Abstract
BACKGROUND: The 4S-AF scheme, which comprises four domains related to atrial fibrillation (AF), stroke risk (St), symptom severity (Sy), severity of AF burden (Sb), and substrate (Su), represents a novel approach for structurally characterizing AF. This study aimed to assess the clinical utility of the scheme in predicting AF recurrence following radiofrequency catheter ablation (RFCA). METHODS: We prospectively enrolled 345 consecutive patients with AF who underwent initial RFCA between January 2019 and December 2019. The 4S-AF scheme score was calculated and used to characterize AF. The primary outcome assessed was AF recurrence after RFCA, defined as any documented atrial tachyarrhythmia episode lasting at least 30 seconds. RESULTS: In total, 345 patients (age 61 (interquartile range (IQR): 53-68) years, 34.2% female, 70.7% paroxysmal AF) were analyzed. The median duration of AF history was 12 (IQR: 3-36) months, and the median number of comorbidities was 2 (IQR: 1-3), and 157 (45.5%) patients had left atrial enlargement. During a median follow-up period of 28 (IQR: 13-37) months, AF recurrence occurred in 34.4% of patients. After eliminating the Sy and St domains, both the 4S-AF scheme (hazard ratio (HR) 1.38, 95% confidence interval (CI): 1.19-1.59, p < 0.001) and severity of burden and substrate of atrial fibrillation (2S-AF) scheme scores (HR 1.59, 95% CI: 1.33-1.89, p < 0.001) were independent predictors of AF recurrence following RFCA. For each domain, we found that the independent predictors were Sb (HR 1.84, 95% CI: 1.25-2.72, p = 0.002) and Su (HR 1.71, 95% CI: 1.36-2.14, p < 0.001). Furthermore, the 4S-AF (area under the curve (AUC) 65.2%, 95% CI: 59.3-71.1) and 2S-AF scheme score (AUC 66.2%, 95% CI: 60.2-72.1) had a modest ability to predict AF recurrence after RFCA. CONCLUSIONS: The novel 4S-AF scheme is feasible for evaluating and characterizing AF patients who undergo RFCA. A higher 4S-AF scheme score is independently associated with AF recurrence after RFCA. However, the ability of the 4S-AF scheme to discriminate between patients at high risk of recurrence was limited.