Outcome following coronary artery bypass grafting in patients with non-insulin diabetes mellitus

Background

Patients with diabetes mellitus have a worse hospital and long-term outcome after coronary artery bypass grafting (CABG) [1]. It has been shown that the non-insulin diabetes mellitus (NIDDM) group of patients on oral sulphonylureas have a higher mortality than those treated with insulin (IDDM) following myocardial infarction [2]. Oral sulphonylureas abolish ischaemic preconditioning, which is an important cardiac protective mechanism during the perioperative period of CABG [2]. Insulin resistance and hyper-glycaemia decrease arterial compliance, promote plaque growth and cause contractile dysfunction of the myocytes [3].

Objective

To analyse retrospectively outcome data in patients with NIDDM on oral sulphonylureas who underwent CABG.

Methods

From a total of 2537 patients who had CABG, outcome data was identified in 236 patients with NIDDM and in 130 patients with IDDM over a 2-year period (April 1999–March 2001). We compared the mortality, length of hospital stay, length of stay in the intensive care unit (ICU), reoperation rate, ICU re-admission rate and duration of operation with control patients, matched with respect to surgeon and risk score (EuroSCORE). We also compared the incidence of diabetes in Europe and North America with Papworth.

Results

There was no difference in length of hospital stay, length of ICU stay, reoperation rate, ICU re-admission rate and the duration of operation.

Conclusions

There is a higher mortality in the NIDDM group of patients compared with the IDDM and the non-diabetic group after CABG. Intensive insulin therapy in critically ill postoperative patients showed a reduction in hospital mortality and morbidity from renal failure, blood stream infections and polyneuropathy, and reduced red cell transfusion requirement [4]. Assessment of diabetic patients in the pre-assessment clinics, stopping sulphonylureas and converting to insulin preoperatively and to tight blood glucose control perioperatively, may help improve outcome in this group of patients.

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