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

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.