Role of fibroblast growth factor-23 (FGF-23) in the prediction of postoperative atrial fibrillation after coronary artery bypass surgery.

Introduction: Fibroblast growth factor-23 (FGF-23) is a bone-derived hormone which had shown a significant association with the occurrence of atrial fibrillation (AF) in patients with chronic kidney disease. We hypothesized that FGF-23 could be a very useful predictive biomarker for atrial remodeling and in turn for postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG). We also looked at the correlation of cardiac remodeling in right atrial biopsy and its correlation with POAF and with the FGF-23 level. Methods: This study was a single-center cross-sectional observational study. All the patients who were planned for CABG with no prior history of AF were included in the study. All the patients were tested for preoperative serum FGF-23 level. During CABG, biopsy specimen of the right atrial appendage was sent for histopathology evaluation. All patients were monitored for POAF until discharge from the hospital. Results: This study involved 60 patients who underwent elective CABG. Multivariate analysis revealed a significant association between preoperative FGF-23 levels with the occurrence of POAF (p < 0.001). The area under the curve of FGF-23 was 0.894 with a sensitivity of 92.3% and specificity of 87.23%. The cut-off value for serum FGF-23 levels was found to be 6.50 ng/ml. Analysis of biopsy specimens revealed that the presence of hypertrophic myocytes had a significant association with the occurrence of POAF/POAE and with FGF-23. Conclusion: Preoperative FGF-23 levels can predict the incidence of POAF in post-CABG patients. Histopathologically, the presence of hypertrophic myocytes correlated well with the occurrence of POAF.