Role of Omega-6 Fatty Acid Metabolism in Cardiac Surgery Postoperative Bleeding Risk

Area of Science:

• Cardiovascular Surgery
• Hematology
• Metabolomics

Background:

• Cardiac surgery often causes significant postoperative bleeding.
• Cardiopulmonary bypass (CPB) induces platelet dysfunction, affecting both platelet number and function.
• Platelet lipid metabolism is vital for function, but CPB-associated metabolic changes are poorly understood.

Purpose of the Study:

• To investigate the role of metabolic perturbations in platelet dysfunction following cardiac surgery.
• To explore the contribution of altered fatty acid metabolism to postoperative bleeding.

Main Methods:

• Prospective cohort study of 33 patients undergoing elective aortic valve replacement.
• Untargeted metabolomic analysis of platelet samples collected preoperatively and 6, 24 hours post-CPB.
• Comparison of metabolic profiles between patients with and without significant postoperative bleeding.

Main Results:

• A platelet metabolic signature involving fatty acid pathways was identified.
• Reduced arachidonic acid (AA) levels post-CPB correlated with increased bleeding and transfusion rates.
• Preoperative AA levels were inversely correlated with postoperative blood loss, independent of platelet count.

Conclusions:

• Inflammatory-related alterations in AA metabolism are characteristic of CPB-associated cardiac surgery.
• Preoperative AA levels may be a more reliable predictor of postoperative bleeding than platelet count.
• Targeting AA metabolism could offer new strategies for preventing bleeding after cardiac surgery.