Global Association of Air Pollution and Heart Failure: A Systematic Review and Meta-Analysis

Study Questions:

What is the association between air pollution and acute decompensated heart failure, including hospitalization and heart failure mortality?


Five databases were searched for studies investigating the association between daily increases in gaseous (carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone) and particulate (diameter <2.5 μm [PM2.5] or <10 μm [PM10]) air pollutants, and heart failure hospitalizations or heart failure mortality. The investigators used a random-effects model to derive overall risk estimates per pollutant.


Of 1,146 identified articles, 195 were reviewed in-depth, with 35 satisfying inclusion criteria. Heart failure hospitalization or death was associated with increases in carbon monoxide (3.52% per 1 part per million; 95% confidence interval [CI], 2.52-4.54), sulphur dioxide (2.36% per 10 parts per billion; 1.35-3.38), and nitrogen dioxide (1.70% per 10 parts per billion; 1.25-2.16), but not ozone (0.46% per 10 parts per billion; −0.10 to 1.02) concentrations. Increases in particulate matter concentration were associated with heart failure hospitalization or death (PM2.5 2.12% per 10 μg/m3; 95% CI, 1.42-2.82; PM10 1.63% per 10 μg/m3; 95% CI, 1.20-2.07). Strongest associations were seen on the day of exposure, with more persistent effects for PM2.5. In the United States, investigators estimate that a mean reduction in PM2.5 of 3.9 μg/m3 would prevent 7,978 heart failure hospitalizations and save one third of a billion US dollars a year.


The authors concluded that air pollution has a close temporal association with heart failure hospitalization and heart failure mortality.


This study reported robust temporal associations between exposure to air pollutants and heart failure hospitalizations and mortality. The magnitude and direction of the overall estimates persisted despite conservative modeling. Although causality and understanding of biological mechanisms need additional research, air pollution is a pervasive public health issue with major cardiovascular and health care economic consequences. In light of the current study findings, control of air pollution should be pursued by all necessary means, including use of legislation. Furthermore, the United States should lower their regulatory limits for particulate matter concentrations, which are presently above the World Health Organization’s recommendations, since even small reductions may confer substantial population health benefits.

Clinical Topics: Heart Failure and Cardiomyopathies, Acute Heart Failure

Keywords: Particulate Matter, Nitrogen Dioxide, World Health Organization, Sulfur Dioxide, Ozone, Cardiology, Heart Failure, Carbon Monoxide, Cardiovascular Diseases, United States

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