Cardiac CT links air pollution to increased risk of coronary disease
Long-term exposure to air pollution is associated with more advanced coronary atherosclerosis, including greater plaque burden and obstructive coronary artery disease, according to a large cardiac CT study published in Radiology.[1]
Researchers led by Kate Hanneman, MD, MPH, associate professor and vice chair of research in the department of medical imaging at the University of Toronto, analyzed cardiac CT data from 11,128 adults who underwent clinical scans at three Toronto hospitals between 2012 and 2023. The study linked patients’ residential postal codes with air-quality data to estimate their average exposure to pollution during the 10 years before their CT examinations.
"What we found is that higher air pollution exposure, both gaseous and particulate, was associated with higher coronary calcium scores, higher plaque burden, and obstructive coronary disease in unadjusted models," Hanneman explained a video interview with Cardiovascular Business at SCCT2026, the Society of Cardiovascular Computed Tomography (SCCT) annual meeting. "When we adjusted for age, sex, and traditional cardiovascular risk factors, we found that in women, higher air pollution was also associated with obstructive disease, even in these multi-variable models. So this really builds on the existing literature that tells us that higher air pollution is not good for us and it's not good for our heart."
The investigators focused on two common urban pollutants: fine particulate matter (PM2.5) and nitrogen dioxide (NO2). PM2.5 can come from vehicle exhaust, industrial emissions and wildfire smoke, while NO2 is produced primarily by fossil-fuel combustion from vehicles, power plants and industry.
Cardiac CT enabled the researchers to evaluate three measures of coronary disease: coronary calcium, total plaque burden and obstructive stenosis. For every 1 microgram-per-cubic-meter increase in long-term PM2.5 exposure, coronary calcium increased by 11%, while the odds of having greater plaque burden increased by 13% and the odds of obstructive coronary disease increased by 23%. NO2 exposure showed similar associations, although the effects were smaller.
“This is one of the largest studies to use cardiac CT to show that air pollution is linked to more advanced coronary artery disease,” Hanneman said, noting that the study went beyond calcium scoring to assess total plaque and obstructive disease.
The associations remained important after accounting for traditional cardiovascular risk factors. Hanneman said the study found clear associations between higher pollution exposure and calcium scores and plaque burden in both men and women. In adjusted analyses, higher pollution exposure was also associated with obstructive disease in women. She cautioned that the sex-specific findings are hypothesis-generating and require further study.
These findings could eventually influence cardiovascular risk assessment by adding environmental exposure history to factors such as smoking, blood pressure, cholesterol and family history. Hanneman said cardiac CT is particularly useful for environmental health research because it can directly visualize and quantify coronary atherosclerosis.
Prevention, however, extends beyond clinical care. Hanneman emphasized that reducing air pollution requires policy and urban-planning changes, but individuals can take steps to reduce exposure during periods of poor air quality, including wildfire smoke. Using HEPA filtration, keeping windows closed and avoiding outdoor exercise when air quality is poor can reduce exposure. She also recommended using ventilation when cooking with a gas stove.
The study adds to evidence linking both short- and long-term air pollution exposure with cardiovascular disease and suggests that cardiac CT may provide a way to visualize the effects of environmental exposure before cardiovascular events occur.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: [email protected]