OBJECTIVES: The CArdioSurgEry Atrial Fibrillation (CASE-AF) registry is a prospective, multi-centre study for collecting and analysing real-world data of surgical AF treatment. This study aimed to evaluate outcomes of surgery for long-standing persistent AF at one year.

METHODS: In total, 17 centers consecutively include all eligible patients with continuous AF lasting for ≥1 year. Exclusion criteria are missing informed consent or age <18 years. For patient-reported outcomes measures, the EHRA score was used. No presence of AF (based on ECG findings including Holter ECG and/or implanted devices), no re-ablation, no further cardioversion, and no re-hospitalization due to AF after a 3 months blanking period defined no AF recurrence at one year.

RESULTS: From January 2017 to January 2020, a total of 1115 patients were enrolled in CASE-AF. Of them, 202 patients (mean age 69.7±7.8 years, 27.2% female) underwent surgical ablation of long-standing persistent AF (study cohort), mostly accompanied by left atrial appendage closure (n = 180 [89%], resection n = 75 [42%]) and predominantly performed as concomitant (n = 174 [86%]) and left atrial only procedure (n = 144 [71%]). Early mortality (30 d) was 2.0% and morbidity was low. At follow up (median 14.4 months, IQR, 12.7-17.6 months, 100% complete), 106 patients (56%) had no AF recurrence and 93% of them were asymptomatic. AF recurrence was accompanied by AF-related re-hospitalization (n = 12, p = 0.003), DC shock cardioversion (n = 23, p < 0.001), AF ablation (n = 7, p = 0.003), and stroke (n = 3, p = 0.059). Multivariable analysis identified cryoablation, predominantly performed endocardially including additional left atrial (74%) and biatrial (42%) lesions, as a significant factor for freedom from AF recurrence (odds ratio 2.7, 95% confidence interval 1.07-6.79, p = 0.035).

CONCLUSIONS: According to CASE-AF, surgical ablation of LSPAF is most effective when concomitantly performed using endocardial cryoablation. Ongoing follow up allows further elucidation of efficacious treatment strategies.

CLINICAL REGISTRATION NUMBER: CASE-AF Registry, ClinicalTrials.gov, NCT03091452, registered March 27, 2017.