Ambient air pollution is associated with increased risk of hospital cardiac readmissions of myocardial infarction survivors in five European cities.
BACKGROUND
Ambient air pollution has been associated with increases in acute morbidity and mortality. The objective of this study was to evaluate the short-term effects of urban air pollution on cardiac hospital readmissions in survivors of myocardial infarction, a potentially susceptible subpopulation.


RESULTS
In this European multicenter cohort study, 22,006 survivors of a first myocardial infarction were recruited in Augsburg, Germany; Barcelona, Spain; Helsinki, Finland; Rome, Italy; and Stockholm, Sweden, from 1992 to 2000. Hospital readmissions were recorded in 1992 to 2001. Ambient nitrogen dioxide, carbon monoxide, ozone, and mass of particles <10 microm (PM10) were measured. Particle number concentrations were estimated as a proxy for ultrafine particles. Short-term effects of air pollution on hospital readmissions for myocardial infarction, angina pectoris, and cardiac causes (myocardial infarction, angina pectoris, dysrhythmia, or heart failure) were studied in city-specific Poisson regression analyses with subsequent pooling. During follow-up, 6655 cardiac readmissions were observed. Cardiac readmissions increased in association with same-day concentrations of PM10 (rate ratio [RR] 1.021, 95% CI 1.004 to 1.039) per 10 microg/m3) and estimated particle number concentrations (RR 1.026 [95% CI 1.005 to 1.048] per 10,000 particles/cm3). Effects of similar strength were observed for carbon monoxide (RR 1.014 [95% CI 1.001 to 1.026] per 200 microg/m3 [0.172 ppm]), nitrogen dioxide (RR 1.032 [95% CI 1.013 to 1.051] per 8 microg/m3 [4.16 ppb]), and ozone (RR 1.026 [95% CI 1.001 to 1.051] per 15 microg/m3 [7.5 ppb]). Pooled effect estimates for angina pectoris and myocardial infarction readmissions were comparable.


CONCLUSIONS
The results suggest that ambient air pollution is associated with increased risk of hospital cardiac readmissions of myocardial infarction survivors in 5 European cities.
von Klot
Stephanie
S
Institute of Epidemiology, GSF-National Research Center for Environment and Health, Neuherberg, Germany. klot@gsf.de
Peters
Annette
A
Aalto
Pasi
P
Bellander
Tom
T
Berglind
Niklas
N
D'Ippoliti
Daniela
D
Elosua
Roberto
R
Hörmann
Allmut
A
Kulmala
Markku
M
Lanki
Timo
T
Löwel
Hannelore
H
Pekkanen
Juha
J
Picciotto
Sally
S
Sunyer
Jordi
J
Forastiere
Francesco
F
D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D000787:Angina Pectoris / Q000453:epidemiology; D002248:Carbon Monoxide / Q000009:adverse effects; D005060:Europe / Q000453:epidemiology; D049671:History, 18th Century; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology*; D009585:Nitrogen Dioxide / Q000009:adverse effects; D010126:Ozone / Q000009:adverse effects / Q000032:analysis; D010359:Patient Readmission / Q000706:statistics & numerical data*; D016012:Poisson Distribution; D012044:Regression Analysis; D012307:Risk Factors; D017741:Survivors
D000393:Air Pollutants; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide