Twenty Year Trends and Sex Differences in Young Adults Hospitalized With Acute Myocardial Infarction

Abstract

Background: Sex differences are known to exist in the management of older patients presenting with acute myocardial infarction (AMI). Few studies have examined the incidence and risk factors of AMI among young patients, or whether clinical management differs by sex.

Methods: The Atherosclerosis Risk in Communities (ARIC) Surveillance study conducts hospital surveillance of AMI in 4 US communities (MD, MN, MS, and NC). AMI was classified by physician review, using a validated algorithm. Medications and procedures were abstracted from the medical record. Our study population was limited to young patients aged 35 to 54 years.

Results: From 1995 to 2014, 28 732 weighted hospitalizations for AMI were sampled among patients aged 35 to 74 years. Of these, 8737 (30%) were young. The annual incidence of AMI hospitalizations increased for young women but decreased for young men. The overall proportion of AMI admissions attributable to young patients steadily increased, from 27% in 1995 to 1999 to 32% in 2010 to 2014 ( P for trend=0.002), with the largest increase observed in young women. History of hypertension (59% to 73%, P for trend<0.0001) and diabetes mellitus (25% to 35%, P for trend<0.0001) also increased among young AMI patients. Compared to young men, young women presenting with AMI were more often black and had a greater comorbidity burden. In adjusted analyses, young women had a lower probability of receiving lipid-lowering therapies (relative risk [RR]=0.87; 95% confidence interval [CI], 0.80-0.94), nonaspirin antiplatelets (RR=0.83; 95% CI, 0.75-0.91), beta blockers (RR=0.96; 95% CI, 0.91-0.99), coronary angiography (RR=0.93; 95% CI, 0.86-0.99) and coronary revascularization (RR = 0.79; 95% CI, 0.71-0.87). However, 1-year all-cause mortality was comparable for women versus men (HR=1.10; 95% CI, 0.83-1.45).

Conclusions: The proportion of AMI hospitalizations attributable to young patients increased from 1995 to 2014 and was especially pronounced among women. History of hypertension and diabetes among young patients admitted with AMI increased over time as well. Compared with young men, young women presenting with AMI had a lower likelihood of receiving guideline-based AMI therapies. A better understanding of factors underlying these changes is needed to improve care of young patients with AMI.

Keywords: acute myocardial infarction; epidemiology; sex differences.

Figure 1:

Temporal trends in the incidence of acute myocardial infarction among residents of the ARIC communities who are young (35–54 years), [Panel A]; the percentage of total ARIC communities residents (35–74 years) who are young (35–54 years), [Panel B]; and the percentage of 35–74-year-old patients admitted with acute myocardial infarction who are young (35–54 years), [Panel C]. The Atherosclerosis Risk in Communities Surveillance Study, 1995–2014.

Figure 2:

Prevalence and temporal trends in cardiovascular risk factors among young (35–54 years) women and men presenting with acute myocardial infarction. The Atherosclerosis Risk in Communities Surveillance Study, 1995–2014.

Figure 3:

Annual trends* in administration of guideline-directed therapies among young (35–54 years) women and men presenting with acute myocardial infarction. The Atherosclerosis Risk in Communities Surveillance Study, 1995–2014. *Footnote: Non-aspirin antiplatelets not routinely abstracted prior to 1996. Lipid lowering agents not routinely abstracted prior to 1998

Figure 4:

Relative probabilities* of young women vs. young men receiving guideline-directed therapies for acute myocardial infarction. The Atherosclerosis Risk in Communities Surveillance study, 1995–2014. Footnote: Models adjusted for race, geographic location (Forsyth County, NC; Jackson, MS; Minneapolis, MN; or Washington County, MD), and year of hospital admission).