Short-term associations between ambient air pollution and acute atrial fibrillation episodes

Atrial fibrillation (AF), prevalent in approximately 1-3% of the population, is associated with a higher risk of stroke, dementia, mortality, and a reduced quality of life. Air pollution may be associated with heart rhythm disturbances, but there is limited evidence regarding whether short-term changes in air pollution levels are associated with acute onset of AF episodes.

We screened 8,899 randomly selected 75-yearolds living in Stockholm without previously known AF for AF using home-based short-term ambulatory 1-lead ECG-measurements 2-4 times a day for 14 days. Screenings were carried out in 2012-2013 and 2016-2018. We used generalized estimating equations to quantify the association between PM_2.5, PM₁₀, NO₂ and O₃ obtained from a fixed monitoring station and risk of AF onset among participants with AF observed during the screening period, adjusting for temperature, relative humidity and temporal factors. We explored potential susceptible subgroups.

Among 218 participants with 469 AF episodes we observed higher odds of AF following higher 24-hour mean levels of PM₁₀ and O₃, reaching statistical significance for PM₁₀ levels averaged over the previous 12-24-hours [OR 1.10 (95%CI 1.01-1.19) per IQR of PM₁₀ (7.8 µg/m³)]. In subgroup analyses, PM_2.5 was more strongly associated with AF among participants with hypertension and PM₁₀ and O₃ were more strongly associated with AF among participants with diabetes and overweight.

These results suggest that in an urban setting with relatively low levels of ambient air pollution, hourly changes in pollutant levels may increase the risk of acute episodes of both asymptomatic and symptomatic AF, especially among people with diabetes, hypertension or overweight.