Abstract:Objective To investigate the relationship between pre-operative plasma myeloperoxidase (MPO) level and recurrence of atrial fibrillation (AF) in patients after catheter ablation. Methods The prospective study included 45 patients with atrial fibrillation who underwent catheter ablation in our hospital from September 2017 to March 2018. The pre-operative plasma MPO level, echocardiography and other clinical examinations were conducted in all patients. The patients were followed up for 1 year and were divided into recurrent group and non-recurrent group according to the recurrence of atrial fibrillation. Results During 12 months follow-up period, the recurrence rate after atrial fibrillation was 31.1% (14/45), including 25.0% (8/32) of paroxysmal AF and 46.1% (6/13) of persistent AF. Further Cox multivariate regression analysis showed pre-operative MPO > 50.5 ng/ml [HlR = 4.292, (95% CI: 1.153, 15.985, P?=?0.030] was significantly related to AF recurrence. Conclusion Pre-operative plasma MPO level > 50.5?ng/ml is related to AF recurrence in patients after catheter ablation.