PM chemical components are associated with in-hospital case fatality among acute myocardial infarction patients in China.

Recent studies have linked the cardiovascular events with the exposure to ambient fine particulate matter (PM); however, the impact of PM chemical components on acute myocardial infarction (AMI) case fatality remains poorly understood. To address this gap, we included 178,340 hospitalised patients with AMI utilising the inpatient discharge database from Sichuan, Shanxi, Guangxi, and Guangdong, China spanning 2014-2019. We evaluated exposure to PM and its components (black carbon (BC), organic matter (OM), sulphate (SO), nitrate (NO), and ammonium (NH)) using bilinear interpolation based on the patient's residential address. We used mixed-effects logistic regression models to investigate the associations of PM and its five components with in-hospital AMI case fatality. Per interquartile range (IQR) increment in short-term exposure (7-day average) to overall PM (odds ratio (OR): 1.086, 95 % confidence interval (CI): 1.045-1.128), SO(1.063, 1.024-1.104), BC (1.055, 1.023-1.089), OM (1.052, 1.019-1.086, and NO (1.045, 1.003-1.089) were significantly associated with high risk of in-hospital AMI case fatality. The ORs per IQR increment in long-term exposure (annual average) were 1.323 (95 % CI: 1.255-1.394) for PM, followed by BC (1.271, 1.210-1.335), OM (1.243, 1.188-1.300), SO (1.212, 1.157-1.270), NO (1.116, 1.075-1.159), and NH (1.068, 1.031-1.106). Our study suggests that PM chemical components might be important risk factors for in-hospital AMI case fatality, highlighting the importance of targeted reduction of PM emissions, particularly BC, OM, and SO.