Modeling of the relationship between the environmental air pollution, clinical risk factors, and hospital mortality due to myocardial infarction in Isfahan, Iran

Th is study aimed to determine the relationship between the environmental factor, clinical risk factors, and individual variables with mortality due to acute myocardial infarction (MI) in Isfahan. Th is cross-sectional study was performed between April 2012 and March 2013. Th e data on the patients’ mortality due to MI in Isfahan were obtained from the MI National Registry. Th e international classifi cation system (ICD10: I21-I22) was used to diagnose MI. Th e air quality indicators and environmental variables were used to measure the air pollution. Multilevel logistic regression in the Stata software was used to determine the factors associated with mortality in patients and odds ratios (ORs) were calculated. Six hundred eleven patients with MI were studied during 1-year. 444 (72.2%) patients were male and the rest were female. 4.7% of the patients died due to MI. Th e mean age at MI incidence was 62.2 ± 13 years. Of the air pollution parameters, PM10 had the maximum mean concentration (49.113 ppm), followed by NOX, NO, NO2, CO, SO2, and O3. Th e adjusted OR of mortality was derived 2.07 (95% CI: 1.5-2.85) for right bundle branch block, 1.5 (95% CI: 1.3-1.7) for ST-segment elevation MI, 1.84 (95 CI: 1.13-3) for age, 1.06 (95% CI: 1.01-1.20) for CO, 1.1 (95% CI: 1.03-1.30) for O3, and 1.04 (95% CI: 1.01-1.4) for SO2, all of which were considered as the risk factors of mortality. However, OR of mortality was 0.79 for precipitation (95% CI: 0.74-0.84) and 0.52 for angioplasty (95% CI: 0.4-0.68) were considered as protective factors of mortality. Th e individual characteristics including age, history of MI in the immediate family, hypertension, and diabetes were signifi cantly associated with mortality from MI. Th e indices of air pollution including SO2, CO, O3, and environmental factors such as the precipitation and temperature were the determinants of mortality in patients with MI. With regards to the factors associated with mortality from MI reported in this study, air pollution and environmental factors, in addition to the risk factors and predictive factors, should be particularly addressed to control the mortality from MI.