Presenting Pattern of Atrial Fibrillation and Outcomes of Early Rhythm Control Therapy.

Background: Whether atrial fibrillation (AF) pattern or timing of AF therapy modifies the effectiveness of early rhythm control (ERC) is not known.

Objectives: This study sought to compare clinical characteristics and outcomes in patients presenting with different AF patterns on ERC vs usual care.

Methods: The effects of ERC were compared in first-diagnosed AF (FDAF), paroxysmal AF (paroxAF), and persistent AF (persAF) in this prespecified analysis of the EAST-AFNET 4 (Early treatment of atrial fibrillation for stroke prevention) trial. Associations between AF pattern and primary outcomes (first primary outcome: cardiovascular death, stroke, and hospitalization for heart failure and acute coronary syndrome; second primary outcome: nights spent in hospital per year) were compared over a mean follow-up of 5.1 years. Changes in health-related quality of life were assessed by the EQ-5D.

Results: FDAF patients (n = 1,048, enrolled 7 days after diagnosing AF) were slightly older (71 years of age, 48.0% female) than patients with paroxAF (n = 994, 70 years of age, 50.0% female) and persAF (n = 743, 70 years of age, 38.0% female). ERC reduced the primary outcome in all 3 AF patterns. Hospitalizations for acute coronary syndrome were highest in FDAF (incidence rate ratio [IRR]: 1.50; 95% CI: 0.83-2.69; P for interaction = 0.032) compared with paroxAF (IRR: 0.64; 95% CI: 0.32-1.25) and persAF (IRR: 0.50; 95% CI: 0.25-1.00). FDAF patients spent more nights in hospital (IRR: 1.38; 95% CI: 1.12-1.70; P for interaction = 0.004) than paroxAF (IRR: 0.84; 95% CI: 0.67-1.03), and persAF (IRR: 1.02; 95% CI: 0.80-1.30) patients. ERC improved health-related quality of life (EQ-5D score) in patients with paroxAF and persAF but not in patients with FDAF (P = 0.019).

Conclusions: ERC reduces the first primary composite outcome in all AF patterns. Patients with FDAF are at high risk for hospitalization and acute coronary syndrome, particularly on ERC. (Early treatment of atrial fibrillation for stroke prevention trial; ISRCTN04708680; Early Treatment of Atrial Fibrillation for Stroke Prevention Trial [EAST]; NCT01288352; Early treatment of Atrial fibrillation for Stroke prevention Trial [EAST]; EudraCT2010-021258-20).