Exploring the Relationship between Acute Coronary Syndrome, Lower Respiratory Tract Infections, and Atmospheric Pollution

<b>Background</b>: Respiratory infections were found to be connected with the incidence of acute coronary syndrome (ACS). The proposed pathway of this connection includes inflammation, oxidative stress, pro-coagulation, and atherosclerotic plaque destabilization. This can cause rapture and thrombus formation, leading to ACS. Our study aimed to assess the risk factors for coronary artery thrombosis as a manifestation of ACS and for lower respiratory tract infections (LRTIs) in patients with ACS. <b>Methods</b>: The study included 876 patients with ACS from January 2014 to December 2018. Both the clinical data and air pollution data were analyzed. Statistical tests used for analysis included Student's <i>t</i>-test, the Mann-Whitney U-test, the Chi-squared test, and the odds ratio Altman calculation. <b>Results</b>: LRTIs were found in 9.13% patients with ACS. The patients with LRTI had a higher risk of coronary artery thrombosis (OR: 2.4903; CI: 1.3483 to 4.5996). Moreover, they had increased values of inflammatory markers, were older, had a lower BMI, and a higher rate of atrial fibrillation. The average atmospheric aerosols with a maximum diameter of 2.5 μm (PM_2.5 concentration) from three consecutive days before hospitalization for ACS were higher in patients with LRTI. <b>Conclusions</b>: The occurrence of coronary artery thrombosis was higher among the patients with LRTI during ACS. PM_2.5 exposition was higher in the three consecutive days before hospitalization in patients with LRTI during ACS.