Objective: To compare the effects of intraoperative cell salvage (ICS) and preoperative autologous blood donation (PABD) on postoperative coagulation and platelet function in patients undergoing cardiac surgery, and to explore the underlying mechanisms.

Methods: A retrospective analysis was conducted on 212 patients who under went either ICS (n = 127) or PABD (n = 85) between June 2022 and May 2025. Hematologic parameters (including platelet count), coagulation indices (prothrombin time [PT], activated partial thromboplastin time [APTT], fibrinogen, D-dimer) and platelet function (thromboelastography [TEG], platelet aggregation test, and platelet activation markers) were measured preoperatively and within 24 hours postoperatively.

Results: Baseline characteristics and incidences of transfusion-related adverse reactions did not differ significantly between groups. Postoperatively, the ICS
group showed significantly lower platelet counts, prolonged PT and APTT, reduced fibrinogen levels, and elevated D-dimer levels compared with the PABD group. TEG showed a longer reaction time (R) in the ICS group, indicating de layed thrombus formation. The platelet aggregation rate and activation marker expression were also more markedly impaired in the ICS group (both P < 0.05). Conclusion: ICS is associated with more pronounced platelet depletion and coagulation factor loss, likely due to mechanical shear stress and the washing process, whereas PABD better preserved hemostatic components. Both methods are safe, but PABD may be more suitable for patients at risk of coagulation disorders.