Title:
Serum glial cell line-derived neurotrophic factor levels and postoperative cognitive dysfunction after surgery for rheumatic heart disease.

Abstract:
Postoperative cognitive dysfunction is an important complication of cardiac surgery with poor outcomes. Serum glial cell line-derived neurotrophic factor levels are decreased in patients with Alzheimer's disease, but the association between glial cell line-derived neurotrophic factor levels and postoperative cognitive dysfunction is poorly understood. The present study aimed to investigate the prognostic value of postoperative serum glial cell line-derived neurotrophic factor levels to predict postoperative cognitive dysfunction in patients with rheumatic heart disease undergoing heart valve replacement.
This was a prospective observational study of 80 patients undergoing elective heart valve replacement surgery from June 2015 to June 2016 at the Affiliated Hospital of Southeast Medical University. Cognitive functions were assessed 1 day before and 7 days after surgery. Serum glial cell line-derived neurotrophic factor levels were measured by an enzyme-linked immunosorbent assay before (T1) and 1 (T2), 2 (T3), and 7 (T4) days after surgery. Perioperative parameters were evaluated to assess the relationship between glial cell line-derived neurotrophic factors and postoperative cognitive dysfunction.
Postoperative cognitive dysfunction was identified in 38 patients (47.5%) 7 days after surgery. Average glial cell line-derived neurotrophic factor levels at 2 and 7 days after surgery in the postoperative cognitive dysfunction group were lower than in the nonpostoperative cognitive dysfunction group at the same time points (P < .001). ΔGlial cell line-derived neurotrophic factor (T1-T3) and Δglial cell line-derived neurotrophic factor (T1-T4) were identified as good predictors of postoperative cognitive dysfunction with threshold for postoperative cognitive dysfunction detection of 49.10 and 60.90, respectively.
The perioperative glial cell line-derived neurotrophic factor levels in patients with postoperative cognitive dysfunction were lower than in patients without postoperative cognitive dysfunction. Glial cell line-derived neurotrophic factor could be an effective predictor for the occurrence of postoperative cognitive dysfunction. The results reveal a potentially important role of decreased glial cell line-derived neurotrophic factor levels in postoperative cognitive dysfunction, with possible treatment targets.