To the Editor: Red blood cell (RBC) transfusion is commonly performed during on-pump cardiac surgery; however, excessive use may lead to adverse clinical outcomes and medical resources wastage.^[1] The call for precision transfusion necessitates the formulation of a patient-centered comprehensive patient blood management (PBM) approach.^[2] Such an approach should involve correct assessment of the impact of RBC transfusion on different populations and adoption of transfusion only in patients at risk to improve clinical outcomes.^[3] Our team has developed and validated an effective on–pump transfusion score (OPT-score) with eight variables for patients undergoing on–pump cardiac surgery to preoperatively stratify patients to low, medium, or high risk of perioperative RBC transfusion (PRT).^[4] In this study, we aimed to conduct a large-scale real-world retrospective study to evaluate the relationship between RBC transfusion and on-pump surgery hospital outcomes in patients with different transfusion risk levels, thereby providing robust evidence for establishing a patient–centered PBM for on-pump cardiac surgery patients.

This retrospective study adhered to the STROBE guidelines and was approved by the Fuwai Hospital Research Ethics Committees (No. 2024–2379). Due to the retrospective retrieval of the patient data, the informed consent was waived remitted. Adult patients (age >18 years) who underwent on–pump cardiac surgery between January 1, 2018 and December 31, 2022 were enrolled in the study. Patients with coagulation and platelet function disorders, undergoing heart transplants, mechanical circulatory assist devices conduction, and preoperative transfusion of any blood products were excluded. Patients with missing data that could not be retrieved from the original medical records were also excluded because our cardiopulmonary bypass (CPB) center has implemented a comprehensive PBM involving five blood conservation measures since 2018 [Supplementary Table 1, https://links.lww.com/CM9/C536]. Additionally, during this period, our center did not define the PRT risk for patients, and perfusionists decided on RBC transfusions independently of PRT risk. Therefore, this study is of a real-world nature. The patients enrolled in this study were stratified to low, medium, or high transfusion–risk based on the OPT-score developed in our previous research [Supplementary Table 2, https://links.lww.com/CM9/C536]. PRT was defined as the intraoperative and postoperative transfusion of RBC (in the operating room, in the intensive care unit [ICU], and on the ward after the operation).