Role of sST2 in predicting recurrence of atrial fibrillation after radiofrequency catheter ablation

INTRODUCTION: Atrial fibrosis is associated with atrial fibrillation (AF) recurrence after ablation. This study aims to determine the relationship between soluble ST2 (sST2), a profibrotic biomarker, and AF recurrence after radiofrequency catheter ablation (RFCA). METHODS: AF patients referred for RFCA were consecutively included from October 2017 to May 2019. Baseline characteristics were collected, and sST2 levels were determined before ablation. Left atrial substrate mapping was performed after circumferential pulmonary vein isolation under sinus rhythm, and substrate was modified in low-voltage zones. A second procedure was recommended under recurrence. RESULTS: Two hundred fifty-eight patients (146 males, average age 61.0 ± 8.8) were included. After a medium follow-up of 13.5 months, 52 patients (20.2%) had recurrence and received a second procedure. Preoperative sST2 level in patients with recurrence was significantly higher than that in patients without (31.3 ng/mL vs 20.3 ng/mL, P < .001). In those undergoing second ablation, sST2 level in patients with new abnormalities during endocardial mapping was significantly higher than that in patients without (43.0 ng/mL vs 22.1 ng/mL, P < .001). An sST2 level over 26.9 ng/mL could predict AF recurrence with new abnormalities during endocardial mapping with a sensitivity of 100% and a specificity of 75.9%. Multiple logistic analysis showed that sST2 level was an independent predictor of AF recurrence with new abnormalities during endocardial mapping (P < .001). CONCLUSIONS: sST2 level was associated with new abnormalities during endocardial mapping and recurrence of AF after ablation. It might have significance in choosing treatment strategies for AF.