Incidence and prognostic impact of bleeding and transfusion after coronary surgery in low-risk patients

BACKGROUND: Excessive bleeding and blood transfusion are associated with adverse outcome after cardiac surgery, but their mechanistic effects are difficult to disentangle in patients with increased operative risk. This study aimed to evaluate the incidence and prognostic impact of bleeding and transfusion of blood products in low-risk patients undergoing coronary artery bypass grafting (CABG). STUDY DESIGN AND METHODS: Sixteen tertiary European centers of cardiac surgery contributed to the prospective European registry of CABG (E-CABG). The severity of bleeding was defined by the E-CABG bleeding severity classification and universal definition of perioperative bleeding (UDPB) classification. RESULTS: Of 1213 patients with EuroSCORE II of less than 2% (mean, 1.1 ± 0.4%), 18.5% suffered from mild bleeding (E-CABG bleeding Grade 1) and 3.4% experienced severe bleeding (E-CABG bleeding Grade 2-3). Similarly, 19.7% had UDPB Class 2 and 5.9% had UDPB Classes 3 and 4. Mild and severe bleeding defined by the E-CABG and UDPB classifications were associated with an increased risk of several adverse events as adjusted by multiple covariates. The risk of death, stroke, and acute kidney injury was particularly increased in patients with severe bleeding. CONCLUSION: Severe bleeding is rather uncommon in low-risk patients undergoing CABG, but it is associated with an increased risk of major adverse events. Prevention of excessive perioperative bleeding and patient blood management may improve the outcome of cardiac surgery also in low-risk patients.