Background EAST-AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial) demonstrated clinical benefit of early rhythm-control therapy (ERC) in patients with new-onset atrial fibrillation (AF) and concomitant cardiovascular conditions compared with current guideline-based practice. This study aimed to evaluate the generalizability of EAST-AFNET 4 in routine practice. Methods and Results Using a US administrative database, we identified 109 739 patients with newly diagnosed AF during the enrollment period of EAST-AFNET 4. Patients were classified as either receiving ERC, using AF ablation or antiarrhythmic drug therapy, within the first year after AF diagnosis (n=27 106) or not receiving ERC (control group, n=82 633). After propensity score overlap weighting, Cox proportional hazards regression was used to compare groups for the primary composite outcome of all-cause mortality, stroke, or hospitalization with the diagnoses heart failure or myocardial infarction. Most patients (79 948 of 109 739; 72.9%) met the inclusion criteria for EAST-AFNET 4. ERC was associated with a reduced risk for the primary composite outcome (hazard ratio [HR], 0.85; 95% CI, 0.75-0.97 [P=0.02]) with largely consistent results between eligible (HR, 0.89; 95% CI, 0.76-1.04 [P=0.14]) or ineligible (HR, 0.77; 95% CI, 0.60-0.98 [P=0.04]) patients for EAST-AFNET 4 trial inclusion. ERC was associated with lower risk of stroke in the overall cohort and in trial-eligible patients. Conclusions This analysis replicates the clinical benefit of ERC seen in EAST-AFNET 4. The results support adoption of ERC as part of the management of recently diagnosed AF in the United States.
