Ischemic Heart Disease Events Triggered by Short-Term Exposure to Fine Particulate Air Pollution

TLDR

Recent evidence links long‑term particulate air pollution to oxidative stress, inflammation, atherosclerosis, and ischemic heart disease, while short‑term exposure may trigger plaque vulnerability and acute events, though findings remain inconclusive. This study evaluates the role of short‑term particulate exposure in triggering acute ischemic heart disease events. A case‑crossover study of 12,865 Utah residents from the Intermountain Heart Collaborative cardiac catheterization registry examined ischemic events. A 10 µg/m³ increase in PM₂.₅ was associated with a 4.5 % rise in acute coronary events (unstable angina and MI), with larger effects in patients with angiographically confirmed coronary artery disease, while those with stable disease or clean coronaries were less susceptible.

Abstract

Background— Recent evidence suggests that long-term exposure to particulate air pollution contributes to pulmonary and systemic oxidative stress, inflammation, progression of atherosclerosis, and risk of ischemic heart disease and death. Short-term exposure may contribute to complications of atherosclerosis, such as plaque vulnerability, thrombosis, and acute ischemic events. These findings are inconclusive and controversial and require further study. This study evaluates the role of short-term particulate exposure in triggering acute ischemic heart disease events. Methods and Results— A case-crossover study design was used to analyze ischemic events in 12 865 patients who lived on the Wasatch Front in Utah. Patients were drawn from the cardiac catheterization registry of the Intermountain Heart Collaborative Study, a large, ongoing registry of patients who underwent coronary arteriography and were followed up longitudinally. Ambient fine particulate pollution (particles with an aerodynamic diameter ≤2.5 μm; PM 2.5 ) elevated by 10 μg/m 3 was associated with increased risk of acute ischemic coronary events (unstable angina and myocardial infarction) equal to 4.5% (95% confidence interval, 1.1 to 8.0). Effects were larger for those with angiographically demonstrated coronary artery disease. Conclusions— Short-term particulate exposures contributed to acute coronary events, especially among patients with underlying coronary artery disease. Individuals with stable presentation and those with angiographically demonstrated clean coronaries are not as susceptible to short-term particulate exposure.