Neopterin as a predictive biomarker of postoperative atrial fibrillation following coronary artery bypass grafting

Background: The pathophysiology of postoperative atrial fibrillation (POAF) is multifactorial. Inflammation and increased oxidative stress play a significant role in POAF development. Neopterin, a biomarker of cellular immune response that enhances oxidative stress and increases the cytotoxic potential of activated macrophages and dendritic cells, was recently found as an independent predictive biomarker of non-operative atrial fibrillation. However, as far as we know, neopterin has never been investigated in POAF. Aims: The study aimed to assess neopterin concentration as a prognostic biomarker of POAF following coronary artery bypass grafting (CABG). Methods: One hundred one patients (80.2% males, 85% off-pump, 15% on-pump) were included. Blood samples were taken from patients for analysis of serum neopterin and high-sensitive C-reactive protein (hs-CRP) at three time points: (1) before operation (NP0); (2) on the first day after operation (NP1); and (3) between the fifth and eighth day after the procedure (NP5-8). All factors (preoperative, echocardiographic, and surgical), significant in univariate analysis, were included in a multivariable logistic regression analysis. Results: POAF occurred in 30 patients (30%). In the analyzed multivariable logistic regression models, the independent predictors of POAF occurrence were: higher NP0 concentration (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.02-1.38 for continuous and OR, 3.75; 95% CI, 1.39-10.1 for NP0 cut-off >8.7 nmol/l), higher body mass index (OR, 1.15; 95% CI 1.02-1.29), history of pulmonary disease (OR, 6.72; 95% CI 1.57-28), increased diastolic thickness of the interventricular septum (OR, 1.45; 95% CI, 1.14-1.83), and duration of operation (OR, 1.01; 95% CI, 1.03-1.36). Conclusions: We found that elevated neopterin concentration before CABG may be a predictive biomarker of POAF.