Brazilian Journal of Anesthesiology
https://bjan-sba.org/article/doi/10.1016/j.bjane.2026.844813
Brazilian Journal of Anesthesiology
Original Investigation

Relative hematocrit declines at the time of transfusion and postoperative outcomes after coronary artery bypass grafting: a retrospective cohort study

Queda relativa do hematócrito no momento da transfusão e desfechos pós-operatórios após cirurgia de revascularização do miocárdio: um estudo de coorte retrospectivo

Fatemeh Sadr, Arash Jalali, Ahmad Vakili-Basir, Mina Pashang, Khosro Barkhordari

http://dx.doi.org/10.1016/j.bjane.2026.844813 Braz J Anesthesiol, vol.76, n5, 844813, 2026
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Abstract

Background

Despite advances in patient blood management, the optimal hemoglobin threshold for Red Blood Cell (RBC) transfusion remains controversial. This observational study evaluated the association between the relative decline in Hematocrit (HCT) at the time of transfusion and postoperative outcomes in patients undergoing Coronary Artery Bypass Graft (CABG) surgery.

Methods

We conducted a retrospective cohort study of 629 patients who underwent CABG and received a transfusion at Tehran Heart Center Hospital, Iran, between March 2018 and December 2021. Based on the relative hematocrit reduction at the time of transfusion, patients were divided into two groups: Group A (≥ 40% change) and Group B (< 40% change). Early postoperative outcomes were compared between groups. Primary outcomes included mortality, hospital length of stay, intensive care unit length of stay, and intubation time. The composite secondary outcome comprised postoperative infection, renal failure, tamponade, and reoperation due to bleeding.

Results

There were no significant differences in primary outcomes, except hospital length of stay (p = 0.02). However, after adjustment for potential confounders, this difference was no longer significant (p = 0.32). Composite secondary outcomes were comparable between the two groups, with no significant difference observed (p = 0.85).

Conclusion

In patients undergoing CABG surgery, this study did not identify a significant difference in early postoperative outcomes between two transfused patient groups stratified by a 40% change in HCT. Further prospective studies are needed to determine clinical relevance of relative hematocrit decline at the time of transfusion as a potential adjunct to conventional transfusion triggers.

THC institutional review board

IR.TUMS.THC.REC.1402.070.

Keywords

Blood transfusion; Cardiac surgical procedures; Coronary artery bypass; Hematocrit; Postoperative complications

Resumo

Introdução

Apesar dos avanços no manejo de sangue do paciente (Patient Blood Management - PBM), o limiar ideal de hemoglobina para a transfusão de hemácias permanece controverso. Este estudo observacional avaliou a associação entre a queda relativa do hematócrito no momento da transfusão e os desfechos pós-operatórios em pacientes submetidos à cirurgia de revascularização do miocárdio (CRM).

Métodos

Conduzimos um estudo de coorte retrospectivo com 629 pacientes submetidos à CRM que receberam transfusão no hospital Tehran Heart Center, Irã, entre março de 2018 e dezembro de 2021. Com base na redução relativa do hematócrito no momento da transfusão, os pacientes foram divididos em dois grupos: Grupo A (variação ≥ 40%) e Grupo B (variação < 40%). Os desfechos pós-operatórios precoces foram comparados entre os grupos. Os desfechos primários incluíram mortalidade, tempo de internação hospitalar, tempo de permanência na unidade de terapia intensiva (UTI) e tempo de intubação. O desfecho secundário composto compreendeu infecção pós-operatória, insuficiência renal, tamponamento cardíaco e reoperação devido a sangramento.

Resultados

Não houve diferenças significativas nos desfechos primários, exceto no tempo de internação hospitalar (p = 0,02). No entanto, após o ajuste para potenciais fatores de confusão, essa diferença não foi mais significativa (p = 0,32). Os desfechos secundários compostos foram comparáveis entre os dois grupos, sem diferença significativa observada (p = 0,85).

Conclusão

Em pacientes submetidos à CRM, este estudo não identificou diferença significativa nos desfechos pós-operatórios precoces entre dois grupos de pacientes transfundidos estratificados por uma variação de 40% no hematócrito. Futuros estudos prospectivos são necessários para determinar a relevância clínica da queda relativa do hematócrito no momento da transfusão como um potencial adjuvante aos gatilhos transfusionais convencionais

Comitê de Ética Institucional (THC)

IR.TUMS.THC.REC.1402.070.

Palavras-chave

Transfusão de sangue; Revascularização do miocárdio; Procedimentos cirúrgicos cardíacos; Hematócrito; Complicações pós-operatórias

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Submitted date:
10/27/2025

Accepted date:
07/26/2026

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