Mortality, mode of death and risk indicators for death during 5 years after coronary artery bypass grafting among patients with and without a historyof diabetes mellitus

Objective To describe mortality, mode of death, risk indicators for death a nd symptoms of angina pectoris among survivors during 5 years after coronar y artery bypass grafting (CABG) among patients with and without a history o f diabetes mellitus. Methods All patients in western Sweden who underwent CABG without concomita nt valve surgery and who had no previous CABG between June 1988 and June 19 91 were entered prospectively in this study. After 5 years, information on deaths that had occurred was obtained for the analysis. Results In all, 1998 patients were included in the analysis; 242 (12%) had a history of diabetes. Among the non-diabetic patients, B-year mortality wa s 12.5%; the corresponding relative risk for diabetic patients was 2.1 (95% confidence interval 1.6 to 2.9). A history of diabetes was an independent risk indicator of death; there was no significant interaction between any o ther risk indicator and diabetes. Independent risk indicators for death amo ng diabetic patients were: current smoking, renal dysfunction and left vent ricular ejection fraction < 0.40. Compared with non-diabetic patients, thos e with diabetes more frequently died in hospital, died a cardiac death, or had death associated with the development of acute myocardial infarction an d with symptoms of congestive heart failure. Among survivors, diabetic pati ents tended to have more angina pectoris 5 years after CABG than did those without diabetes. Conclusion During a period of 5 years after CABG, diabetic patients had a m ortality twice that of non-diabetic patients. The increased risk included d eath in hospital, cardiac death and death associated with development of ac ute myocardial infarction and with symptoms of congestive heart failure. Co ron Artery Dis 11:339-346 (C) 2000 Lippincott Williams & Wilkins.