Abstract 4363122: Temporal Trends in Major Adverse Cardiovascular Events Following Hospitalization for Myocardial Infarction Between 2008-2022: Insights from the Veterans Affairs Healthcare System

Background: Over 800,000 individuals are hospitalized for a myocardial infarction (MI) annually in the United States. Temporal trends in post-discharge outcomes are uncertain. Question: Among Veterans who survive an MI hospitalization, how have post-discharge outcomes changed? Methods: Veterans who survived an MI hospitalization within or outside the VHA between 2008-2022 were identified based on a principal diagnosis of MI from an acute care hospitalization. We identified comorbidities, vital signs, and laboratory values pre-hospitalization. The primary outcome was a 4-point composite MACE (death, MI, ischemic stroke, and heart failure (HF) hospitalization) over 1 year post-discharge. Temporal trends were analyzed by comparing outcomes across 3 time periods (2008-2012, 2013-2017, and 2018-2022) with the Cuzick rank test. We also evaluated 1-year death alone and performed a landmark analysis evaluating 1-year death following HF hospitalization within the first 12 months post-MI. The annual change in outcomes was examined while adjusting for demographics, comorbidities, pre-admission vital signs and laboratory values, and STEMI vs. NSTEMI classification. Results: There were 444,659 Veterans with a non-fatal MI hospitalization between 2008 and 2022. The median age was 73 (interquartile range: 66-80) and 1.8% were women. Over time, the proportion with STEMI decreased (2008-2012: 26.1%, 2013-2017: 23.1%, and 2018-2022: 23.1%; p<0.01). The proportion with inpatient revascularization decreased from 49.6% to 48.1% to 36.9% (p<0.01). The 1-year risk of the composite MACE outcome decreased from 26.1% to 23.2% to 22.2% (p<0.01) across time periods. After adjustment, there was a 3.9% annual relative decrease in the odds of 1-year MACE (OR: 0.965; 95% CI: 0.963-0.967). The risk of 1-year death post-MI hospitalization decreased from 20.7% to 18.1% to 16.3% (p<0.01) (Figure). After adjustment, there was a 4.2% annual relative decrease in the odds of 1-year mortality (OR 0.958 per year; 95% CI: 0.956-0.960). There were 23,048 (5.2%) Veterans with HF hospitalization within 12 months of MI discharge. Among this cohort, 44.9% died within 1-year post-HF hospitalization. Conclusion: Among Veterans, the risk of death post-MI hospitalization has improved over time. However, over 1 in 5 Veterans post-MI continue to have major adverse cardiovascular outcomes within 1 year. Veterans with a HF hospitalization post-MI are at substantially elevated risk of death.