group no mortality has been detected, however in group I, with one patient the mortality ratio has been determined as 1, 7% and in group II with 5 57 patients the ratio has been 8,3%. The mortality ratio for the group with HbA1c ≥ 7 was statistically considered as significant. (p=0,02) It has been determined that the patients with HbA1c ≥ 7 had: dialysis need (25% p <0,01), atrial fibrillation (33% p=0,01), reoperation caused by bleeding (10% p=0,18), cerebrovascular incident (16,7% p=0,01), mechanical ventilator periods (19,5±21,6 p=0,06) and the period of stay at the hospital (average 9,91±5,35 day p=0,01) higher than the other groups. It has also been detected that the ratio of experiencing wounded tissue infection (53% p <0,01), mediastinitis (11% p=0,01) and urinary system infections (10% p=0,01) were as well higher. As a conclusion of our study, we consider that by obtaining good glycemic control during preoperative and postoperative periods thus, keeping the HbA1c levels under 7% even 6%, on patients who would be performed elective CABG, the morbidity and mortality ratios can considerably be decreased. Key words: Diabetes, Mellitus, HbA1c, Coronary Artery Bypass Grafting, Morbidity and Mortality