Th17/Treg Ratio in Serum Predicts Onset of Postoperative Atrial Fibrillation After Off-Pump Coronary Artery Bypass Graft Surgery

Background The aim of this study is to identify whether the balance between T helper 17 (Th17) cells and CD4(+) CD25(+) Foxp3(+) regulatory T (Treg) cells could predict the postoperative atrial fibrillation (POAF) after coronary artery bypass graft surgery (CABG). Methods We enrolled 88 patients from Xinhua Hospital who received off-pump CABG (OPCABG) surgery. The baseline characteristics of patients were recorded. The preoperative variables C-reactive protein (CRP) level, left atrial (LA) volume, EuroSCORE I score, CHADS(2) score, and CHA(2)DS(2) -VASc score were calculated at enrolment. Circulating Th17 and Treg cell frequencies were determined by flow cytometry, and expressions of Th17- and Treg-related cytokines were measured by enzyme-linked immunosorbent assay (ELISA). Results Compared to patients without POAF, the CRP level and peripheral circulating Th17 cell were significantly increased in POAF patients. Th17/Treg ratio was positively correlated with CRP level, LA volume, CHADS 2 score, and CHA(2)DS(2)-VASc score. The areas under the receiver-operating characteristic (AUC) curves of Th17/Treg ratio for predicting POAF occurrence was higher than that of CRP level, LA volume, CHADS(2) score and CHA(2)DS(2)-VASc score. Th17/Treg ratio combined with CRP level has the highest AUC and a greater balance between sensitivity and specificity for predicting POAF. Conclusions Our data suggest that a Th17/Treg imbalance due to a Th17 shift, representing a pro-inflammatory tendency, participates in the development of POAF. Combining the Th17/Treg ratio with CRP level may provide a more accurate, sensitive, and specific indicator for prediction of POAF.