Age and Outcomes of Early Rhythm Control in Patients With Atrial Fibrillation: Nationwide Cohort Study

Objectives: This study sought to investigate whether the effects of early rhythm control differ according to age. Background: Rhythm control, compared with usual care among patients recently diagnosed with atrial fibrillation (AF), was found to be associated with a lower risk of adverse cardiovascular outcomes. It is unclear whether the results can be generalized for older adults. Methods: This retrospective population-based cohort study included 31,220 patients with AF, from the Korean National Health Insurance Service database, undergoing rhythm control (antiarrhythmic drugs or ablation) or rate control therapy, initiated within 1 year of AF diagnosis. A composite outcome of cardiovascular death, ischemic stroke, hospitalization for heart failure, or myocardial infarction was compared in subgroups stratified by age. Results: Compared with rate control, early rhythm control was associated with a lower risk of the primary composite outcome in patients <75 years of age (HR: 0.80; 95% CI: 0.72-0.88). The protective association between early rhythm control and cardiovascular outcomes exhibited a linear decrease with advancing age, with declined benefits in patients ≥75 years of age (HR: 0.94; 95% CI: 0.87-1.03; P_interaction = 0.045). Trends toward lower risks of ischemic stroke (HR: 0.78; 95% CI: 0.67-0.90) and acute myocardial infarction (HR: 0.63; 95% CI: 0.41-0.97) were observed in the older adults. No significant differences in safety outcomes were found across different ages. Conclusions: The beneficial association of early rhythm control with cardiovascular outcomes was attenuated with increasing age, with the larger benefits in younger patients <75 years of age. No differences were found by age in treatment-related safety outcomes.