Objective To investigate the expression and clinical significance of high-sensitivity C-reactive protein(hs-CRP) and interleukin-6 (IL-6) in patients with recurrence of atrial fibrillation(AF) after radiofrequency catheter ablation.Methods Retrospective analysis was made among a total of ninety-seven cases of paroxysmal atrial fibrillation treated by radiofrequency catheter ablation in Chaoyang Central Hospital from January 2011 to December 2015.The patients were divided into recurrent group and successful group,depending on whether they had recurrence in six months after radiofrequency catheter ablation.The concentration of the patients'' serum hs-CRP and IL-6 before radiofrequency catheter ablation were detected and compared with those of the healthy subjects (control group) during the same period.Logistic regression analysis was used to analyze the risk factors in atrial fibrillation recurrence after radiofrequency catheter ablation.Results The levels of serum hs-CRP was (4.6±1.2) mg/L and IL-6 was(0.19±0.05) mg/L in the recurrent group,higher than those in the control group ((2.0±0.3) mg/L,(0.10±0.03) mg/L).The differences between the two groups were statistically significant (P=0.037,0.046).According to the atrial fibrillation recurrence,97 patients were divided into recurrent group (29 cases) and successful group (68 cases).The levels of serum hs-CRP and IL-6 in the recurrent group were (5.61±2.30) mg/L,(0.30±0.07) mg/L,respectively,while the data of the successful group were (3.29±1.62) mg/L,(0.15±0.06) mg/L,respectively.There were significant differences between the two groups (P=0.047,0.036).Logistic regression analysis showed that the left ventricular anterior and posterior diameter (OR=2.073,95%CI:1.078~4.126,P=0.031),levels of serum hs-CRP (OR=1.943,95%CI:1.025-3.698,P=0.042) and serum IL-6 (OR=2.071,95%CI:1.089-10.101,P=0.027) were all risk factors in atrial fibrillation recurrence after radiofrequency catheter ablation.Conclusions Inflammatory factors might be involved in the occurrence and maintenance of atrial fibrillation.The expression levels of serum hs-CRP and IL-6 are related to the recurrence of AF,which could be independent predictors of postoperative atrial fibrillation recurrence.