Short-term air pollution concentration variations and ST-elevation myocardial infarction: A case-crossover study from the SCALIM registry.

The relationship between short-term variations of air pollutants concentrations and occurrence of ST-elevated myocardial infarction (STEMI) remains controversial. Most studies have been performed in highly polluted areas. To analyze the association between air pollutant concentrations and admission for STEMI in a low-to-average polluted urban area. We reviewed the medical data of the prospective SCALIM registry to identify all patients (n = 631) admitted between 06/2011 and 12/2018 for STEMI in our department living in the urban area of Limoges, France, and matched them with daily and hourly averaged concentrations of air pollutants (particulate matter ≤ 2.5 μm, PM 2.5 , and ≤ 10 μm PM 10 , nitrogen dioxide, NO 2 , and ozone, O 3) monitored in the same area. Each patient was his/her own control in this study with four control periods in the past month preceding the STEMI case. The risk of STEMI was 30.5% higher with every 10-units PM 10 peak concentration increase in the two hours preceding STEMI symptoms (P < 0.001). This association remained valid despite adjustment for every cardiovascular risk factor, as well as in patients without severe coronary artery disease, or those with ≤ 2 cardiovascular risk factors and those with history of MI. A 10-unit increase in PM 2.5 median concentration in the six hours preceding symptoms was also significatively associated with STEMI but only for patients with ≤ 2 cardiovascular risk factors. The O 3 and NO 2 concentrations were not associated with STEMI. The PM 10 pollution level was associated with the risk of STEMI, even in an area not considered as highly polluted. [ABSTRACT FROM AUTHOR]