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.