Abstract Body (Do not enter title and authors here): BACKGROUND: With limited data on recent outcomes, ST-segment elevation myocardial infarction (STEMI) continues to be a significant public health issue in the modern day. This study aims to evaluate the most recent trends in 30-day readmission rate (30-dRr), mortality, and resource utilization associated with STEMI.

METHODOLOGY: We utilized the Nationwide Readmission Database to analyze data from 2016 to 2021. Patients aged ≥ 18 years with STEMI identified using ICD-10 codes. The primary aim was trends in 30-day readmission rates (30-dRr). Secondary objectives included investigating mortality rates, resource utilization measured by LOS, and mean hospital costs adjusted for inflation & identifying readmission most common diagnosis (R-MCD) readmission. The study employed predictive marginal effects over years & regression analyses.

RESULTS: In recent years, we noticed a decrease in the total number of Index Admissions for STEMI, declining from 508,179 (203 per 100,000 person-year) in 2016 to 457,790 (177 per 100,000 person-year) in 2021 (p trend = 0.001). The median age at index admission was 74.2 years (SD ± 13), with males accounting for 58.8%. Among readmitted patients, the average age was 69.4 years (SD ± 13.7), with males at 58.6%. The 30-day readmission rate has consistently decreased from 9.84% in 2016 to 7.97% in 2021 (p trend = 0.001). The mortality rates for both index admission and readmission have remained stable over the years at 3.14% and 3.15%, respectively, in 2016, and 3.0% and 2.9%, respectively, in 2021 (p trend = 0.4 and 0.1, respectively). The mean LOS for index admission has decreased from 3.8 days in 2016 to 3.5 days in 2021 (p trend = 0.001), with readmission LOS showing a similar decrease from 4.0 days in 2016 to 3.8 days in 2021 (p trend = 0.001). Additionally, the inflation-adjusted mean hospital costs have risen over the years, increasing from $23,758.4 in 2016 to $26,038 in 2021 for index admission (p trend = 0.001) and from $15,335.5 in 2016 to $17,662 in 2021 for readmission (p trend = 0.001). The R-MCD was acute coronary syndrome (25%) and heart failure (23%)

CONCLUSION: We observed a decrease in the prevalence of STEMI, accompanied by a reduction in the 30-dRr during the study year. Despite stable index and readmission trend mortality outcomes, the LOS has progressively decreased with a rise in hospitalization costs. Further prospective studies are crucial for risk stratification to effectively guide mortality outcomes & cost.