Clinical Research Directory

Inclusion Criteria 1. Patients were eligible for enrollment if they met all of the following criteria: 2. Adult patients aged 18 years or older. 3. Scheduled for elective cardiac surgery requiring cardiopulmonary bypass (CPB), specifically including open-heart valve repair or replacement. 4. Provided written informed consent from the patient or a legally authorized representative. Exclusion Criteria Patients meeting any of the following criteria were excluded from the study: 1. Neurological and Psychiatric Factors: Preoperative cognitive impairment or preexisting delirium. History of severe psychiatric disorders (e.g., schizophrenia, major depressive disorder) requiring significant psychotropic medication use. Major neurological disorders, including a history of stroke, severe cerebrovascular disease, or severe traumatic brain injury within the past six months. 2. Surgical and Systemic Factors: Scheduled for emergent or salvage cardiac surgery. Severe hepatic or renal dysfunction requiring dialysis. Current systemic infection, sepsis, or a state of severe immunosuppression. Pregnant or lactating women. 3. Pharmacological Factors: Administration of nitrates after hospital admission (due to potential confounding effects on endothelial function and nitric oxide signaling).