Red blood cell transfusion associated with increased morbidity and mortality in patients undergoing elective open abdominal aortic aneurysm repair

Background
Red blood cell (RBC) transfusions are associated with increased mortality and morbidity. The aim of this analysis was to examine the association between RBC transfusions and long-term survival for patients undergoing elective open infrarenal abdominal aortic aneurysm (AAA) repair with up to 15 years of follow-up.
Methods
Prospective cohort study using data from The Danish Vascular Registry from 2000–2015. Primary endpoint was all-cause mortality. Secondary endpoints were in-hospital complications. Transfused patients were divided into subgroups based on received RBC transfusions (1, 2–3, 4–5 or > 5). Using Cox regression multi-adjusted analysis, non-transfused patients were compared to transfused patients (1, 2–3, 4–5, >5 transfusions) for both primary and secondary endpoints.
Results
There were 3 876 patients included with a mean survival of 9.1 years. There were 801 patients who did not receive transfusions. Overall 30-day mortality was 3.1% (121 patients) and 3.6% (112) for all transfused patients. For the five subgroups 30-day mortality was: No transfusions 1.1% (9 patients), 1 RBC 1.2% (4 patients), 2–3 RBC 2.2% (26 patients), 4–5 RBC 1.9% (14 patients) and > 5 RBC 7.9% (68 patients). After receiving RBCs, the hazard ratio for death was 1.54 (95% CI 1.27–1.85) compared to non-transfused patients. There was a significant increase in mortality when receiving 2–3 RBC: HR 1.32 (95% CI 1.07–1.62), 4–5 RBC: 1.64 (1.32–2.03) and >5 RBC: 1.96 (1.27–1.85) in a multi-adjusted model.
Conclusion
There is a dose-dependent association between RBC transfusions received during elective AAA repair and an increase in short- and long-term mortality. Approximately 25% of included patients had preoperative anemia. These findings should raise awareness regarding potentially unnecessary and harmful RBC transfusions.