Association between temperature and air pollutants with atrial fibrillation presentations to emergency departments.

Introduction: Understanding the impact of environmental exposures on disease incidence is important for environmental guidelines, health services management, and advising patients. We aimed to assess the relationship between daily mean temperature and common pollutants with atrial fibrillation (AF) presentations to emergency departments (EDs).

Methods: The study included consecutive adult patients presenting with AF to EDs from 1/1/2014 to 31/12/2020 with linkage to hospital and emergency discharge diagnosis data. A time series quasi-Poisson regression with a distributed lag nonlinear model was fitted to assess the association between AF with mean air temperature and five common pollutants, overall and according to sex and region, with adjustment for season, day of the week, long-term trend, and co-pollutants.

Results: In 82 575 AF presentations to EDs during the study period, mean (standard deviations [SD]) (SD) age was 69.6 (SD 14.7) years and 50.7% were female. AF presentations were associated with elevated levels of Particulate Matter (PM) 2.5 (≥57.7 µg/m³) and nitrous dioxide (NO2) (≥16.5 parts per billion), but not mean air temperature or other pollutants (carbon monoxide, sulphur dioxide, or ozone). The attributable fraction of AF presentations relating to above optimal NO2 and PM 2.5 levels was 7.24% and 3.81% resulting in 854 and 450 annual excess AF presentations, respectively.

Conclusions: High levels of NO2 and PM 2.5 are associated with increased risk of AF presentations to EDs. These findings have important implications for environmental policies and advice to patients susceptible to AF presentations to EDs, especially in regions with higher baseline levels of PM 2.5 or NO2.