REYKJAVIK, ICELAND. There seems to be no question that the incidence (new cases per 1000 person-years) and prevalence (% of a given population having AF at any given point in time) of atrial fibrillation (AF) is on the rise, at least in first world countries. American researchers believe that between 2.3 million and 5.1 million Americans were suffering from AF in the year 2000, and that this number could rise to 5.6 million or even 15.9 million in 2050. A recent major study involving 21 million Americans concluded that 3 million people in the USA were struggling with AF in 2005 and that this number would rise to 7.6 million by 2050. Chinese researchers have estimated that 8 million Chinese suffer from AF with 22% of cases being classified as lone AF. A Dutch study involving 6400 citizens of Rotterdam found an overall prevalence of AF of 5.5% in 1990 increasing to 8.3% by January 2000.

Now a team of researchers from the National University Hospital of Iceland reports that the incidence and prevalence of AF is also increasing dramatically in Iceland (2008 population of 229,000). During the period 1991 to 2008 the age- and sex-standardized incidence of AF increased from 2.1% to 2.4% (as determined from AF-related admissions to hospital, emergency rooms, and outpatient clinics). The age- and sex-standardized prevalence of AF rose from 1.5% to 1.9% in the period 1998 to 2008 (2.3% for men and 1.5% for women). The prevalence increase was most pronounce (5.1%) in men aged 85 to 99 years. Taking into account increases in life expectancy and population, it is estimated that the prevalence of AF will rise from 2.0% in 2008 to 3.0% in 2020, and 4.3% in 2050. This corresponds to an increase of over 200% in the number of adult Icelanders having AF by 2050.

Applying the numbers for Iceland to all of Europe would lead to the conclusion that about 10 million Europeans currently have AF and that by 2050 this number could rise to a staggering 25 to 30 million � clearly a very serious burden on health care systems. By far, the majority (probably around 80%) of AF cases are associated with comorbid conditions such as hypertension, heart disease, diabetes, and obesity. In an accompanying editorial, Danish and British cardiologists suggest that the way to stem the AF epidemic is an increased emphasis on prevention of the above modifiable risk factors through exercise and diet changes.

Stefansdottir, H, Arnar, DO, et al. Trends in the incidence and prevalence of atrial fibrillation in Iceland and future projections. Europace, Vol. 13, 2001, pp. 1110-17 Olesen, JB, et al. An epidemic of atrial fibrillation? Europace, Vol. 13, 2001, pp. 1059-60

Editor�s comment: This newest estimate of the present and expected AF burden in Europe is indeed sobering and most likely underestimated. Although two-thirds of the population of Iceland lives in Reykjavik and there is only one hospital there, it is highly likely that some cases of AF were missed either because they were asymptomatic or because they were managed by general practitioners without involving hospital admissions.