Study Links Air Pollution to Increased Myocardial Fibrosis in Patients

A recent study published in the journal *Radiology* has established a significant correlation between air pollution exposure and the prevalence of diffuse myocardial fibrosis, particularly among individuals with dilated cardiomyopathy (DCM) and those with initially normal cardiac MRI results. The study, involving 694 patients with a mean age of 47, revealed that each 1 µg/m³ increase in one-year exposure to ambient fine particulate matter (PM2.5) was associated with a remarkable 30% increase in the native T1 z score in patients with DCM and a 27% increase in those with normal cardiac MRI findings.

The research emphasizes that air pollution may be a modifiable risk factor for cardiovascular disease, as noted by Dr. Kate Hanneman, M.D., MPH, FRCPC, an associate professor and vice chair of research at the Department of Medical Imaging at the University of Toronto. Dr. Hanneman indicated, "Our results reinforce that there are no safe exposure limits for fine particulate air pollution, as adverse effects are observable at levels below current air quality guidelines."

The study's methodology involved a retrospective analysis of cardiac MRI data, highlighting the increasing concern over air quality and its implications for public health. The findings indicate that the likelihood of late gadolinium enhancement (LGE) in patients with DCM increased by 25% with each 1 µg/m³ rise in PM2.5 exposure.

The study also identified vulnerable subgroups, with stronger associations observed among women (49% increase in native T1 z scores), individuals with hypertension (48%), and smokers (43%). These results align with previous research suggesting that myocardial fibrosis, once established, is irreversible and necessitates urgent public health measures to mitigate long-term air pollution exposure.

Despite the compelling findings, the authors acknowledged the inherent limitations of the single-center retrospective design, including potential confounding factors and the exclusion of indoor PM2.5, ozone, and nitrogen dioxide exposures from the analysis. The COVID-19 pandemic's impact during the study period was also considered as a variable that could influence results.

Dr. Davis M. Vigneault, M.D., D.Phil, from the Department of Radiology at Stanford University, commented on the study's implications, stating it builds upon existing biochemical and epidemiological evidence linking air pollution to cardiovascular risks. He noted, "This research provides new insights into the mechanisms by which fine particulate matter may induce myocardial fibrosis, establishing a connection between environmental factors and cardiovascular health outcomes."

As urban areas continue to grapple with air quality issues, these findings underscore the urgent need for comprehensive public health strategies aimed at reducing air pollution and protecting vulnerable populations.