Sex differences in evaluation and outcome of unstable angina.

CONTEXT: The existence of sex bias in the delivery of cardiac care is controversial, and little is known about the association between sex and delivery of care and outcomes at an early point in the diagnostic sequence, such as when patients present for the evaluation of chest pain.

OBJECTIVE: To test the hypothesis that female sex is negatively associated with care delivered to and outcomes of persons diagnosed as having unstable angina.

DESIGN: Inception population-based cohort study with an average of 6 years of follow-up.

SETTING: Emergency departments (EDs) in Olmsted County, Minnesota.

PATIENTS: A total of 2271 Olmsted County residents (1306 men and 965 women) who presented to the ED for the first time with symptoms meeting criteria for unstable angina between 1985 and 1992.

MAIN OUTCOME MEASURES: Use of cardiac procedures within 90 days of ED visit, overall mortality, and cardiac events (cardiac death, nonfatal myocardial infarction, nonfatal cardiac arrest, and congestive heart failure), compared by sex and Agency for Health Care Policy and Research cardiovascular risk category (low, intermediate, or high).

RESULTS: Women were older (P<.001), more likely to have a history of hypertension (P = .001), and less likely to present with typical angina (P = .004) than men. Men were more likely than women to undergo noninvasive cardiac tests (relative risk [RR], 1.27; 95% confidence interval [CI], 1.14-1.40) as well as invasive cardiac procedures (RR, 1.72; 95% CI, 1.51-1.97). After adjustment, male sex was associated with a 24% increase in the use of cardiac procedures. Survival of both men and women in the high and intermediate risk categories was significantly lower than expected per the general population (P<.001). Women had a worse outcome than men, but after multivariate adjustment, male sex was associated with a trend toward an increase in the risk of death (RR, 1.23; 95% CI, 0.99-1.54) and significantly associated with increased risk of cardiac events (RR, 1.21; 95% CI, 1.03-1.42).

CONCLUSIONS: Our population-based data indicate that after an ED visit for symptoms of unstable angina, the use of cardiac procedures was lower in women, but after taking into account baseline characteristics, men experienced worse outcomes.