Mortality, Hospitalization, and Cardiac Interventions in Patients With Atrial Fibrillation Aged <65 Years.

BACKGROUND: The risk factor (RF) burden, clinical course, and long-term outcome among patients with atrial fibrillation (AF) aged <65 years is unclear. METHODS: Adult (n=67 221; mean age, 72.4±12.3 years; and 45% women) patients with AF evaluated at the University of Pittsburgh Medical Center between January 2010 and December 2019 were studied. Hospital system-wide electronic health records and administrative data were utilized to ascertain RFs, comorbidities, and subsequent hospitalization and cardiac interventions. The association of AF with all-cause mortality among those aged <65 years was analyzed using an internal contemporary cohort of patients without AF (n=918 073). RESULTS: Nearly one-quarter (n=17 335) of the cohort was aged <65 years (32% women) with considerable cardiovascular RFs (current smoker, 16%; mean body mass index, 33.0±8.3; hypertension, 55%; diabetes, 21%; heart failure, 20%; coronary artery disease, 19%; and prior ischemic stroke, 6%) and comorbidity burden (chronic obstructive pulmonary disease, 11%; obstructive sleep apnea, 18%; and chronic kidney disease, 1.3%). Over mean follow-up of >5 years, 2084 (6.7%, <50 years; 13%, 50-65 years) patients died. The proportion of patients with >1 hospitalization for myocardial infarction, heart failure, and stroke was 1.3%, 4.8%, and 1.1% for those aged <50 years and 2.2%, 7.4%, and 1.1% for the 50- to 65-year subgroup, respectively. Multiple cardiac and noncardiac RFs were associated with increased mortality in younger patients with AF with heart failure and hypertension demonstrating significant age-related interaction (P=0.007 and P=0.013, respectively). Patients with AF aged <65 years experienced significantly worse survival compared with comorbidity-adjusted patients without AF (men aged <50 years and hazard ratio, 1.5 [95% CI, 1.24-1.79]; 50-65 years and hazard ratio, 1.3 [95% CI, 1.26-1.43]; women aged <50 years and hazard ratio, 2.4 [95% CI, 1.82-3.16]; 50-65 years and hazard ratio, 1.7 [95% CI, 1.6-1.92]). CONCLUSIONS: Patients with AF aged <65 years have significant comorbidity burden and considerable long-term mortality. They are also at a significantly increased risk of hospitalization for heart failure, stroke, and myocardial infarction. These patients warrant an aggressive focus on RF and comorbidity evaluation and management.