Liberal or Restrictive Postoperative Transfusion in Patients at High Cardiac Risk

Importance: Postoperative red blood cell transfusion guidelines recommend transfusion for hemoglobin levels less than 7 g/dL. However, the safety of this strategy in patients at high risk of cardiac events undergoing major operations remains unclear. Objective: To evaluate the risk of death or major ischemic events within 90 days after a liberal transfusion strategy compared with a restrictive transfusion strategy in patients at high risk of cardiac events who had undergone major vascular or general surgery operations and developed postoperative anemia. Design, Setting, and Participants: This parallel, single-blind, randomized clinical superiority trial included 1428 veterans (≥18 y) at high cardiac risk undergoing major vascular or general surgery operations. Participants were enrolled from February 2018 to March 2023 across 16 Veterans Affairs Medical Centers in the US. Interventions: Seven hundred fourteen participants with postoperative hemoglobin less than 10 g/dL were randomized to a liberal strategy (transfusion trigger at hemoglobin level <10 g/dL) and 714 to a restrictive strategy (transfusion trigger at hemoglobin <7 g/dL). Main Outcomes and Measures: The primary end point was a composite of all-cause death, myocardial infarction, coronary revascularization, acute kidney failure, or ischemic stroke within 90 days after randomization. Secondary end points included a composite of cardiac complications other than myocardial infarction (arrhythmias, heart failure, and nonfatal cardiac arrest). Results: Of the 1424 analyzed veterans (mean age, 69.9 [SD, 7.9] years; 1393 male [97.8%]; 268 Black [18.8%]; 48 Hispanic [4.1%]; 1071 White [75.2%]), 1297 (91.1%) underwent vascular surgical procedures. The mean hemoglobin difference between transfusion strategies was 2.0 g/dL on day 5 after randomization. The primary outcome rate in the liberal group was 9.1% (61 of 670) compared with 10.1% (71 of 700) in the restrictive group (relative risk, 0.90; 95% CI, 0.65-1.24). The secondary end point of cardiac complications without myocardial infarction, which was 1 of 5 secondary end points, occurred in 5.9% (38 of 647) of patients in the liberal group and 9.9% (67 of 678) of patients in the restrictive group (relative risk, 0.59; 99% CI, 0.36-0.98). Conclusions and relevance: After major vascular or general surgery operations among patients at high risk of a cardiac event, a liberal transfusion strategy did not reduce 90-day death or major ischemic outcome rates compared with a restrictive strategy. Trial Registration: ClinicalTrials.gov Identifier: NCT03229941.