Clinical utility of the 4S-AF scheme in predicting recurrence of atrial fibrillation after radiofrequency catheter ablation
Authors: Cui Naiyuan , Li Haiwei , Sun Weiping , Wang Zefeng , Yuan Zhongyu , Zhu Botao , Liu Yutong , Liu Huanfu , Wu Yongquan , Zhang Xiaoping 
Published: July 2024

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–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.

CLINICAL PERSPECTIVE

What Is New?

The 4S-AF scheme can be used to characterize and assess patients with atrial fibrillation (AF) who will undergo radiofrequency catheter ablation (RFCA).

A higher 4S-AF scheme score and 2S-AF scheme score modified by eliminating the Sy and St domains of the 4S-AF scheme score were significantly associated with an elevated atrial fibrillation (AF) recurrence rate after RFCA.

Severity of AF burden (Sb) and substrate (Su) domain scores were independently associated with AF recurrence outcomes after RFCA.

4S-AF scheme score and 2S-AF scheme score had modest predictive capability for AF recurrence.

What Are the Clinical Implications?

AF is a common cardiac arrhythmia and recurrence rates of AF after RFCA are substantial.

Using the 4S-AF scheme to characterize AF may aid in identifying high-risk patients who need to receive RFCA in terms of AF recurrence.

Compared to existing risk stratification methods, such as HATCH and CHA2DS2-VASc score, 4S-AF scheme score and 2S-AF scheme score had better clinical predictive capability of AF recurrence.