Aims: Clinicians increasingly encounter patients with young-onset atrial fibrillation (AF). Aim is to study clinical profile, AF progression, and outcome of patients with young-onset AF.
Methods and results: A total of 468 patients with paroxysmal or persistent AF starting <60 years of age were included. Clinical profile, AF progression, defined as development of permanent AF, and cardiovascular events were prospectively collected. Onset of AF was at 46 ± 10 years, 354 (76%) were men, 329 (70%) had paroxysmal AF, 50 (11%) had AF without risk factors or comorbidities, and 118 (25%) had familial AF. Hypertension was present in 207 (44%), heart failure in 44 (9%). During 7.2 (2.7-10.0) years, 56 (11%) had AF progression (2.0%/year). Progression rate in patients receiving antiarrhythmic drugs or pulmonary vein isolation during follow-up was not different from patients who did not. Multivariable determinants of AF progression included diastolic blood pressure [hazard ratio (HR) 1.031, 95% confidence interval (95% CI) 1.007-1.055; P = 0.010] and left atrial size (HR 1.055, 95% CI 1.012-1.099; P = 0.012). Cardiovascular events occurred in 61 patients (13%; 2.4%/year). Multivariable determinants of cardiovascular events were PR interval (HR 1.015, 95% CI 1.005-1.024; P = 0.002) and left ventricular hypertrophy (HR 3.429, 95% CI 1.712-6.868; P = 0.001). Yearly event rate was higher in patients who had developed AF progression, compared to patients without progression [4.9 (2.3-9.0)% vs. 1.9 (1.4-2.6)%; P = 0.006].
Conclusion: Nine of 10 patients with young-onset AF had risk factors and comorbidities, 25% had familial AF. Atrial fibrillation progression to permanent AF and cardiovascular events occurred in 2.0% and 2.4% per year, respectively. Cardiovascular events increased after AF progression had occurred.