Long-term risk of stroke in patients with type 1 and type 2 diabetes following coronary artery bypass grafting

Abstract

Background-We performed a nationwide population-based cohort study to investigate the long-term risk of stroke after coronary artery bypass grafting in patients with type 1 and type 2 diabetes. Methods and Results-All patients who underwent primary coronary artery bypass grafting in Sweden from 2000 through 2011 were included from the SWEDEHEART register. We excluded patients with prior stroke, and patients who had a stroke or died within 30 days of surgery. The National Diabetes Register was used to identify patients with type 1 and type 2 diabetes. Incident stroke (ischemic and hemorrhagic), and all-cause mortality was obtained by record linkage with the National Patient Register and the Cause of Death register. We used multivariable Cox regression to estimate the risk of stroke in relation to type of diabetes. A total of 53 820 patients (type 1 diabetes [n=714], type 2 diabetes [n=10 054], no diabetes [n=43 052]) were included. During a mean follow-up of 7.4 years (398 337 person-years), in total, 8.0% (n=4296) of the patients had a stroke: 7.3% (n=52) in patients with type 1 diabetes, 9.1% (n=915) in patients with type 2 diabetes, and 7.7% (n=3329) in patients with no diabetes. The multivariable adjusted hazard ratio (95% CI) for all stroke was 1.59 (1.20-2.11) in type 1 diabetes, and 1.32 (1.23-1.43) in type 2 diabetes. Conclusions-The long-term risk for stroke after coronary artery bypass grafting was increased in patients with type 1 and type 2 diabetes, compared to patients with no diabetes.