The impact of the site of myocardial infarction on in-hospital outcomes for patients with STEMI

Background The territory and vessel involved in ST-elevation myocardial infarction (STEMI) is an important and there are limited contemporary studies from the national perspective. Methods A retrospective cohort study was undertaken of national representative hospital admission in the National Inpatient Sample with a diagnosis of anterior or non-anterior STEMI between 2017 and 2020. Multiple logistic regression and multiple linear regressions were used to determine if there are any differences in in-hospital mortality, length of stay (LOS) and cost for anterior and non-anterior STEMI. Results A total of 655 915 admissions with STEMI were included in the analysis (267 920 anterior STEMI, and 387 995 non-anterior STEMI). Non-anterior STEMI was associated with a significant reduction in mortality (OR 0.91 95% CI 0.89-0.99, P = 0.011) and LOS (coefficient -0.15 95% CI -0.22 to -0.08, P < 0.001) compared to anterior STEMI but there was no significant difference in healthcare costs (-297 95% CI -688 to 74). Analyses considering the infarct-related artery showed that the worse outcomes were associated with left main lesions and left-sided lesions had worse outcomes than right coronary artery lesions. Conclusion Non-anterior STEMI is associated with reduced mortality and LOS compared to anterior STEMI. Left-sided coronary lesions had worse outcomes, compared to right coronary lesions. STEMI should be considered in terms of the vessel or territory affected, in relation to outcomes and healthcare costs.