HealthDay News — Exposure to air pollution may increase the risk for ischemic stroke in patients with atrial fibrillation (AF), according to a study published online Sept. 15 in JAMA Network Open.
Zachary J. Rhinehart, M.D., from the University of Pittsburgh, and colleagues assessed the association between residential-level pollution exposure in one year and ischemic stroke in individuals with AF. The analysis included 31,414 individuals with AF seen at a large regional health care system (Jan. 1, 2007, through Sept. 30, 2015) in an area with historically high industrial pollution. Follow-up went through Dec. 1, 2017 (median follow-up, 3.5 years).
The researchers found that the mean annual PM2.5 exposure was 10.6 µg/m³. Each standard deviation increase in PM2.5 was associated with a greater risk for stroke when adjusting for demographic and clinical variables (hazard ratio [HR], 1.08; 95 percent confidence interval [CI], 1.03 to 1.14) and when adjusting for neighborhood-level income and educational attainment (HR, 1.07; 95 percent CI, 1.00 to 1.14). Compared with the lowest quartile of PM2.5 exposure, the highest quartile exposure had an increased risk for stroke (HR, 1.36; 95 percent CI, 1.18 to 1.58), which remained after adjusting for clinical covariates, income, and educational level (HR, 1.21; 95 percent CI, 1.01 to 1.45).
“The association between residential-level pollution and stroke risk in the presence of AF appears to be an additional public health toll of pollution and suggests that stroke risk assessment in individuals with AF take into account the contributions of environmental exposures,” the authors write.