Higher serum sST2 is associated with increased left atrial low-voltage areas and atrial fibrillation recurrence in patients undergoing radiofrequency ablation

Objective: To conduct a comprehensive analysis of prospectively measuring the concentration of soluble suppression of tumorigenicity 2 (sST2) to predict left atrial (LA) low-voltage areas (LVAs) and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFA). Methods: This was a prospective cohort study. A total of 84 patients, including 54 paroxysmal AF cases and 30 persistent AF cases who underwent RFA, were recruited. Electroanatomical voltage mapping determined the extent of LVAs. The serum level of sST2 was measured by enzyme-linked immunosorbent assay. All patients were followed for 12 months after the RFA procedure to verify AF recurrence. Results: The concentration of sST2 measured in the sample was 17.90–198.77 pg/mL, and the range of LA LVAs was 0–85.6%. The sST2 level positively correlated with LVAs (r = 0.40; P = 0.005). When comparing the top and bottom quartile, sST2 is significantly associated with LA LVAs (OR = 1.833, 95% CI: 1.582–2.011, P = 0.004). When compared with the 1st quartile group, the multivariable adjusted hazard ratios for AF recurrence after RFA were 1.57 (95% CI: 1.182–1.795) for the 4th quartile group, 1.44 (95% CI: 1.085–1.598) for the 3rd quartile group, and 1.27 (95% CI: 0.954–1.318) for the 2nd quartile group. The AF–free survival rates of patients with 1st quartile and 4th quartile sST2 levels after ablation were 95% and 59.6%, respectively (Log Rank test, P = 0.027). Conclusion: Elevated sST2 levels of AF patients were associated with higher LA LVAs and a significantly increased risk of recurrence. The circulating sST2 concentration might be a pre-diagnostic marker of AF recurrence after RFA.