Elevated Serum Fibroblast Growth Factor 23 (FGF-23) Perseveres into a Convalescence Period After Elective Cardiac Surgery, with Receptor Activator of Nuclear Factor kB Ligand (RANKL) and Cartilage Oligomeric Matrix Protein (COMP) Being Part of the Peri-Surgical Pro-Arteriosclerotic Inflammatory Response

Background: Receptor activator of nuclear factor k B ligand (RANKL), osteoprotegerin (OPG), cartilage oligomeric matrix pro-tein (COMP), bone morphogenetic protein (BMP-2), and fibroblast growth factor 23 (FGF-23) are involved in in-flammation, calcium deposition, and fibrosis of blood vessels. Acute changes in these factors may contribute to the progression of arteriosclerosis, especially if their elevated serum levels persist postoperatively.Material/Methods: A total of 90 patients (79 White, 4 African American, and 7 Other) undergoing elective heart surgery were en-rolled in the study. Blood was collected before surgery and after surgery at 24 hours, 7 days, and 3 months to allow for longitudinal comparisons. After the plasma isolation, several biomarkers levels were studied using an enzymatic-linked assay. Demographic and clinical information were obtained from electronic health records.Results: At 24 hours after surgery, RANKL (RANKLbaseline=248.7 +/- 215.7 vs RANKLt24h=376.4 +/- 329.7; P=0.035), and BMP-2 (BMP-2baseline=283.7 +/- 255.4 vs BMP-2t24h=482.4; P=0.015) were significantly elevated compared to baseline, with levels returning to baseline at 7 days. FGF-23 increased significantly from baseline (FGF-23baseline=1020 +/- 1210) to 7 days (FGF-237d=2191 +/- 5188; P=0.029) and remained significantly higher than baseline at 3 months (FGF-233m=2041 +/- 3521; P=0.044). White blood cells (WBC) remained elevated at discharge (WBCbaseline=6.8 +/- 2.1 vs WBC24h=15.0 +/- 5.3 vs WBCdischarge =8.8 +/- 3.4). IL-8 and C-reactive protein normalized at 3 months. Estimated blood loss was significantly correlated with RANKL at 24 hours (r2=0.33; P=0.035). Serum creatinine levels af-ter surgery at 24 hours (r2=0.41; p=0.008) and 7 days (r2=0.59; P=0.000) was strongly correlated with COMP. Conclusions: Persistent elevation of serum FGF-23 indicates a potential for accelerated arteriosclerosis after cardiac surgery.