TOPLINE:

Chronic exposure to fine particulate matter with an aerodynamic diameter ≤ 2.5 and ≤ 10 µm (PM_2.5 and PM₁₀, respectively) was associated with elevated cardiac magnetic resonance (CMR) markers of early myocardial fibrosis in patients with structurally normal hearts, according to a retrospective analysis.

METHODOLOGY:

• Researchers conducted a single-centre retrospective study at IRCCS Humanitas Research Hospital, Milan, Italy, and screened 231 consecutive patients (mean age, 45.1 years; 53% men) with structurally normal hearts and no late gadolinium enhancement who underwent clinically indicated CMR between May 2020 and November 2024.
• They analysed exposure to airborne PM_2.5 and PM₁₀ in the year preceding CMR, deriving annual average 24-hour pollutant levels from the nearest European Environment Agency monitoring stations to the residence of the patients.
• CMR morphofunctional and tissue characterisation followed a standardised protocol on a 1.5T scanner, with synthetic extracellular volume (ECV) calculated using a validated approach without blood sampling.
• Outcomes included associations between pollutant exposure and continuous CMR morphofunctional and tissue parameters including native T1 mapping values, T2 mapping values, and synthetic ECV after adjustment for demographic, clinical, and socioeconomic factors and inflammatory markers.

TAKEAWAY:

• An increase in exposure to PM_2.5 was associated with higher native T1 mapping values (P = .012) and synthetic ECV (P = .023), suggesting early diffuse myocardial fibrosis.
• An increase in exposure to PM₁₀ was associated with higher synthetic ECV (P = .001), but no significant association was observed with native T1 values or other CMR parameters including T2 mapping.
• Each 1 μg/m³ increase in PM_2.5 was associated with increased odds of elevated native T1 values (odds ratio [OR], 1.16; P =.020) and elevated synthetic ECV (OR, 1.06; P = .004); however, exposure to PM₁₀ was not a significant predictor of increased native T1 values or synthetic ECV.
• The association between PM_2.5 and native T1 was more pronounced in men (P = .017), and the association between PM₁₀ and synthetic ECV was stronger in men (P = .007) and patients aged 50 years or older (P = .018).

IN PRACTICE:

"[The study] findings suggest an association between PM exposure and subtle CMR changes consistent with early myocardial fibrosis, which should be confirmed in larger prospective studies," the authors wrote.

SOURCE:

This study was led by Stefano Figliozzi, MD, and Gaia Filiberti, MD, IRCCS Humanitas Research Hospital, Milan, Italy. It was published online on March 17, 2026, in European Heart Journal - Cardiovascular Imaging.

LIMITATIONS:

The retrospective single-centre design with a relatively small sample size limited generalisability and precluded causal inference. Exposure was estimated from residential proximity to air quality monitors over 1 year, which may not have reflected individual variability. Diffuse fibrosis was assessed by native T1 mapping and synthetic ECV without histologic confirmation. Limited inflammatory biomarker data may have reduced power for mediation and interaction analyses. The study population was derived from clinically referred CMR examinations rather than the general population, which may have introduced selection bias and further limited external validity.

DISCLOSURES:

No funding sources were provided for the study. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.