Incidence, Prevalence, and Trends in Mortality and Stroke Among Medicare Beneficiaries With Atrial Fibrillation: 2013...

Atrial fibrillation (AF) is known to be associated with increased risks of stroke and death, but contemporary studies of this association are lacking. We evaluated trends in stroke and death among Medicare beneficiaries with AF between 2013 and 2019.

Medicare fee-for-service beneficiaries >65 years old (2011-2019) were included. AF incidence and prevalence were calculated overall and by age group, sex, race, and rurality. Within incident cohorts, the 1-year stroke rate was assessed. Age- and sex-adjusted mortality at 30 days, 1 year, and 3 years was calculated in each incident cohort.

The mean number of Medicare beneficiaries with incident AF per year was 572 630 from 2013 to 2019 (30.44 per 1000 patient-years). The study cohort on average was 79±7.7 years old, 52% female, 88% white, and 83% urban dwelling. Incidence and prevalence of AF increased with age and was highest among White beneficiaries; the incidence was greater in male compared with female beneficiaries. Differences by rurality were not seen. Overall AF prevalence per 1000 beneficiaries increased minimally but steadily from 2013 to 2019 reflecting an increase among male (104-109 per 1000) but not female beneficiaries (82.5 per 1000). The 1-year rate of stroke after incident AF peaked in the 2015 cohort (50.5 per 1000); the rate was at its lowest among the 2018 cohort (41.89 per 1000). Incident AF was associated with mortality that was 3.2× greater than expected at 1 year, but overall mortality and the magnitude of the AF-related mortality risk decreased steadily over time from 22% to 20%.

From 2013 to 2019, AF incidence and prevalence among Medicare beneficiaries were relatively stable but have varied by important demographic subgroups with age and sex remaining powerful risk factors. In contrast, mortality and stroke after incident AF have decreased significantly throughout this era.