Extracellular Vesicles as Mediators of Endothelial and Tubular Injury in Cardiac Surgery-Associated Acute Kidney...

Cardiac surgery represents a cornerstone of modern cardiovascular medicine, yet it is intrinsically linked to significant systemic stress responses that can compromise remote organ function. Among postoperative complications, cardiac surgery-associated acute kidney injury (CSA-AKI) remains a significant clinical challenge characterized by high morbidity and complex pathophysiology. While hemodynamic instability and ischemia-reperfusion injury are established risk factors, renal dysfunction frequently persists despite optimal perfusion. This observation suggests the involvement of potent circulating mediators in cellular injury. Extracellular vesicles (EVs) are essential for intercellular communication and serve as central hubs for transporting bioactive lipids, proteins, and genetic material. Accumulating evidence indicates that the mechanical and oxidative stress inherent to cardiopulmonary bypass triggers substantial release of EVs from platelets, erythrocytes, and injured vascular tissues. These vesicles may function as vectors that traffic oxidized mitochondrial components and pro-inflammatory cargo to the renal parenchyma. This signaling cascade appears to disrupt renal homeostasis through a proposed "dual-hit" mechanism involving the induction of endothelial dysfunction and endothelial-to-mesenchymal transition (EndMT), followed by tubular epithelial injury via mitochondrial fragmentation, redox imbalance, and downregulation of anti-aging factors. The complexity of these EV-mediated interactions may contribute to an incomplete understanding of why specific patient phenotypes fail to recover. This narrative review examines the mechanisms of surgery-induced EV biogenesis, the molecular pathogenesis of endothelial and tubular damage, and the role of intercellular crosstalk. Additionally, we discuss future perspectives on targeting the "EV vector" through therapeutic apheresis and mitochondrial pharmacotherapy to potentially improve clinical outcomes in high-risk surgical patients.