Ten-year trends in incidence and prevalence of atrial fibrillation and flutter in Denmark according to demographics, ethnicity, educational level, and area of residence (2009-2018).

Background: Atrial fibrillation is the most common cardiac arrhythmia and a major global health burden. Updated trends in the epidemiology of atrial fibrillation or flutter (AF) are needed.

Methods: Using the Danish Heart Statistics, we investigated nationwide trends 2009-2018 in incidence rate and prevalence of AF according to age as well as age-standardized incidence rate (ASIR) and prevalence (ASP) of AF according to sex, ethnicity, educational level, and area of residence. Comparing year 2018 to 2009, we calculated stratum-specific ASIR ratios (ASIRR) and changes in ASP.

Results: During 2009-2015 the ASIR for AF increased for both men and women, followed by a decline from 2015-2018. Overall, this resulted in a 9% increase among men (ASIRR: 1.09, 95% CI: 1.06-1.12), but no change among women (ASIRR: 1.00, 95% CI: 0.97-1.04). The ASP increased by 29% among men and 26% among women. An increase in ASIR was observed in all ethnic groups except men of Far Eastern ethnicity. Lower educational level was associated with greater increases in both ASIR and ASP. ASIR and ASP differed slightly between the Danish regions but increased in all of them.

Conclusions: During 2009-2018 the incidence and prevalence of AF in Denmark increased although the increase in incidence was transient among women. Factors associated with higher incidence were male sex, higher age, Danish and Western ethnicity as well as Middle Eastern/North African ethnicity among women, and lower educational level. Within Denmark, we observed only minor regional differences in AF incidence and prevalence.