Sex-Specific Associations between Long-term Air Pollution Exposure and Coronary Atherosclerosis at Cardiac CT

Background Air pollution is the leading environmental risk factor for cardiovascular disease. However, data regarding its association with coronary artery disease (CAD) beyond coronary artery calcium score (CACS) remain limited. Purpose To evaluate the relationship between long-term exposure to particulate and gaseous air pollutants and CT markers of CAD stratified by sex. Materials and Methods Adult patients who underwent outpatient cardiac CT for CAD evaluation between January 2012 and December 2023 were included in this multisite retrospective study. CACS, total plaque burden, and presence of obstructive CAD (≥70% diameter stenosis) were evaluated. Mean exposure to fine particulate matter (particulate matter measuring ≤2.5 µm in diameter [PM_2.5]) and NO₂ air pollution was assessed over the 10-year period before cardiac CT. Negative binomial (CACS), ordinal logistic (plaque burden), and logistic (obstructive CAD) regression models were constructed and adjusted for clinically relevant covariates. Results Overall, 11 128 patients who underwent cardiac CT were included (mean age, 59.1 years ± 11.3 [SD]; 5754 [51.7%] men), among whom 7313 patients (mean age, 59.5 years ± 11.5; 3561 [48.7%] men) underwent coronary CT angiography. The median 10-year exposure was 7.5 μg/m³ (range, 4.3-9.2 μg/m³) for PM_2.5 and 13.4 parts per billion (ppb) (range, 3.2-17.8 ppb) for NO₂. Greater PM_2.5 and NO₂ exposures were associated with greater CACS (PM_2.5: incidence rate ratio (IRR) = 1.11, P < .001; NO₂: IRR = 1.01, P = .04) and total plaque burden (PM_2.5: odds ratio [OR] = 1.13, P = .02; NO₂: OR = 1.04, P < .001) according to multivariable analysis. In maximally adjusted models stratified by sex, long-term air pollution exposure was associated with obstructive CAD in women (PM_2.5: OR = 1.81, P = .048; NO₂: OR = 1.06, P = .04); however, there was no evidence of an association in men (PM_2.5: OR = 1.14, P = .38; NO₂: OR = 1.03, P = .13). Conclusion Long-term exposure to PM_2.5 and NO₂ is independently associated with more advanced coronary atherosclerosis at cardiac CT, even at moderate contemporary exposure levels. © RSNA, 2026.