Bleeding, transfusion and the risk of stroke after coronary surgery: A prospective cohort study of 2357 patients

Introduction This study was planned to investigate the impact of severe bleeding and blood transfusion on the development of stroke after coronary surgery. Methods This cohort study includes 2357 patients undergoing isolated CABG from the prospective European Coronary Artery Bypass Grafting (E-CABG) registry. Severity of bleeding was categorized according to the Universal Definition of Perioperative Bleeding (UDPB), E-CABG and PLATO definitions. Results Thirty patients (1.3%) suffered postoperative stroke. The amount of transfused red blood cell (RBC) (OR 1.10, 95%CI 1.03–1.18), preoperative use of unfractioned heparin (OR 4.49, 95%CI 1.91–10.60), emergency operation (OR 3.97, 95%CI 1.47–10.74), diseased ascending aorta (OR 4.62, 95%CI 1.37–15.65) and use of cardiopulmonary bypass (p = 0.043, OR 4.85, 95%CI 1.05–22.36) were independent predictors of postoperative stroke. Adjusted analysis showed that UDPB classes 3–4 (crude rate: 3.6% vs. 1.0%; adjusted OR 2.66, 95%CI 1.05–6.73), E-CABG bleeding grades 2–3 (crudes rate: 6.3% vs. 0.9%; adjusted OR 5.91, 95%CI 2.43–14.36), and PLATO life-threatening bleeding (crude rate: 2.5% vs. 0.6%, adjusted OR 3.70, 95%CI 1.59–8.64) were associated with an increased risk of stroke compared with no or moderate bleeding. Conclusions Bleeding and blood transfusion are associated with an increased risk of stroke after CABG, which is highest in patients with severe bleeding.