High mobility group box 1 gene polymorphism is associated with the risk of postoperative atrial fibrillation after coronary artery bypass surgery

BACKGROUND: The inflammatory response triggered by cardiac surgery with cardiopulmonary bypass (CPB) is a primary cause of postoperative atrial fibrillation (POAF). The objective of this study was to determine the relationships between rs2249825 (C/G) polymorphism in high-mobility group box protein 1 (HMGB1) and POAF in patients who underwent coronary artery bypass grafting (CABG) under CPB. METHODS: A prospective cohort study was carried out between February 2011 and January 2014. Patients who had no history of atrial fibrillation undergoing CABG with CPB were recruited in this study, and were matched based on preoperative characteristics. Blood samples were obtained before, and at 4, and 24 h after CPB. HMGB1 level was measured by enzyme immunoassay. Patients were genotyped for single nucleotide polymorphisms of HMGB1 (rs2249825). Patients were genotyped for single nucleotide polymorphisms of HMGB1 (rs2249825) using pyrosequencing method. The primary clinical end point was the incidence of POAF after surgery. RESULTS: After matching, a total of 128 patients undergoing elective CABG with CPB were eligible for analysis. Plasma HMGB1 concentrations were increased 4 h after CPB (p <0.0001) and were still increased at 24 h (p <0.0001). The frequencies of CC, CG, GG genotypes were 21 (56.8 %), 29 (37.8 %), and 2 (5.4 %) in patients with POAF and 81.3, 16.5, and 2.2 % in patients without POAF (p = 0.016). CG + GG genotype was associated with high HMGB1 levels compared with the genotype CC at 4 h (p = 0.023), and 24 h (p = 0.015) after CPB. Multivariate analysis showed that age older than 60 years (OR = 1.40; 95 % CI: 1.03 to 1.89; p = 0.021) and allele G of polymorphisms (OR = 1.61; 95 % CI: 1.08 to 2.04; p = 0.034) were independent risk factors for POAF. CONCLUSIONS: The HMGB1 rs2249825 was associated with the susceptibility to POAF after CABG with CPB in a Chinese Han population.