A Longitudinal Study on the Perioperative Period of Cardiac Surgery — Multiple Interactions and Effects of Heparin Pleiotropy and Immune Microenvironment

Objective: To investigate the differences and trends of multiple monitoring indicators during the peri-cardiopulmonary bypass (CPB) period in patients undergoing heart transplantation (HTx) and ventricular assist device (VAD) implantation, and to explore the interaction and impact of unfractionated heparin (UFH) on the immune microenvironment under short-term, high-dose UFH administration. Methods: This prospective study enrolled 15 HTx and 19 VAD recipients between 2023 and 2024. Monitoring was conducted at five observation points: pre-CPB, 30 min post-CPB, before shutdown, 10 min post-heparin neutralization, and 30 min post-heparin neutralization. Coagulation function (TAT, PIC, D-dimer, etc.), inflammatory markers (IL-6, etc.), and endothelial injury markers (TM, etc.) were assessed, with Anti-Xa not monitored pre-CPB. Biochemical indicators, including liver and kidney function (ALT, AST, Cr, etc.), blood glucose, and lipid profiles (TC, TG, etc.), were measured only at pre-CPB, before shutdown, and 30 min post-heparin neutralization. Intergroup differences and trend changes were analyzed. Results: Significant differences were observed between the two groups in age, BMI, CPB duration, heparin dose, and aortic cross-clamp time, whereas no significant differences were found in priming volume or protamine sulfate (PS) dosage. Pre-CPB, PIC (P=0.019) and CK (P=0.044) were significantly higher in the HTx group, while TP (P=0.018) and CHE (P=0.023) were significantly higher in the VAD group. No significant intergroup differences were observed 30 min post-CPB. At the before shutdown timepoint, TAT (P=0.027), ALT (P=0.048), AST (P