Effect of air pollution on the number of hospital admissions for acute coronary syndrome in elderly patients

INTRODUCTION Air pollution is a documented risk factor for cardiovascular diseases. OBJECTIVES The aim of the study was to assess the effect of air pollution on the number of hospital admissions for acute coronary syndrome (ACS) in elderly patients. PATIENTS AND METHODS The medical records of 26 695 patients hospitalized for ACS between 2008 and 2017 were examined. Weather conditions and the following components of air pollution were analyzed: sulfur dioxide, nitrogen dioxide, and particulate matter with a diameter of 2.5 mu m or less (PM2.5) and a diameter of 10 mu m or less (PM10). RESULTS The study included 1618 inhabitants of Bialystok in Poland (mean [SD] age, 75 [6.4] years; men, 52.6%). The norm for PM2.5 was exceeded on 23.5% of days, while for PM10, on 5.3% of days. Elevated PM10 levels were associated with a higher number of hospitalizations for ACS on the day of exposure (mean [SD], 0.61 [0.78] vs 0.44 [0.69]; P<0.001), and this effect persisted in the subsequent days (mean [SD], 1.07 [1.07] vs 0.88 [1.00]; P = 0.02). An increase of PM10 concentrations by 10 mu g/m(3) was associated with an increase in the number of hospitalizations due to unstable angina, and significant effects were observed even after 6 days (rate ratio, 1.16; 95% CI, 1.03-1.32; P = 0.02). CONCLUSIONS Increased exposure to air pollution, in particular, elevated PM10 levels, is associated with a higher incidence of ACS both on the day of exposure and over the following days.