Myocardial Protection of Dexmedetomidine and Sevoflurane Pretreatment in Patients Undergoing Valve Replacement

Background and Objective: Surgical trauma stimulation during aortic valve replacement (AVR) with cardiopulmonary bypass (CPB) can induce inflammatory response, which causes myocardial ischemia-reperfusion and induces myocardial injury. This study aims to elucidate the involvement of the Toll-Like Receptor 4 (TLR4)/Nuclear Transcription Factor-κB (NF-κB) signaling pathway in regulating the inflammatory response and myocardial protection in patients undergoing AVR after dexmedetomidine combined with sevoflurane pretreatment. Materials and Methods: A retrospective analysis was conducted on the clinical data of 60 patients who underwent AVR with CPB at Nanchong Central Hospital. Based on their anesthetic regimen, 28 patients pretreated solely with sevoflurane were included in the control group, while 32 patients received a combined pretreatment of dexmedetomidine and sevoflurane were included in the experimental group. Results: At 24 hrs postoperatively, myocardial injury markers (creatine kinase isoenzyme, cardiac troponin I, N-terminal pro-brain natriuretic peptide), Partial Pressure of Carbon Dioxide (PaCO2), TLR4, NF-κB, inflammatory response markers (interleukin-6, interleukin-8, tumor necrosis factor-α, C-reactive protein) levels were significantly increased compared to preoperative values in both groups. However, these increases were less pronounced in the experimental group than in the control group. In contrast, oxygen index (OI) and Partial Pressure of Oxygen (PaO2) were significantly reduced postoperatively but were higher in the experimental group than in the control group (p<0.05). Conclusion: The combined pretreatment with dexmedetomidine and sevoflurane effectively enhances myocardial protection in patients undergoing AVR.