Context Atrial fibrillation is the most common arrhythmia in elderly persons
and a potent risk factor for stroke. However, recent prevalence and projected
future numbers of persons with atrial fibrillation are not well described.
Objective To estimate prevalence of atrial fibrillation and US national projections
of the numbers of persons with atrial fibrillation through the year 2050.
Design, Setting, and Patients Cross-sectional study of adults aged 20 years or older who were enrolled
in a large health maintenance organization in California and who had atrial
fibrillation diagnosed between July 1, 1996, and December 31, 1997.
Main Outcome Measures Prevalence of atrial fibrillation in the study population of 1.89 million;
projected number of persons in the United States with atrial fibrillation
Results A total of 17 974 adults with diagnosed atrial fibrillation were
identified during the study period; 45% were aged 75 years or older. The prevalence
of atrial fibrillation was 0.95% (95% confidence interval, 0.94%-0.96%). Atrial
fibrillation was more common in men than in women (1.1% vs 0.8%; P<.001). Prevalence increased from 0.1% among adults younger than
55 years to 9.0% in persons aged 80 years or older. Among persons aged 50
years or older, prevalence of atrial fibrillation was higher in whites than
in blacks (2.2% vs 1.5%; P<.001). We estimate
approximately 2.3 million US adults currently have atrial fibrillation. We
project that this will increase to more than 5.6 million (lower bound, 5.0;
upper bound, 6.3) by the year 2050, with more than 50% of affected individuals
aged 80 years or older.
Conclusions Our study confirms that atrial fibrillation is common among older adults
and provides a contemporary basis for estimates of prevalence in the United
States. The number of patients with atrial fibrillation is likely to increase
2.5-fold during the next 50 years, reflecting the growing proportion of elderly
individuals. Coordinated efforts are needed to face the increasing challenge
of optimal stroke prevention and rhythm management in patients with atrial