Inflammatory biomarkers for predicting postoperative atrial fibrillation in cardiac surgery

Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery associated with adverse outcomes. Systemic inflammation is implicated in POAF pathogenesis, suggesting inflammatory biomarkers may have predictive value. This study investigated the predictive capacity of readily accessible inflammatory markers for POAF during the early postoperative period in the cardiac intensive care unit, particularly within the 48-72-hour window when POAF most commonly occurs. In this prospective, single-center study, we enrolled 70 patients undergoing elective cardiac surgery with cardiopulmonary bypass. We measured preoperative and postoperative (24h, 48h) levels of neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), C-reactive protein (CRP), interleukin-6 (IL-6), and interleukin-17A (IL-17A). POAF was systematically monitored. We assessed the predictive value of these markers using ROC curve analysis and logistic regression, adjusting for clinical risk factors. The coronary cohort showed that the NLR at both 24 hours and 48 hours were the most discriminative markers for predicting POAF, with PCR at 48 hours achieving a moderate AUC of 0.66. In multivariate regression models, PCR at 48 hours (<i>P</i> = 0.009) and age (<i>P</i> = 0.046) emerged as significant predictors, while NLR and CPB duration were moderately correlated with the occurrence of POAF. In contrast, within the valvular patient subgroup, the NLR again exhibited promising predictive value, along with increased markers of tissue injury such as CK, LDH, and creatinine. Readily accessible postoperative inflammatory markers, particularly NLR at 24 hours and CRP at 48 hours, demonstrated moderate predictive value for POAF in patients undergoing elective cardiac surgery. These markers, especially NLR and CRP, may potentially contribute to improved POAF risk stratification in clinical practice when combined with clinical risk factors. Furthermore, our analysis also indicates that preoperative IL-17A levels may influence the occurrence of POAF. Therefore, alongside CRP and NLR, preoperative IL-17A can be considered a potentially significant marker for atrial fibrillation following cardiac surgery. However, these findings are preliminary and require validation in larger, multi-center studies to confirm their clinical utility and inform preventative strategies.