Abstract Background Treatment with catheter ablation (CA) as rhythm control is increasingly used in atrial fibrillation (AF). Short-term AF recurrence after first-time CA varies from 10-30% in paroxysmal AF (PAF) and up to 50% in persistent AF (PeAF). Strategies to optimize outcome is still an ongoing challenge. Whether the sedation strategy, conscious sedation (CS) or general anesthesia (GA), has any impact on AF recurrence has yet to be determined. Currently no guidelines are available regarding sedation strategy. Objective To investigate the impact of sedation strategy in CA for PAF and PeAF on AF recurrence. Method This nationwide retrospective registry study was conducted using large real-life data from Danish mandatory registries. All patients above 18 years, that underwent CA for AF from January 1st 2010 to December 31st 2018, were identified and included at the date of ablation. Exposure of interest was type of anesthesia, and patients were stratified into CS or GA. Primary endpoint was recurrent AF after a 3-months blanking period, defined by a composite endpoint of first-reached endpoint of either use of antiarrhythmic drugs (AAD), AF-admission, electrical cardioversions or AF re-ablation. 5-year risk of recurrent AF was examined by the Aalen-Johansen estimator, taking the competing risk of death into account. Subgroup analysis of PAF and PeAF was performed. Results The study cohort consisted of 6,423 patients with first-time CA. 3,958 patients with PAF and 2,465 patients with PeAF. 5,058 patients underwent the procedure in CS, and 1,365 in GA. 5-year cumulative incidence of recurrent AF was higher in the CS group for both PAF and PeAF with 49,3% and 58,9% respectively, compared to 39,0% for PAF and 46,2% for PeAF in the GA group (Figure 1). A total of 3,242 patients reached the primary endpoint. Admissions for AF was the predominant endpoint for both CS and GA (1323, 42,0%). When subdivided into PAF and PeAF, admission for AF was still the predominant endpoint (Table 1). Conclusion Reduction of AF recurrence after CA is a continuing challenge. This study shows that the sedation strategy is important, and that the risk of recurrence is significantly lower for CA performed in GA. Subgroup analysis of PAF and PeAF, shows that regardless of AF type, recurrence rates are significantly lower in the GA group.Figure 1Table 1