Air pollution warning for patients with heart disease

It is known that people suffering from conditions such as heart disease tend to suffer during spikes in air pollution, but new research shows that for those people, cardiac inflammation levels actually rise during particularly bad air quality episodes.

Researchers at Intermountain Health in Salt Lake City presented their findings on Saturday at the American Heart Association’s 2024 Scientific Sessions international conference in Chicago.

The team looked at blood tests for 115 different proteins that are signs of increased inflammation in the body.

They worked with scientists at Stanford University and the Harvard School of Public Health to examine the blood of patients enrolled in the Intermountain INSPIRE registry, which collects blood and other biological samples, medical information and laboratory data from healthy individuals and those who have been diagnosed with a variety of medical conditions.

They tested blood samples of 44 patients suffering from heart failure with preserved ejection fraction (where the heart pumps normally but is too stiff to fill properly) and 35 people without heart disease.

Some blood samples were taken on days with low air pollution, where ambient PM2.5 levels were below 7μg/m³ and these were compared to samples taken from other people on days when PM2.5 levels reached 20μg/m³ or over.

These air pollution episodes were caused by either wildfire smoke in the summer, or during a winter inversion, where air pollution is trapped when warm air holds pollution closer to the ground.

They found that two inflammatory markers were elevated in heart failure patients who were exposed to poor air quality, but did not change in those without heart disease, suggesting that air pollution events – in these cases wildfire smoke in the summer or  temperature inversions during the winter – put more strain on the bodies of patients who already have heart problems.

Benjamin Horne, PhD, principal investigator of the study and professor of research at Intermountain Health. said: ‘These biomarkers rose in response to air pollution in people who already had heart disease, but not in patients who were heart disease free, showing that heart failure patients are not as able to adapt to changes in the environment.

‘These findings give us some information about mechanisms in people with heart failure who are having inflammation and suggest they’re not as capable in responding to acute inflammation as people who are healthy.

‘It’s important that individuals with known heart disease, including those diagnosed with heart failure, need to be especially cautious during periods of poor air quality. This includes exercising indoors, making sure to take their prescribed medications, and avoiding areas like roadways and highways where there’s a lot more traffic and pollution.’