Predictive value of systemic inflammatory indicators in atrial fibrillation risk stratification after coronary artery bypass grafting

The first postoperative atrial fibrillation (PAF) is one of the most frequent complications after coronary artery bypass grafting (CABG). Currently, the pathogenesis of PAF is not fully studied, but the importance of inflammation in PAF development is undeniable. The investigation is oriented to the further study of inflammatory hypothesis of PAF development after coronary artery bypass grafting. Objective. To investigate the nosocomial dynamics of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune inflammation index (SII), as well as to evaluate the correlation of these indicators with primary paroxysmal AF after CABG. Material and methods. The study included 80 patients who underwent routinely CABG in the conditions of cardiac surgery department of N.V. Sklifosovsky Research Institute of Emergency Medicine. Arrhythmic episode, registered at an ECG recording part during Holter monitoring or at a bedside monitor in the conditions of cardiac surgery department, considered to be the first paroxysmal PAF. Patients were divided into 2 groups depending on development of AF: 20 patients with PAF (90% (n=18) of men), 60 patients without PAF (88.33% (n=53) of men). The neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR) and the systemic immune inflammation index (SII) were calculated in patients before CABG, on the 1st day and on the 7th-10th day after surgery. Results. The correlation between NLR level and paroxysmal PAF, confirmed by data of univariate analysis (OR=0.29, 95% CI 0.1000—0.8647, p=0.026) was revealed on the 7th-10th postoperative day in the comparison between groups. Threshold value of the predictive NLR on the 7th-10th day after CABG, according to the data of ROC analysis, was >3.00 (AUC=0.642, p=0.056). Moderate positive correlations between NLR on the 7th-10th day and time of aorta clamp (r=0.354; p=0.001), time of assisted circulation (r=0.240; p=0.031), leykocytes’ rate on the 7th day after CABG (r=0.521; p=0.042), PLR on the 7th postoperative day (r=0.290; p=0.008) were found according to the results of multiple correlation analysis. Conclusion. Surgical myocardial revascularization is the reason of systemic immune inflammation in patients of cardiac surgery unit, that is confirmed by statistically significant increase of the indicators of platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio and systemic immune inflammation index on the 1st and 7th days after coronary artery bypass grafting. At the same time, only the ratio of absolute neutrophil count to absolute lymphocyte count can potentially show the involvement of inflammation in pathogenesis of postoperative atrial fibrillation development. The importance of platelet-to-lymphocyte ratio and systemic immune inflammation index within risk stratification of postoperative atrial fibrillation development is unclear and should be further studied.