Sex Differences in Outcomes of Young Adults Hospitalized With First Myocardial Infarction From 2011 to 2022

Background Acute myocardial infarction (AMI) hospitalizations are increasing in young adults, but outcomes stratified by sex and AMI subtype are not well understood. Methods First AMI hospitalizations among young adults 18 to 54 years old were analyzed from 2011 to 2022 in the United States from the National Inpatient Sample and stratified by subtype (ST‐segment–elevation myocardial infarction [STEMI] and non–ST‐segment–elevation myocardial infarction) and sex. In‐hospital mortality by first AMI‐subtype was the primary outcome, including in‐hospital mortality trends using orthogonal polynomial contrasts; in‐hospital complications were secondary outcomes. Patient characteristics included traditional and nontraditional risk factors. All analyses were performed sex‐stratified with adjustment using a sequential additive multivariable logistic regression model. Results Among 945 977 weighted first AMI hospitalizations in young adults, 356 115 (37.6%) were STEMI and 589 862 (62.4%) were non–ST‐segment–elevation myocardial infarction. Overall, adjusted in‐hospital mortality increased significantly for first STEMI (1.2% absolute increase, P trend