Influences of socioeconomic and environmental factors on STEMI incidence and related mortality: Insights from the Belgian Environmental Myocardial Infarction Risk (EMIR) Study

Abstract

Abstract Background Current risk models for myocardial infarction incidence and post-event mortality primarily rely on clinical parameters and do not account for environmental or socioeconomic factors. We aimed to provide a more comprehensive assessment of determinants of ST-elevation myocardial infarction (STEMI) admission and in-hospital mortality. Methods We analyzed nine years of national hospital discharge data of all STEMI admissions in Belgium (2012–2014, 2016–2021). Acute and chronic exposures to PM2.5, NO2, O3, temperature, noise, and greenspace were estimated at residential addresses using high-resolution models. Individual socioeconomic data were linked from administrative records. A time-stratified case-crossover design assessed associations between short-term air pollution exposures and STEMI admission, including delayed associations. Multivariable logistic regression examined clinical, socioeconomic, and environmental determinants of in-hospital mortality. Results A total of 51,544 STEMI admissions were identified (51.4 per 100,000 inhabitants/year). Interquartile range increases in PM2.5 and NO2 were associated with higher same-day STEMI admission risk (PM2.5: OR 1.022, 95%CI 1.008–1.035; NO2: OR 1.044, 95%CI 1.025–1.063). O3 showed associations over delayed exposure windows (strongest at lag 0–2: OR 1.063, 95% CI 1.034–1.090). In-hospital mortality was 11.8% and was most strongly associated with socioeconomic factors, including lower individual and area-level income and retirement status, alongside clinical characteristics. Conclusions Environmental factors through air pollution are associated with STEMI incidence, whereas socioeconomic factors such as financial precarity are related to in-hospital mortality. New risk models integrating socioeconomic and environmental vulnerabilities are needed to ensure an early recognition and reinforced care for patients at risk of adverse outcomes.