Abstract Body (Do not enter title and authors here):
Introduction:
Anterior ST-segment elevation myocardial infarction (STEMI) with left bundle branch block (LBBB) represents a high-risk clinical scenario requiring urgent revascularization. While hospital characteristics (size, location, teaching status) are known to influence STEMI outcomes broadly, their specific impact on mortality, resource utilization (length of stay, LOS), and costs (total charges) in this vulnerable subgroup remains incompletely characterized. This study aims to evaluate associations between hospital characteristics and these key outcomes among anterior STEMI patients with LBBB using a large, nationally representative cohort.

Methods:
Using the National Inpatient Sample (NIS)(2018-2022), we analyzed anterior STEMI patients with LBBB. Van Walraven Weighted Elixhauser Comorbidity index was used to survey linear and logistic regression models with multiple covariates assessing associations between hospital characteristics—size (small [reference], medium, large) and location (rural [reference], urban non-teaching, urban teaching)—and outcomes: mortality, length of stay (LOS), and total charges. Adjusted odds ratios (OR) and β coefficients with 95% confidence intervals (CI) were calculated.

Results:
Among 167,350 anterior STEMI patients with LBBB, urban non-teaching hospitals (OR: 0.61; 95% CI: 0.46-0.82; p=0.01) and urban teaching hospitals (OR: 0.71; 95% CI: 0.54-0.91; p=0.007) showed lower odds of mortality versus small hospitals.The mean LOS for patients who died was 5.2 days vs 6.4 in rest of the population. Medium hospitals (β: 0.33 days; 95% CI: 0.20-0.46; p<0.001), large hospitals (β: 1.05 days; 95% CI: 0.91-1.18; p<0.001), urban non-teaching (β: 0.52 days; 95% CI: 0.35-0.70; p<0.001), and urban teaching hospitals (β: 1.23 days; 95% CI: 1.06-1.39; p<0.001) had longer LOS versus small/rural hospitals respectively. Additionally, higher charges occurred at large hospitals (β: $22,373; 95% CI: $16,606-$28,140; p<0.001), urban non-teaching (β: $30,591; 95% CI: $24,058-$37,125; p<0.001), and urban teaching hospitals (β: $37,342; 95% CI: $31,442-$43,243; p<0.001).

Conclusion:
Hospital characteristics significantly influence clinical outcomes in patients with anterior STEMI and LBBB. These findings highlight the need for standardized care pathways and strategic resource allocation to optimize outcomes across diverse care settings.