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

BackgroundRed 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.MethodsProspective 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.ResultsThere 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.ConclusionThere 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.

背景：红细胞（red blood cell, RBC）输注与死亡率及并发症发生率升高存在关联。本分析旨在探讨接受择期开放经腹肾下腹主动脉瘤（abdominal aortic aneurysm, AAA）修复术、随访时长最长达15年的患者中，RBC输注与长期生存之间的关联。
方法：本研究为前瞻性队列研究，数据来源于2000年至2015年的丹麦血管登记系统（Danish Vascular Registry）。主要终点为全因死亡率，次要终点为院内并发症。根据输注的RBC单位数，将接受输血的患者分为亚组：1单位、2~3单位、4~5单位及＞5单位。采用多校正Cox回归分析，比较未输血患者与各输血亚组患者的主要及次要终点事件发生情况。
结果：本研究共纳入3876例患者，平均生存时长为9.1年。其中801例患者未接受红细胞输注。所有患者的总体30天死亡率为3.1%（121例），输血患者的30天死亡率为3.6%（112例）。按输血亚组划分，各亚组的30天死亡率分别为：未输血组1.1%（9例）、输注1单位RBC组1.2%（4例）、输注2~3单位RBC组2.2%（26例）、输注4~5单位RBC组1.9%（14例）以及输注＞5单位RBC组7.9%（68例）。与未输血患者相比，接受RBC输注患者的死亡风险比（hazard ratio, HR）为1.54，95%置信区间（95% confidence interval, 95% CI）为1.27~1.85。多校正模型显示，输注2~3单位RBC（HR=1.32，95%CI：1.07~1.62）、4~5单位RBC（HR=1.64，95%CI：1.32~2.03）以及＞5单位RBC（HR=1.96，95%CI：1.27~1.85）患者的死亡率均显著升高。
结论：择期AAA修复术中接受的RBC输注与短期及长期死亡率升高存在剂量依赖性关联。纳入患者中约25%存在术前贫血。本研究结果提示，应警惕可能存在的不必要且有害的RBC输注行为。