Women are generally older than men at hospitalization for myocardial infarction (MI)
and also present less frequently with chest pain/discomfort. However, few studies
have taken age into account when examining sex differences in clinical presentation
To examine the relationship between sex and symptom presentation and between sex,
symptom presentation, and hospital mortality, before and after accounting for age
in patients hospitalized with MI.
Observational study from the National Registry of Myocardial Infarction, 1994-2006,
of 1,143,513 registry patients (481,581 women and 661,932 men).
We examined predictors of MI presentation without chest pain and the relationship
between age, sex, and hospital mortality.
The proportion of MI patients who presented without chest pain was significantly higher
for women than men (42.0% [95% CI, 41.8%-42.1%] vs 30.7% [95% CI, 30.6%-30.8%]; P
< .001). There was a significant interaction between age and sex with chest pain at
presentation, with a larger sex difference in younger than older patients, which became
attenuated with advancing age. Multivariable adjusted age-specific odds ratios (ORs)
for lack of chest pain for women (referent, men) were younger than 45 years, 1.30
(95% CI, 1.23-1.36); 45 to 54 years, 1.26 (95% CI, 1.22-1.30); 55 to 64 years, 1.24
(95% CI, 1.21-1.27); 65 to 74 years, 1.13 (95% CI, 1.11-1.15); and 75 years or older,
1.03 (95% CI, 1.02-1.04). Two-way interaction (sex and age) on MI presentation without
chest pain was significant (P < .001). The in-hospital mortality rate was 14.6% for
women and 10.3% for men. Younger women presenting without chest pain had greater hospital
mortality than younger men without chest pain, and these sex differences decreased
or even reversed with advancing age, with adjusted OR for age younger than 45 years,
1.18 (95% CI, 1.00-1.39); 45 to 54 years, 1.13 (95% CI, 1.02-1.26); 55 to 64 years,
1.02 (95% CI, 0.96-1.09); 65 to 74 years, 0.91 (95% CI, 0.88-0.95); and 75 years or
older, 0.81 (95% CI, 0.79-0.83). The 3-way interaction (sex, age, and chest pain)
on mortality was significant (P < .001).
In this registry of patients hospitalized with MI, women were more likely than men
to present without chest pain and had higher mortality than men within the same age
group, but sex differences in clinical presentation without chest pain and in mortality
were attenuated with increasing age.