Clinical characteristics and outcomes of first diagnosed atrial fibrillation: Insights from 2 prospective registries in Europe and Asia.

Background: Clinical characteristics and outcomes in patients with atrial fibrillation (AF) vary from diagnosis to advanced stages.

Objective: To assess differences in characteristics and outcomes between patients with first diagnosed AF and known AF.

Methods: A post hoc analysis of 2 prospective registries from Europe and Asia. The primary outcome was a composite of all-cause death and major adverse cardiovascular events, including thromboembolic events, cardiovascular death, acute coronary syndromes.

Results: Among 15,762 patients with AF, those with first diagnosed AF (n = 2081, age 68 ± 12 years, 41% women) were younger, more often women, with lower cardiovascular burden but higher prevalence of obesity, smoking, cancer. After a median follow-up of 693 days (interquartile range 365-735), first diagnosed AF was associated with a higher risk of the composite outcome (hazard ratio [HR] 1.311, 95% confidence interval [CI] 1.115-1.543), all-cause death (HR 1.389, 95% CI 1.153-1.673), major adverse cardiovascular events (HR 1.269, 95% CI 1.022-1.575), thromboembolic events (HR 1.495, 95% CI 1.043-2.145). Risk of the composite outcome in first diagnosed patients with AF was higher in late follow-up phase compared with early phase and among those enrolled in hospital settings than in outpatient settings. Patients with first diagnosed AF had a composite outcome risk similar to those with permanent AF (HR 0.921, 95% CI 0.771-1.101), but higher than those with paroxysmal (HR 0.650, 95% CI 0.535-0.790) and persistent AF (HR 0.676, 95% CI 0.554-0.826). A rhythm control strategy was associated with better outcomes than rate control.

Conclusion: The higher risk of first diagnosed patients with AF underscores the need for personalized, integrated management strategies that consider the heterogeneity of this arrhythmia to improve outcomes.