Background: The 4S-AF scheme, consisting of four domains related to atrial fibrillation (AF) [stroke risk (St), symptoms (Sy), severity of AF burden (Sb), and substrate (Su)], represents a novel approach for the structural characterization of AF. We aimed to assess the clinical utility of the scheme in predicting AF recurrence after 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: Of 345 patients [age 61 (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. Both 4S-AF scheme score (HR 1.38, 95% CI: 1.19?1.59, P<0.001) and 2S-AF scheme by eliminating the Sy and St domains (HR 1.59, 95% CI: 1.33?1.89, P<0.001) were independent predictors of AF recurrence after 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, 4S-AF scheme score (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 and aids us in identifying patients with a high risk of AF recurrence after RFCA.

The authors have declared no competing interest.

This study was supported by National Natural Science Foundation of China (Grant No. 81500365), Beijing Natural Science Foundation (Grant No. 7172040), Beijing JST Research Funding (Grant No. ZR-202212), and Capital Medical University Major Science and Technology Innovation Research and Development Special Fund (Grant No. KCZD202201).

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This study was designed and performed in accordance with the Declaration of Helsinki for Human Research and was approved by the Beijing Anzhen Hospital Ethics Committee (Approval No: 2024103X).

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