Serum sST2 Correlates with Left Atrial Low-Voltage Areas and Is Associated With Procedure Outcome in Patients Undergoing Atrial Fibrillation Radiofrequency Ablation

Objective: The present study was aimed to determine whether serum sST2，could be used as a marker of left atrial low voltage areas (LVAs) and it could be predicted the recurrence of AF in patients undergoing radiofrequency catheter ablation. Methods: 84 cases (average age 64.24 ± 10.17, including 54 paroxysmal AF and 30 persistent AF ) undergoing radiofrequency ablation were finally included in the study. Electroanatomical voltage mapping was employed to determine the extent of left atrial low-voltage. LVAs were defined as bipolar electrogram amplitudes ≤0.5 mV during sinus rhythm. The general clinical data and hematological indexes of all patients were collected before ablation. All patients were followed up at 3, 6 and 12 months after RF procedure. Results: The primary outcome was sST2 could be used as a marker for the left atrial low voltage area (OR = 1.054, P < 0.05), and the serum level of sST2 had predictive value for the recurrence of AF after RFA (HR 1.014, 95% CI 0.986-1.035, P = 0.035). It was showed that there was 95% AF-free survival after ablation in the lower levels of serum sST2 whereas there was only 59.6% AF-free survival in the higher levels of serum sST2 according to the subgroup analysis. (Log Rank test, P=0.027). The secondary outcome was that serum sST2 combined with left atrium ateroposterior diameter (LAD) can further improve the prediction ability. Conclusions: sST2 may be a new biomarker in the assessment of atrial fibrosis and is associated with the recurrence of atrial fibrillation after radiofreqency ablatation.