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2015 Conference

Abstract Number: 456 | ID: 2015-456

Long-Term Exposure To Traffic-Related Air Pollution And All-Cause Mortality After Myocardial Infarction

Gali Cohen - Department Of Epidemiology And Preventive Medicine, School Of Public Health, Sackler Faculty Of Medicine, Tel Aviv University, Tel Aviv, Israel; Ilan Levy - Technion Center Of Excellence In Exposure Science And Environmental Health, 6 Technion Israel Institute Of Technology, Israel; David M. Broday - Technion Center Of Excellence In Exposure Science And Environmental Health, 6 Technion Israel Institute Of Technology, Israel; Jeremy D. Kark - Hebrew University-Hadassah 9 School Of Public Health And Community Medicine, Jerusalem, Israel; Noam Levin - Department Of Geography, Hebrew University Of Jerusalem, Israel; David M. Steinberg - Department Of Statistics And Operations Research, School Of Mathematical Sciences, Raymond And Beverly Sackler Faculty Of Exact Sciences, Tel Aviv University, Tel Aviv, Israel; Yuval - Technion Center Of Excellence In Exposure Science And Environmental Health, 6 Technion Israel Institute Of Technology, Israel; Yariv Gerber - Department Of Epidemiology And Preventive Medicine, School Of Public Health, Sackler Faculty Of Medicine, Tel Aviv University, Israel;
Introduction Chronic exposure to traffic-related air pollution has been associated with increased mortality. However, this relationship among myocardial infarction (MI) survivors remains unclear. We investigated the association between chronic exposure to nitrogen oxides (NOx) and all-cause mortality in MI survivors. Methods Participants (n=1,427) aged 65 years or less [mean (SD) age, 54 (8) years; 81% men] admitted to hospital in central Israel with first MI in 1992–1993 were followed through 2011 for survival. Data on demographic, socioeconomic status (SES) and prognostic factors were obtained. Using land-use regression models, annual averages of residential exposure to NOx during follow-up years were estimated individually, according to geocoded home addresses. Addresses were recorded at baseline and were confirmed five years after MI. Unadjusted and adjusted Cox models were used to study the relationship between NOx (average exposure during follow-up) and all-cause mortality, accounting for changes in patients' addresses during follow-up by treating NOx exposure as a time-dependent variable. Results Mean (SD) NOx exposure during follow-up was 26 (7) ppb (range 10–84), with very high correlations (rP≥.97) between annual estimates. Among the participants, 598 (42%) died during a mean (SD) follow-up of 15 (6) years. Incidence density rates among exposure groups were 25.0, 28.8 and 29.7 deaths per 1,000 person-years in the lower, intermediate and upper NOx tertiles, respectively (Ptrend=0.09). Modeling NOx as a continuous variable on a relative scale, an association was found with increased mortality (HR=1.21, 95% CI: 1.09-1.34). That association was attenuated upon adjustment for sociodemographic and clinical factors (1.08, 0.97-1.21). Conclusion A statistically significant association was observed between chronic residential exposure to NOx and all-cause mortality after MI. However, the association was largely attributable to other variables, notably SES differences.