BackgroundStudies have shown that long‐term exposure to air pollution such as fine particulate matter (≤2.5 μm in aerodynamic diameter [PM 2.5]) increases the risk of all‐cause and cardiovascular mortality. To date, however, there are limited data on the impact of air pollution on specific cardiovascular diseases. This study aimed to evaluate cardiovascular effects of long‐term exposure to air pollution among residents of Seoul, Korea.Methods and ResultsHealthy participants with no previous history of cardiovascular disease were evaluated between 2007 and 2013. Exposure to air pollutants was estimated by linking the location of outdoor monitors to the ZIP code of each participant's residence. Crude and adjusted analyses were performed using Cox regression models to evaluate the risk for composite cardiovascular events including cardiovascular mortality, acute myocardial infarction, congestive heart failure, and stroke. A total of 136 094 participants were followed for a median of 7.0 years (900 845 person‐years). The risk of major cardiovascular events increased with higher mean concentrations of PM 2.5 in a linear relationship, with a hazard ratio of 1.36 (95% confidence interval, 1.29–1.43) per 1 μg/m3 PM 2.5. Other pollutants including PM 2.5–10 of CO, SO 2, and NO 2, but not O3, were significantly associated with increased risk of cardiovascular events. The burden from air pollution was comparable to that from hypertension and diabetes mellitus.ConclusionsThis large‐scale population‐based study demonstrated that long‐term exposure to air pollution including PM 2.5 increases the risk of major cardiovascular disease and mortality. Air pollution should be considered an important modifiable environmental cardiovascular risk factor.

Aim: Arterial stiffness assessed by brachial-ankle pulse wave velocity (baPWV) is predictive of cardiovascular events. This study was designed to investigate whether baPWV has an additional prognostic value to single-photon emission computed tomography (SPECT) in patients with suspected coronary artery disease (CAD). Methods: A total of 350 subjects (age, 66.2 10.5 years, 53.4% male) with suspected CAD undergoing myocardial SPECT and baPWV within 30 days were retrospectively analyzed. Cardiovascular events, including cardiovascular death, acute coronary syndrome and ischemic stroke, were assessed. Both fixed and reversible perfusion defects on SPECT were considered abnormal myocardial perfusion imaging (MPI) findings. Results: During the median follow-up period of 441 days (interquartile range 169 -719 days), cardiovascular events occurred in 21 patients (6.0%). In multivariable Cox regression analysis, abnormal MPI [hazard ratio (HR), 2.67; 95% confidence interval (CI), 1.21 -10.37; p 0.024] and high baPWV ( ≥1,790 cm/s) (HR, 2.03; 95% CI, 1.08 -6.38; p 0.007) were independent predictors of clinical events even after adjusting for possible confounders. Also, high baPWV had an incremental prognostic value to traditional risk factors and abnormal MPI in predicting cardiovascular events (overall Chi-square, from 24.08 to 27.42; p 0.001). Kaplan -Meier survival curves stratified by baPWV and MPI proved significantly improved prediction of cardiovascular events (log-rank p 0.001). Conclusions: baPWV has an incremental prognostic value to traditional risk factors and MPI. Therefore, baPWV can be used to identify subjects at higher risk of cardiovascular events in patients undergoing SPECT.