Abstract: Objective To investigate the changes in serum levels of endothelin-1 (ET-1) and connective tissue growth factor (CTGF) in patients with atrial fibrillation (AF) and their value for predicting recurrence of AF after radiofrequency ablation (RFCA). Methods Sixty-six patients with paroxysmal AF (PaAF) and 72 with persistent AF (PaAF) admitted in our hospital were recruited as AF group and 80 patients with sinus rhythm as the control group, and in all the participants, serum levels of ET-1 and CTGF were measured using ELISA and Western blotting. From 6 patients with AF and 6 with sinus rhythm undergoing cardiac surgery in our hospital, tissue samples of the right atrial appendage were taken intraoperatively for observation of structural changes of the cardiomyocytes, myocardial fibrosis and expression of ET-1 and CTGF protein. In AF group, the patients receiving RFCA were followed up for 6 months following the procedure for assessment of the outcomes. Results Compared with the control patients, the patients with AF showed obvious damages of the cardiomyocyte structure and myocardial fibrosis. Serum levels of ET-1 and CTGF levels were significantly higher in PaAF and PeAF groups than in the control group, and were higher in PeAF group than in PaAF group. In the patients with AF, serum ET-1 and CTGF levels were positively correlated with left atrial diameter (LAD) (P<0.05), and ET-1 was positively correlated with CTGF levels (P<0.05). In patients with postoperative AF recurrence, the serum levels of ET-1 and CTGF were significantly higher than those in patients without recurrence; serum ET-1 and CTGF levels before and after the operation were positively correlated with the recurrence of PeAF, and elevated serum levels of ET- 1 and CTGF were identified by logistic regression analysis as independent risk factors for postoperative recurrence of PeAF. Conclusion Serum levels of ET-1 and CTGF are significantly elevated in AF patients in positive correlation with AF duration. ET-1 and CTGF levels are higher in AF patients with postoperative recurrence, and they both have predictive value for recurrence of PeAF following RFCA.

Key words: endothelin-1; connective tissue growth factor; atrial fibrillation; clinical prognosis; radiofrequency ablation