The incidence of blood transfusion after cardiac surgery ranges from less than 30% to over 90% and allogeneic red blood cell (RBC) transfusion has previously been reported to be associated with increased patient mortality. However, until today no study considered the competing influence of bleeding, anemia and transfusion on postoperative mortality.
Based on data from the prospective ACUITY trial (acute catheterization and urgent intervention triage strategy), which compared different antithrombotic regimens in 13,819 acute coronary syndrome patients undergoing PCI or CABG, the influence of major CABG-related bleeding complications, anemia and allogeneic transfusion on 1-year mortality was analyzed in 1491 patients who underwent CABG.
Postoperative, CABG-related major bleeding occurred in 52.9% of patients. The transfusion rates for red blood cells (RBC), fresh frozen plasma (FFP) and platelet concentrates (PTC) were 38.2%, 13.1% and 12.1%, respectively. 36.7% of transfused patients received > 4 RBC units. 1-year-mortality was 6.4%. Neither bleeding without transfusion, platelet or FFP transfusion or nadir hemoglobin concentration was associated with subsequent mortality. Only RBC transfusion > 4 units could be identified as an independent risk factor for increased mortality (early mortality, i.e. within 30 days after CABG, as well as late mortality, i.e. between 30 days and 1 year).
A substantial limitation of the present analysis is the absence of a predefined transfusion protocol. Moreover, no explanation is provided to explain the observed association between allogeneic RBC transfusion and mortality.
– Oliver Habler