Abstract and Introduction
Abstract
Background Various national campaigns launched in recent years have focused on young women with acute myocardial infarctions (AMIs). Contemporary longitudinal data about sex differences in clinical characteristics, hospitalization rates, length of stay (LOS), and mortality have not been examined.
Objectives This study sought to determine sex differences in clinical characteristics, hospitalization rates, LOS, and in-hospital mortality by age group and race among young patients with AMIs using a large national dataset of U.S. hospital discharges.
Methods Using the National Inpatient Sample, clinical characteristics, AMI hospitalization rates, LOS, and in-hospital mortality were compared for patients with AMI across ages 30 to 54 years, dividing them into 5-year subgroups from 2001 to 2010, using survey data analysis techniques.
Results A total of 230,684 hospitalizations were identified with principal discharge diagnoses of AMI in 30- to 54-year-old patients from Nationwide Inpatient Sample data, representing an estimated 1,129,949 hospitalizations in the United States from 2001 to 2010. No statistically significant declines in AMI hospitalization rates were observed in the age groups <55 years or stratified by sex. Prevalence of comorbidities was higher in women and increased among both sexes through the study period. Women had longer LOS and higher in-hospital mortality than men across all age groups. However, observed in-hospital mortality declined significantly for women from 2001 to 2010 (from 3.3% to 2.3%, relative change 30.5%; p for trend < 0.0001) but not for men (from 2% to 1.8%, relative change 8.6%; p for trend = 0.60).
Conclusions AMI hospitalization rates for young people have not declined over the past decade. Young women with AMIs have more comorbidity, longer LOS, and higher in-hospital mortality than young men, although their mortality rates are decreasing.
Introduction
Each year, more than 30,000 women younger than 55 years of age are hospitalized with acute myocardial infarction (AMI) in the United States alone. Growing public recognition of the importance of heart disease in young women in the late 1990s and early 2000s led to several national campaigns and evidence-based guidelines with a focus on young women. However, contemporary data about trends in clinical characteristics, hospitalization, and mortality rates of young patients with AMI are lacking. Moreover, patients younger than 55 years of age with AMIs have been historically examined collectively in prior studies, yielding little insight into the relationships of age and race with sex differences in the epidemiology of this disease within that group.
Accordingly, we studied sex differences in patient characteristics, hospitalization rates, and short-term outcomes among a national sample of patients 30 to 54 years of age with AMIs from 2001 through 2010. Specifically, we examined temporal trends with attention to subgroups of age and race. We used data from the Nationwide Inpatient Sample (NIS), a national all-payer administrative database, and U.S. census data to obtain a national perspective on recent trends. Then, we stratified secondary analyses by age, race, and sex subgroups in the 21 states that collected data on race during this time period.