Ferroptosis Exists in Ischemia Reperfusion Injury after Cardiac Surgery with Cardiopulmonary Bypass.

Ischemia-reperfusion (IR) injury commonly arises during cardiac surgery involving Cardiopulmonary Bypass (CPB), and it has relationship with ferroptosis in mice. However, the exact role of ferroptosis in the human cardiac damage caused by cardiac surgery remains unclear. Basic patient data and perioperative period information were collected, and clinic indicators related to cardiac function were detected to assess the extent of cardiac injury. Cardiac tissue samples were collected to determine histopathological changes, ultrastructure of mitochondrial and hallmarks of ferroptosis. 25 patients were involved in this study. In the present study, we observed a significant increase in the clinical indicator hs-cTnT, with levels rising more than 1393 ± 242 folds (P < 0.0001) following the cardiac surgery. Masson staining revealed a notable increase in fibrosis levels by 2.282 ± 0.259% (P = 0.0009). Furthermore, there was a significant elevation in lipid peroxidation, as evidenced by a 61.42 ± 17.33% increase in MDA (P = 0.0006). Additionally, we observed notable swelling, decreased mitochondrial crista, and even fragmented mitochondria. Notably, changes in the marker gene of ferroptosis were observed, with PTGS2 showing a 6.437 ± 0.81 folds increase (P < 0.0001). Furthermore, key regulators such as SLC7A11 and GPX4 proteins exhibited a reduction of 97.33 ± 25.78% (P = 0.0068) and 60.59 ± 14.93% (P = 0.0071), respectively, indicating the occurrence of ferroptosis following the surgery. Ferroptosis exists in myocardial IR injury caused by cardiac surgery with CPB, indicating that targeting ferroptosis could serve as a potential strategy for myocardial protection against CPB-induced IR injury. The trial has been registered in Chinese Clinical Trial Registry (ChiCTR, No. ChiCTR2200061995) on July 16th, 2022.