AMBIENT air pollution is associated with an increased risk of all-cause death, hospital readmission, and burden of all-cause readmissions in patients with heart failure (HF), according to recent research.
Exposure to fine particulate matter (PM2.5), which consists of particles with an aerodynamic diameter of less than 2.5 microns, has been implicated in cardiovascular diseases, particularly in the development of atherosclerosis. Animal studies have suggested that PM2.5 exposure may lead to myocardial fibrosis and an increased risk of HF, therefore, researchers aimed to explore the association between ambient PM2.5 exposure and adverse outcomes in patients with established HF.
The research team analysed data from 2,599,525 patients who were hospitalised for the first time with HF between 2013 and 2020. Patients’ residential zip codes were used to link them with integrated estimates of ambient PM2.5 levels, measured at a fine resolution of 1×1 km. The primary outcomes assessed were all-cause mortality, HF readmission rates, and the overall burden of all-cause hospital readmissions.
The mean PM2.5 level across the study population was 7.3±1.7 μg/m3. The analysis revealed that each interquartile range increase in PM2.5 was associated with a 0.9% higher risk of all-cause death, a 4.5% increase in the hazard of first HF readmission, a 3.1% increase in the risk of HF-related hospitalisation, and a 5.2% increase in the burden of all-cause readmissions. Notably, the adverse effects of PM2.5 were more pronounced at exposure levels below 7 μg/m3 and in specific subgroups, including patients younger than 75 years, Asian individuals, and those living in rural areas.
The findings from this study highlight the significant impact of ambient air pollution on patients with established HF. Even at PM2.5 levels below the National Air Quality Standards (12 μg/m3), the association with adverse outcomes persists, suggesting that there is no safe threshold for PM2.5 exposure in this vulnerable population. These results highlight the importance of considering environmental factors in the management and follow-up of HF patients to improve outcomes and reduce hospital readmissions.
Katrina Thornber, EMJ
Reference
Mentias A et al. Ambient air pollution exposure and adverse outcomes among medicare beneficiaries with heart failure. J Am Heart Assoc. 2024;13(15):e032902.
