Type 2 diabetes mellitus, independent of insulin use, is associated with an increased risk of cardiac complications after vascular surgery

Previous reports on the prognostic value of diabetes mellitus for cardiac complications after vascular surgery show divergent results, especially in regards to the role of type 2 diabetes as a cardiac risk factor, which remains unclear. The aim of this study was to assess the impact of type 2 diabetes on 30-day cardiac complications after vascular surgery. Patients undergoing elective vascular surgery between 2002 and 2011 were included in this retrospective cohort study. Previous diagnosis of type 1 and 2 diabetes and use of oral glucose-lowering medications and insulin were recorded. Patients with type 1 diabetes were excluded from the analysis. The main outcome parameter was cardiac complications, a composite of cardiovascular death, non-fatal myocardial infarction, congestive heart failure, severe arrhythmia and asymptomatic troponin release within 30 days of surgery. In multivariate analysis, corrections were made for comorbidities, demographics, medication use and surgical risk. Of 1462 patients, 329 (22.5%) patients had type 2 diabetes. Cardiac complications occurred in 155 (13.7%) patients without diabetes and in 68 (20.7%) with type 2 diabetes. In multivariate analysis, type 2 diabetes was associated with a significantly increased risk of 30-day cardiac complications (odds ratio 1.80; 95% confidence interval 1.25 to 2.60). Results were similar for type 2 diabetes patients managed with (odds ratio 1.84; 95% confidence interval 1.01 to 3.37) and without (odds ratio 1.79; 95% confidence interval 1.19 to 2.70) insulin. Type 2 diabetes is an independent risk factor for cardiac complications after vascular surgery and should be treated as such in preoperative cardiac risk stratification.