Abstract 17182: Long-term Prognosis in Patients with Type 1 and Type 2 Diabetes Mellitus after Coronary Artery Bypass Grafting

Introduction: Patients with diabetes mellitus (DM) have an increased risk of adverse outcomes after coronary artery bypass grafting (CABG). Prior studies in patients with DM have reported prognosis in relation to treatment with insulin or not, and not in relation to type of DM. The prognosis after CABG in patients with type 1 or type 2 diabetes mellitus (DM1 or DM2) is not known. Methods: We included all patients who underwent primary isolated CABG in Sweden during 2003 through 2013 from the SWEDEHEART register, and the Swedish National Diabetes Register identified patients with DM1 or DM2. Cox proportional hazards regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI) for all-cause mortality in patients with DM1 or DM2 compared with no diabetes mellitus. Results: In total 36 035 patients underwent primary isolated CABG during the study period, of whom 628 (1.7%) had DM1, and 7544 (21%) had DM2. Patients with DM1 were younger (59 vs. 67 years), and had reduced kidney function (31% vs 24%), and peripheral vascular disease (21% vs 11%) more often than patients with DM2 or no diabetes. During a mean follow-up time of 5.8 (±3.1) years (210 228 person-years) in total 5980 (17%) died of whom 122 (19%) had DM1, and 1385 (18%) had DM2. The age-adjusted estimated survival is shown in Figure 1. After multivariable adjustment for age, sex, chronic obstructive pulmonary disease, peripheral vascular disease, renal function, and left ventricular ejection fraction HRs with 95% CI for death in patients with DM1, and DM2, compared with patients without diabetes were 2.17 (1.79 to 2.62), and 1.17 (1.10 to 1.25), respectively. Conclusions: Patients with DM1 had a more than doubled long-term risk of death compared with patients without diabetes after CABG. The long-term risk of death in patients with DM2 was only slightly increased. Figure 1. Cox age-adjusted survival in 36 035 patients who underwent primary isolated CABG in relation to Type 1, Type 2 or no diabetes mellitus.