Abstract 11876: Air Pollution and Myocardial Infarction: A Systematic Review and Meta-Analysis
Introduction: The association between air pollution and myocardial infarction (MI) remains controversial. Some studies illustrated an increased risk of MI whereas other studies showed no significant effect. The common air-pollutants are ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter within 10 µm (PM10) and particulate matter within 2.5 µm (PM2.5).
Hypothesis: We hypothesized that air pollution is associated with an increased risk of MI.
Methods: We conducted a systematic review and first meta-analysis searching in several databases to identify studies that evaluated the risk of MI related to air pollution, through March 2011, in any language. Two independent reviewers determined studies eligibility and extracted methodological and outcome data. The relative risks (RRs) were pooled across studies using random-effects model. The I2 statistic and Egger's test were used to respectively assess heterogeneity and publication bias.
Results: 33 studies were included, consisting of 18 time-series and 15 case-crossover studies. All common air-pollutants, except O3 were significantly associated with MI. The pooled RR were 1.058 [1.030-1.087], I2=93% for CO, 1.012 [1.006-1.017], I2=70% for NO2, 1.012 [1.004-1.020], I2=67% for SO2, 1.007 [1.004-1.011], I2=51% for PM10, 1.025 [1.015-1.036], I2=52% for PM2.5 and 1.003 [0.996-1.010], I2=84% for O3.Sensitivity analyses showed a similar effect size while reducing the heterogeneity. Moreover, no statistical argument for publication bias was found. Population attributable fractions, depending on the pollutant, were between 0.7 to 5.5%.
Conclusions: Despite the low levels of relative risks, the high frequency of exposure to air pollution corresponds to an elevated population attributable fraction and therefore, may have considerable public health implications.
- © 2011 by American Heart Association, Inc.