Study on the association of air pollution and acute myocardial infarction

Objective:
Air pollutants have attracted increasing interest worldwide, including Korea. Acute and chronic exposure to air pollutants has adverse effects on health. Therefore, this study examined the association of air pollutants with myocardial infarction.
Method:
This study included 542 patients who underwent coronary angiography and were diagnosed with acute coronary artery occlusion after visiting a local emergency medical center from January 1, 2016, to December 31, 2018. The days (1,096) were divided into two groups: myocardial infarction days group (the days when symptoms of myocardial infarction developed) and non-myocardial infarction days group (the days when symptoms of myocardial infarction did not develop). This study compared the air pollutants (PM10, PM2.5, O₃, SO₂, CO, and NO₂) and prognosis (survivor, death) from two days ago to the days between the myocardial infarction days and non-myocardial infarction days.
Results:
The PM10 and PM2.5 of the myocardial infarction days group were 44.332±18.892 and 25.193±12.009 μm/m³, respectively, and those of the non-myocardial infarction days group were 41.906±19.263 and 23.693±12.053 μm/m³, respectively. On day one before symptom development, the PM2.5 of the myocardial infarction days group was 25.316± 11.977 μm/m³, which was higher than that of the non-myocardial infarction days groups (23.642±12.053 μm/m³), and there were no significant differences between the gaseous air pollution and the number of occlusions, except on a 0 day of ozone. The PM2.5 (proximal, middle, and distal according to the vessel size) at day 0 was 25.747±12.361, 22.941± 11.477, and 21.486±10.924 μm/m³, respectively; the proximal group had the highest value. During the study days, the PM10 of the death and survival groups was 51.440 (±20.140)-56.924 (±25.225) μm/m³ and 41.155 (±18.544)-43.002 (±18.858) μm/m³, respectively. PM2.5 of the death and survival groups was 26.968 (±14.140)-30.145 (±12.829) and 23.770 (±11.685)-24.170 (±12.696) μm/m³, respectively.
Conclusion:
Myocardial infarction was found to develop more on the day with the highest PM2.5 and PM10 on day 0 and -1. A high PM2.5 is related to an occlusion of the proximal coronary artery. Therefore, PM2.5 has a stronger association with myocardial infarction than PM10. Furthermore, increased particulate air pollution for three consecutive days is associated with a poor prognosis.

Key words: Air pollution; Myocardial infarction; Particulate matter