Long-Term Air Pollution Exposure and Heart Failure in the Rome Longitudinal Study

Abstract

Background Some studies have shown an association between acute air pollution exposure and aggravation of heart failure, but the role of long-term exposure has been less investigated. The objective of this study was to analyze the association between long- term exposure to fine particles (PM2.5) and nitrogen dioxide (NO2) with first hospitalization for heart failure in Rome, Italy. Methods The Rome Longitudinal Study includes 1,265,058 adults enrolled in 2001 and followed for 9 years. Average residential exposure to NO2 (by land use regression model) and PM2.5 (by Chemical Transport dispersion model) for the 5 years before the inclusion were available. We used Cox regression to evaluate the association between pollutants and first hospitalization for heart failure or fatal heart failure (deaths within 28 days from the hospital admission), adjusting for several factors. We used age as time scale, stratified the models by sex, and adjusted for level of education, marital status, place of birth, occupation, area-based socioeconomic position, comorbidity, including previous acute coronary events. Results During the follow-up, among the 1,252,880 subjects never admitted to hospital for heart failure at baseline, 37,200 had a hospital admission for the condition under study (and 17.8% died within 28 days). There was a 2% increased risk in being hospitalized for heart failure each 10ug/m3 increase in PM2.5 exposure during 1996-2000 (HR=1.02, 95%CI: 1.00-1.05), while the NO2 effect was lower (HR=1.01, 95%CI: 0.99-1.02 for 10ug/m3 increase in NO2). There was a strong association between long-term exposure to both pollutants and fatal events: HR=1.05 (95%CI: 1.02-1.09) for 10ug/m3 increase in NO2, and HR=1.16 (95%CI: 1.09-1.23) for 10ug/m3 increase in PM2.5 average exposure in the 5 years before the inclusion. Conclusions We found evidence of a link between long-term exposure to air pollution and first hospital admission for heart failure, in particular with fatal events.