Background: Radiofrequency catheter ablation (RFCA) for long-standing persistent atrial fibrillation (LSP-AF) remains challenging, especially in patients with very long atrial fibrillation (AF) duration. Objective: To evaluate the long-term outcomes of RFCA in patients with LSP-AF lasting ≥ 3 years, and to identify predictors for AF recurrence. Methods: This retrospective study included 151 patients with LSP-AF undergoing first-time RFCA. Procedure was performed with wide antral pulmonary vein isolation (PVI) based individualized ablation strategy, guided by ablation index (AI). Patients were followed up for ? 18 months, and recurrence predictors were determined. Results: Enrolled patients (mean persistent AF duration: 7.6 ± 5.2 years) had a mean age of 65.3 ± 9.2 years and the median left atrial diameter (LAD) was 45.0 (42.0-49.0) mm. PVI was achieved in all, followed by modified left posterior wall isolation (PWI) in 147 patients. Additional ablation after PWI was performed in 88 patients. During the 18-month follow-up, the overall success rate was 74.2%. Multivariate analysis identified AF duration (HR 1.078; 95% CI 1.020-1.139; P = 0.007), LAD (HR 1.069; 95% CI 1.010-1.132; P = 0.022), and pre-procedure CRP (HR 1.063; 95% CI 1.010-1.117; P = 0.018) as independent predictors of AF recurrence. Among patients with PVI and PWI, those without empirical additional ablation (EAA) had a lower but not statistically significant recurrence rate (18.6%) than those with EAA (31.8%, P = 0.076). Conclusion: Among LSP-AF patients, the long-term efficacy of AI-guided RFCA is acceptable, especially in selected patients. However, EAA after PVI and PWI may be unhelpful.

The authors have declared no competing interest.

This study was funded by National Natural Science Foundation of China, grant number 82370324, Clinical Research Plan of SHDC (SHDC2023CRD008), Zunyi Science and Technology Bureau (2018-191), Clinical Research Plan of Shanghai General Hospital (CCTR-2022B09).

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ethical approval was granted by the Ethics Committee of Shanghai general hospital.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

The figure was created by SPSS 25.0 (IBM Corp., Armonk, NY, USA) and GraphPad Prism (version 8.0).