The Epidemic of Atrial Fibrillation

5.1 million Americans may have atrial fibrillation.2

Because atrial fibrillation is the most common type of cardiac arrhythmia, understanding disease trends in the general population is important. Many people are unaware of demographic factors associated with atrial fibrillation:

AF is prevalent in certain populations

Incidence of AF increases due to age

 Incidence of AF increases due to weight

Specific health risks are associated with this heart arrhythmia, and most people are unaware that treatment options are available.

In 2001, a California study on the prevalence and trends of patients diagnosed with atrial fibrillation (AF) in a specific population was published in The Journal of the American Medical Association. The findings from that study have been widely used to estimate the number of Americans affected with atrial fibrillation in a given year. The report concluded that an estimated 2.3 million Americans are currently affected with atrial fibrillation with that number increasing to 5.6 million by 2050.31

A new study conducted in Minnesota by the Mayo Clinic and published in 2006 makes a significant adjustment to the estimated number of Americans affected with atrial fibrillation. The new findings in the study estimate the number of Americans affected with atrial fibrillation at closer to 5.1 million today, and approaching 15.9 million by 2050.2

The conclusive differences between the two studies can be based on a variance in the studied populations. The California study included patients of a health maintenance organization, which is a specific population. The Minnesota study focused on an entire county population in the Midwest. Both studies evaluated patients with electrocardiogram (ECG)-confirmed atrial fibrillation. Therefore, people with atrial fibrillation who could not be confirmed through electrocardiogram testing were not counted in these studies. This means that both estimates are probably very conservative.

Contributing Factors in Prevalence of Atrial Fibrillation

The Minnesota study cites previous underestimates of the increased prevalence of atrial fibrillation due to aging. The Mayo Clinic findings show a 12.6% increase in age-adjusted incidences from 1980 to 2000 in Olmsted County. As estimates of incidence are projected for the future, a 3-fold increase in Americans affected with atrial fibrillation is expected by the year 2050.2

The Minnesota data also points to an increase in incidence of atrial fibrillation among people suffering from obesity. Other studies have shown a relationship between body mass index (BMI) and a predisposition for the development of atrial fibrillation – a 4% increase in AF risk per 1 unit increase in BMI.29 As obesity becomes more prevalent among Americans (increasing from 10% of the Olmsted population in 1980 to 25% of the population in 2002), a relative increase in the incidence of atrial fibrillation is probable.